mineral resources and mineral reserves, collahuasi …...mineral resources and mineral reserves,...

29 March 2012

XSTRATA CANADA CORPORATION

Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Tarapacá Region, Chile

Prepared by: Golder Associates S.A. Magdalena, 181, piso 3 Las Condes, Santiago Chile

Effective Date: December 31, 2011

TECH

NICA

L RE

PORT

Report Number: 1292154001 Qualified Persons: Marcelo Godoy, MAusIMM (CP) Ronald Turner, MAusIMM (CP) Juan Pablo González, Chilean Mining Commission

Prepared for:Xstrata Canada Corporation 100 King Street West Suite 6900 Toronto, Ontario M5X 1E3 Canada

MINERAL RESOURCES AND MINERAL RESERVES, COLLAHUASI COPPER MINE

29 March 2012 Report No. 1292154001 1

Table of Contents

1.0 SUMMARY ........................................................................................................................................................................ 9

1.1 Scope .................................................................................................................................................................. 9

1.2 Notes to the report ............................................................................................................................................. 10

1.3 Property description and ownership ................................................................................................................... 11

1.4 Geology and mineralization ............................................................................................................................... 11

1.5 Status of exploration .......................................................................................................................................... 11

1.6 Development and operations ............................................................................................................................. 11

1.7 Mineral resource and mineral reserve estimates ............................................................................................... 12

1.8 Conclusions and recommendations ................................................................................................................... 16

2.0 INTRODUCTION ............................................................................................................................................................. 17

3.0 RELIANCE ON OTHER EXPERTS ................................................................................................................................ 18

4.0 PROPERTY DESCRIPTION AND LOCATION ............................................................................................................... 19

4.1 Location ............................................................................................................................................................. 19

4.2 Claim status ....................................................................................................................................................... 19

4.2.1 Surface and camps rights ............................................................................................................................ 21

4.2.2 Water rights and right of way ....................................................................................................................... 22

4.3 Property boundaries and location of mineralized zones .................................................................................... 22

4.4 Nature and extent of issuers title ....................................................................................................................... 23

4.5 Environmental liabilities ..................................................................................................................................... 23

4.6 Future work ........................................................................................................................................................ 24

4.6.1 Growth projects for the concentrate line: ...................................................................................................... 24

4.6.2 Growth projects for the cathodes line: .......................................................................................................... 24

5.0 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY ............................ 25

5.1 Accessibility ....................................................................................................................................................... 25

5.2 Climate and physiography ................................................................................................................................. 25

5.3 Infrastructure and camp facilities ....................................................................................................................... 25

6.0 HISTORY ........................................................................................................................................................................ 25

7.0 GEOLOGICAL SETTING AND MINERALIZATION ....................................................................................................... 26


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7.1 Regional geology ............................................................................................................................................... 26

7.2 Local geology .................................................................................................................................................... 29

7.2.1 Mineralisation ............................................................................................................................................... 29

7.2.2 Lithology ....................................................................................................................................................... 31

7.2.3 Alteration ...................................................................................................................................................... 33

8.0 DEPOSIT TYPES ............................................................................................................................................................ 35

9.0 EXPLORATION .............................................................................................................................................................. 36

10.0 DRILLING ....................................................................................................................................................................... 37

10.1 Down hole survey .............................................................................................................................................. 38

10.2 Topographic Survey ........................................................................................................................................... 39

11.0 SAMPLE PREPARATION, ANALYSES AND SECURITY ............................................................................................. 39

11.1 Logging .............................................................................................................................................................. 39

11.2 Drill hole sampling ............................................................................................................................................. 39

11.3 Database Management ..................................................................................................................................... 41

11.4 QAQC ................................................................................................................................................................ 41

11.4.1 Rosario Oeste QAQC ................................................................................................................................... 41

11.4.2 Rosario QAQC ............................................................................................................................................. 42

11.4.2.1 Capella ..................................................................................................................................................... 44

12.0 DATA VERIFICATION .................................................................................................................................................... 45

13.0 MINERAL PROCESSING AND METALLURGICAL TESTING ...................................................................................... 46

13.1 Mineral processing ............................................................................................................................................. 46

13.2 Metallurgical testing ........................................................................................................................................... 47

14.0 MINERAL RESOURCE ESTIMATES ............................................................................................................................. 48

14.1 History ............................................................................................................................................................... 48

14.2 Geological interpretation .................................................................................................................................... 51

14.3 Model definition.................................................................................................................................................. 54

14.4 Contact analysis ................................................................................................................................................ 54

14.5 Risk adjustment ................................................................................................................................................. 56

14.6 Variography ....................................................................................................................................................... 56

14.7 Grade interpolation ............................................................................................................................................ 58


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14.7.1 Rosario ......................................................................................................................................................... 58

14.7.2 Rosario Oeste .............................................................................................................................................. 58

14.7.3 Ujina ............................................................................................................................................................. 58

14.7.4 Rosario Sur .................................................................................................................................................. 59

14.7.5 Capella ......................................................................................................................................................... 59

14.8 Bulk density model ............................................................................................................................................. 60

14.9 Validation of block model estimates ................................................................................................................... 60

14.10 Resource Classification ..................................................................................................................................... 64

14.11 Dilution Considerations ...................................................................................................................................... 66

14.12 Resource Definition ........................................................................................................................................... 66

14.13 Mineral Resource Statement ............................................................................................................................. 68

15.0 MINERAL RESERVE ESTIMATES ................................................................................................................................ 70

16.0 MINING METHODS ........................................................................................................................................................ 73

16.1 Life of Mine Plan ................................................................................................................................................ 73

16.2 Mine planning process ....................................................................................................................................... 73

16.3 Whittle optimization ............................................................................................................................................ 74

16.3.1 Costs and Prices .......................................................................................................................................... 75

16.3.2 Pit slopes ..................................................................................................................................................... 76

16.3.3 Optimisation results...................................................................................................................................... 76

16.4 Pit Design .......................................................................................................................................................... 77

16.5 Cut-off Grades ................................................................................................................................................... 79

16.6 Production Scheduling ....................................................................................................................................... 80

17.0 RECOVERY METHODS ................................................................................................................................................. 82

17.1 Ujina Pit ............................................................................................................................................................. 82

17.2 Rosario Pit ......................................................................................................................................................... 82

17.3 Rosario Sur I & II Pits ........................................................................................................................................ 82

18.0 PROJECT INFRASTRUCTURE ..................................................................................................................................... 83

18.1 Concentrator ...................................................................................................................................................... 83

18.2 Oxide plants ....................................................................................................................................................... 83

18.3 Other infrastructure ............................................................................................................................................ 83


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19.0 MARKET STUDIES AND CONTRACTS ........................................................................................................................ 84

19.1 Markets .............................................................................................................................................................. 84

19.2 Contracts ........................................................................................................................................................... 84

20.0 ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY IMPACT ............................................. 84

21.0 CAPITAL AND OPERATING COSTS ............................................................................................................................ 85

22.0 ECONOMIC ANALYSIS ................................................................................................................................................. 87

23.0 ADJACENT PROPERTIES ............................................................................................................................................. 88

24.0 OTHER RELEVANT DATA AND INFORMATION ......................................................................................................... 89

24.1 Historical Production .......................................................................................................................................... 89

25.0 INTERPRETATION AND CONCLUSIONS ..................................................................................................................... 90

26.0 RECOMMENDATIONS ................................................................................................................................................... 90

27.0 REFERENCES ................................................................................................................................................................ 91

APPENDICES

Appendix A Certificates of Qualified Persons


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TABLES Table 1-1: Abbreviations .......................................................................................................................................................... 10

Table 1-2: CMDIC Mineral Resources for the Rosario deposit as at 31 December 2011 ........................................................ 12

Table 1-3: CMDIC Mineral Resources for the Rosario Oeste deposit as at 31 December 2011 .............................................. 12

Table 1-4: CMDIC Mineral Resources for the Ujina deposit as at 31 December 2011 ............................................................. 13

Table 1-5: CMDIC Mineral Resources for the oxide deposits as at 31 December 2011 .......................................................... 13

Table 1-6: CMDIC Total Mineral Resources as at 31 December 2011 .................................................................................... 13

Table 1-7: CMDIC Mineral Reserves for the Rosario deposit as at 31 December 2011 .......................................................... 14

Table 1-8: CMDIC Mineral Reserves for the Ujina deposit as at 31 December 2011 ............................................................... 15

Table 1-9: CMDIC Mineral Reserves for the Oxide deposits as at 31 December 2011 ............................................................ 15

Table 1-10: CMDIC Mineral Reserves in Stocks as at 31 December 2011 .............................................................................. 15

Table 1-11: CMDIC Total Mineral Reserves as at 31 December 2011 .................................................................................... 15

Table 4-1: Concession name and surface ................................................................................................................................ 20

Table 4-2: Surfaces for CMDIC infrastructure and mine lots .................................................................................................... 21

Table 4-3: UTM coordinates for the property containing mineral resources and mineral reserves ........................................... 22

Table 10-1: Drilling summary for data supporting the CMDIC resource models....................................................................... 37

Table 11-1: Mechanical preparation procedure. ....................................................................................................................... 40

Table 14-1: Rosario resource model history ............................................................................................................................. 49

Table 14-2: Ujina resource model history ................................................................................................................................. 50

Table 14-3: Rosario Sur resource model history ...................................................................................................................... 50

Table 14-5: Units considered in the Ujina mineralisation model. .............................................................................................. 52

Table 14-6: CMDIC Resource model definitions ...................................................................................................................... 54

Table 14-7: Resource classification criteria: Rosario and Ujina ............................................................................................... 64

Table 14-8: Data configuration for resource classification runs: Rosario ................................................................................. 64

Table 14-9: Data configuration for resource classification runs: Ujina ...................................................................................... 65

Table 14-10: Resource classification criteria: Rosario Sur I ..................................................................................................... 65

Table 14-11: Resource classification criteria: Rosario Sur II and III ......................................................................................... 65

Table 14-12: CMDIC mineral resources for the Rosario deposit as at 31 December 2011 ...................................................... 68

Table 14-13: CMDIC mineral resources for the Rosario Oeste deposit as at 31 December 2011 ........................................... 68

Table 14-14: CMDIC mineral resources for the Ujina deposit as at 31 December 2011 .......................................................... 68

Table 14-15: CMDIC mineral resources for the exotic oxide deposits as at 31 December 2011 .............................................. 69

Table 15-1: CMDIC Mineral Reserves for the Rosario deposit as at 31 December 2011 ........................................................ 71

Table 15-2: CMDIC Mineral Reserves for the Ujina deposit as at 31 December 2011 ............................................................. 71

Table 15-3: Mineral Reserves for the Oxide deposits as at 31 December 2011 ...................................................................... 71


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Table 15-4: CMDIC mineral reserves in Stocks ....................................................................................................................... 72

Table 16-1: Summary of LOM plan .......................................................................................................................................... 74

Table 16-2 Whittle mining costs ............................................................................................................................................... 75

Table 16-3 Whittle processing costs ........................................................................................................................................ 75

Table 16-4: Whittle copper and molybdenum price and selling cost ........................................................................................ 75

Table 16-5: Summary of Final Pit Results for Rosario and Ujina ............................................................................................. 77

Table 16-6: Mine design parameters ........................................................................................................................................ 77

Table 16-7: Cut-off Grade by Year ........................................................................................................................................... 79

Table 16-8: Life-of-Mine Plan ................................................................................................................................................... 80

Table 17-1: Treatment capacity and Recovery (P80 of 230 [um]) ............................................................................................ 82

Table 22-1: Project Net Cash Flow (US$ million, undiscounted) .............................................................................................. 87


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FIGURES Figure 4-1: CMDIC location map .............................................................................................................................................. 19

Figure 4-2: CMDIC mining property layout ............................................................................................................................... 20

Figure 4-3: CMDIC mining operation layout ............................................................................................................................. 23

Figure 4-4: Summary of CMDIC's growth strategy ................................................................................................................... 24

Figure 7-1: Regional schematic showing the Eocene-Oligocene porphyry copper belt. ........................................................... 27

Figure 7-2: Regional schematic W-E geological section of the CMDIC district showing the distribution of the major mineralised systems. ............................................................................................................................................... 28

Figure 7-3: District schematic geology for the Collahuasi area. ............................................................................................... 29

Figure 7-4: Typical mineralisation cross section of Rosario at 20NE, looking to NW ............................................................... 30

Figure 7-5: Typical mineralisation cross section of Ujina at 128NE, looking to NE .................................................................. 31

Figure 7-6: Typical lithology cross section of Rosario at 20NE, looking to NW (CMDIC internal presentation) ........................ 32

Figure 7-7: Typical lithology cross section of Ujina at 128NE, looking to NE ........................................................................... 33

Figure 7-8: Typical alteration cross section of Rosario at 20NE, looking to NW (CMDIC internal presentation) ...................... 35

Figure 7-9: Typical alteration cross section of Ujina at 128NE, looking to NE .......................................................................... 35

Figure 10-1: Drilling evolution in time for Rosario Oeste .......................................................................................................... 37

Figure 10-2: Drilling evolution in time for Rosario ..................................................................................................................... 38

Figure 11-1: CuT results for STD-09-02. .................................................................................................................................. 43

Figure 11-2: RC CuT results for RC field duplicates. ............................................................................................................... 43

Figure 11-3: CuT results for RC field duplicates ....................................................................................................................... 44

Figure 11-4: CuT results for pulp duplicates. ............................................................................................................................ 45

Figure 13-1: Simplified flow sheet for mineral treatment at CMDIC .......................................................................................... 46

Figure 14-1: Rosario and Rosario Oeste "type-sections" used by Leapfrog to generate 3D geological models ...................... 51

Figure 14-2: Cross section N 77821: 4 m showing the mineralization model for Rosario Sur. ................................................. 53

Figure 14-3: Contact profile: total copper - primary and pyritic primary domains for Rosario ................................................... 55

Figure 14-4: Contact profile: total copper - secondary and primary domains for Rosario Oeste .............................................. 55

Figure 14-5: Correlogram map for total copper - primary sulphides in Rosario ....................................................................... 56

Figure 14-6: Correlogram model for total copper - primary sulphides in Rosario ..................................................................... 57

Figure 14-7: EW swath plot for total copper - Rosario secondary domain ............................................................................... 61

Figure 14-8: NS swath plot for total copper - Rosario Oeste secondary domain ...................................................................... 61

Figure 14-9: Historical reconciliation: tonnage 2004-2011 ....................................................................................................... 62

Figure 14-10: Historical reconciliation: CuT grade 2004-2011 ................................................................................................. 63

Figure 14-11: Historical reconciliation: fine copper 2004-2011 ................................................................................................. 63

Figure 14-12: EW section (N 78,445 ± 50m) showing the Ujina resource classification ........................................................... 67


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Figure 14-13: Plan view (elevation 4,150 ± 7.5m) showing the Rosario resource classification ............................................... 67

Figure 16-1: Slope Angles applied to Whittle optimizations of Rosario and Ujina. ................................................................... 76

Figure 16-2: Rosario Mining Phases ........................................................................................................................................ 78

Figure 16-3: Ujina Mining Phases ............................................................................................................................................ 78

Figure 21-1: Ujina mineral reserve calculation parameters ...................................................................................................... 85

Figure 21-2: Rosario mineral reserve calculation parameters .................................................................................................. 86

Figure 21-3: Yearly Capital Expenditure (CAPEX) ................................................................................................................... 87

Figure 24-1: Historical production for CMDIC's operating deposits .......................................................................................... 89


29 March 2012 Report No. 1292154001 9

1.0 SUMMARY 1.1 Scope Xstrata Copper (Xstrata) on behalf of Xstrata Canada Corporation commissioned Golder Associates S.A. (Golder) to review the December 31, 2011 Mineral Resource and Mineral Reserve estimates for the Collahuasi Copper Mine (Collahuasi) and prepare a Technical Report as defined in Canadian National Instrument 43-101, Standards of Disclosure for Mineral Projects.

Compañía Minera Doña Inés de Collahuasi (CMDIC) is owned by subsidiaries of Anglo American plc (44%), subsidiaries of Xstrata plc (44%) and a consortium of Japanese companies led by Mitsui & Co. Ltd. (12%).

CMDIC’s mining operations correspond to a cluster of open pit mines located in the Region I of Chile, about 225 km by road southeast of the city of Iquique. The office and camp sites are located at 3,800 meters above the sea level (m.a.s.l.). The pits and mill are located at elevations up to 5,000 m.a.s.l. The main mine in operation is the Rosario pit. Additional ore production is currently coming from the Capella oxide pits. The original pit where the operations started, Ujina, is not currently in production but is part of the Life Of Mine (LOM) plan.

The Mineral Resources and Mineral Reserves estimates dated December 31, 2011 were prepared by CMDIC’s personnel and were reviewed by a multidisciplinary team of qualified persons from Golder. The estimates were reviewed in detail including parameters, assumptions, supporting factual data, procedures and electronic files. Golder has carried out several data verification analysis on CMDIC’s geological database since 2007 and has reviewed reconciliation results between production data and the estimates.

This report and the mineral resources and mineral reserves estimates have been prepared in compliance with the disclosure and reporting requirements set forth in the current Canadian Securities Administrator’s National Instrument 43-101, Companion Policy 43-101CP, and Form 43-101F1.

The Effective Date of this Report is December 31, 2011 (“Effective Date”). This Technical Report discloses the results of an estimation update carried out by CMDIC as part of their annual planning cycle.


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1.2 Notes to the report All currency amounts are in United States dollars unless otherwise indicated. The abbreviations commonly used in this report are summarized below in Table 1-1.

Table 1-1: Abbreviations As Arsenic

BH Blast Hole

CMDIC Compañia Minera Doña Inés de Collahuasi

CuT Total copper

CuS Sulphuric acid soluble copper

DDH Diamond Drill Hole

BSE Base of Secondary Enrichment

EDA Exploratory Data Analysis

Jd3 Cubic yards

G&A General and Administration costs

Golder Golder Associates S.A.

ktpd 1,000 tonnes per day

l/s Litres per second

LOM Life of Mine

m Meters

m.a.s.l. Meters above sea level

Mt Million tonnes

Mtpa Million tons per annum

QAQC Quality Assurance and Quality Control

RC Reverse Circulation Drill Hole

tpd Tonnes per day

µm Microns

t Metric tonne


29 March 2012 Report No. 1292154001 11

1.3 Property description and ownership CMDIC is located in the Tarapacá Region of Chile, in the Andean cordillera, approximately 5 to 10 km from the border with Bolivia, 185 km SE of Iquique at elevations between 4,200 and 4,800 m.a.s.l. The mining project is allocated in an area of approximately 16,669 hectares. Additional 88,269 hectares are used for industrial infrastructure location, port facilities and sites of hydrogeological interest among others. The reported mineral resources and mineral reserves are located within CMDIC’s mining concessions. CMDIC holds all the necessary permits, licences and title deeds required by Chilean law.

CMDIC is owned by subsidiaries of Anglo American plc (44%), subsidiaries of Xstrata plc (44%) and a consortium of Japanese companies led by Mitsui & Co. Ltd. (12%).

1.4 Geology and mineralization CMDIC is a world class cluster of porphyry copper deposits with high sulphidation epithermal overprinting and significant structural control at the Rosario system. Rosario, Rosario Oeste and Ujina are the major deposits, consisting of primary and secondary enriched sulphides and oxides. A series of small oxide deposits are located to the west (Capella) and south (Rosario Sur) of Rosario. Copper sulphide mineralization is mainly represented by chalcocite, chalcopyrite and bornite. Oxide mineralisation occurs mainly as chrysocolla with minor brochantite, native copper, and copper-iron-manganese oxides and hydroxides.

1.5 Status of exploration Since the start of the operations at Collahuasi, CMDIC has carried out infill drilling campaigns aimed at updating resource classification as well as exploration drilling to expand its resource base. Near pit exploration has been successful in expanding the mineral resources over the years. Additional exploration campaigns have been implemented based on geophysical methods.

1.6 Development and operations The feasibility and environmental impact studies for the Collahuasi project were approved in 1995 and, at the end of 1996 and once financing and marketing agreements had been signed, the development and construction phase began.

Mineral processing at CMDIC commenced in 1998 with the exploitation of the Ujina deposit at an average daily treatment rate of 60 ktpd. In 2004 the operation was expanded to 110 ktpd based on a new deposit named Rosario. Currently, the nominal mineral processing capacity for the concentrator line is 150 ktpd, which has been achieved after geometallurgical and process engineering studies were performed aimed at maximizing the use of the available assets in the treatment plant (debottlenecking).

CMDIC processes two different material types: sulphides and oxides which are sent to two independent processing plants. Two major open pit operations (Rosario and Ujina) are the source of sulphide material while the oxides come from the smaller pits Capella Este and Sur. The main product is copper concentrate which accounts for 90% of the copper produced; the other 10% correspond to cathodes.

The planned sulphide concentrator feed is approximately 150 ktpd for 2012 and 2013, and 160 ktpd from 2014 onwards. The disclosed sulphide mineral reserves above 0.30% CuT are sufficient to sustain plant feed for approximately 49 years (since 2012). According to current oxide reserves and considering the planned production rate of 25 ktpd, leaching and SX-EW production will continue until 2017.


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1.7 Mineral resource and mineral reserve estimates The geological models supporting resource estimation at Collahuasi include a total of 8 independent block models. Each block model was estimated using established geostatistical techniques following comprehensive statistical data analysis.

The evaluation of appropriate geological groupings into estimation domains was undertaken through the iterative definition of grade populations for each element using spatially declustered statistics. Spatial data analysis was then performed to derive correlogram models for each estimation domain.

The block grade estimates include total copper, soluble copper, molybdenum and arsenic. Grade estimation was carried out on variable block sizes using Ordinary Kriging (OK) for most estimation domains. Multiple estimation passes were defined reflecting the ranges established by the correlogram models. Once the grade estimation had been performed and validated, the models were re-blocked to a regular block size for the purpose of mine planning.

Dr. Marcelo Godoy, MAusIMM (CP) and Principal Geostatistician and Mining Engineer with Golder has reviewed, verified and takes responsibility for the December 31, 2011 Resource Estimation Update of the Collahuasi Mineral Resources. Dr. Godoy is a qualified person and independent for the purposes of National Instrument 43-101.

Mineral resources quoted are inclusive of reported mineral reserves. No modifying factors have been applied to the mineral resource data. Mineral resources are estimated and reported on 100% basis. All tonnages are reported on a dry basis. Table 1-2, Table 1-3, Table 1-4 and Table 1-5 summarize the mineral resource figures for Rosario, Rosario Oeste, Ujina and the oxide deposits (Capella Sur & Este and Rosario Sur) respectively. Table 1-6 summarizes the total Mineral Resources for Collahuasi.

Table 1-2: CMDIC Mineral Resources for the Rosario deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.4 %CuT) Indicated kt 3 0.67 Inferred kt 2,108 0.49

Mixed (Cut-off: 0.5 %CuT) Measured kt 16 0.60 Indicated kt 40 0.52 Inferred kt 15 0.54

Sulphides (Cut-off: 0.3 %CuT) Measured Mt 267 0.99 Indicated Mt 2,251 0.86 Inferred Mt 1,462 0.85

Table 1-3: CMDIC Mineral Resources for the Rosario Oeste deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.4 %CuT) Inferred kt 1,351 0.60 Sulphides (Cut-off: 0.3 %CuT) Inferred Mt 1,683 0.77


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Table 1-4: CMDIC Mineral Resources for the Ujina deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.3 %CuT) Indicated kt 153 0.92 Inferred kt 505 0.85


Sulphides (Cut-off: 0.3 %CuT) Measured Mt 112 0.76 Indicated Mt 879 0.64 Inferred Mt 776 0.62

Table 1-5: CMDIC Mineral Resources for the oxide deposits as at 31 December 2011 Deposit Classification Unit Tonnage Grade (%CuT)

Capella Sur & Este (Cut-off: 0.3%Tcu) Indicated Mt 6 0.68

Rosario Sur (Cut-off: 0.25%Tcu) Measured Mt 33 0.60 Indicated Mt 5 0.57 Inferred Mt 1 0.47

Table 1-6: CMDIC Total Mineral Resources as at 31 December 2011

Resource Category Sulphide Oxide and Mixed

Tonnage (Mt) Grade (%CuT) Tonnage (Mt) Grade (%CuT)

Measured 378 0.92 33 0.60

Indicated 3,266 0.79 16 0.67

Measured + Indicated 3,644 0.80 49 0.62

Inferred 3,900 0.80 5 0.60

Important information regarding the mineral resources disclosed in the tables above:

The Measured and Indicated Mineral Resources are inclusive of those Mineral Resources modified to produce the Mineral Reserves.

Mineral Resources are enclosed within pit shells that were optimized using Measured, Indicated and Inferred resources at a copper price of US$ 2.80/lb.

Mineral Resource tonnages have been rounded to reflect the accuracy of the estimate, and numbers may not add due to rounding.

For the estimation of mineral reserves an industry standard methodology consisting on pit optimization, mine sequencing, cut-off grade optimization and production scheduling was applied.


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Economic pit limits were calculated using Gemcom’s Whittle 4X software. This software applies the Lerchs-Grossmann algorithm for the definition of ultimate pit limits. A series of nested pits is constructed for a given series of copper prices (or revenue factors). The economic extraction sequence was established following the physical advances of the nested pits. Operational designs of mining cutbacks were performed with Maptek’s Vulcan software.

An optimized cut-off grade strategy was calculated using COMET software. This software applies K. Lane’s logic to include time discount factors into the estimation of the cut-off grades per period. The logic was used for simultaneous optimisation of cutback sequence and cut-off grade policy for the life of mine. The algorithm uses a Net Present Value (NPV) objective function to modify the operating policies and maximise the NPV. Since NPV is derived from the discounted cash flows, the cash flow calculation must accurately reflect cost and revenue drivers. Constraints on the schedule also play a key role in ensuring that only valid operating policies are considered. Constraints normally include equipment (e.g. restrictions on truck assignment and maximum movement per cutback), geometry, access (sinking rates) and process capacities (conveyor limits, SAG time, recovery and concentrate grades).

Mr. Juan Pablo Gonzalez, Registered Member of the Chilean Mining Commission and Senior Mining Engineer with Golder has reviewed, verified and takes responsibility for the December 31, 2011 Estimation Update of the Collahuasi Mineral Reserves. Mr. Juan Pablo is a qualified person and independent for the purposes of National Instrument 43-101.

The QP considers that the conversion of the Mineral Resources into Mineral Reserves was based on appropriate mine design and planning. In particular, dilution and mine recovery are supported by historical data. The tonnes and grades are reported at appropriate economic cut-off grades based on documented costs and prices.

The numbers have been checked and are considered to be appropriate for the purpose of public reporting in that the mineral reserves provide an acceptable prediction of the available material expected from mining. The mineral reserves disclosed for the CMDIC operation include only mineralization classified as Measured and Indicated Resources and are presented in Table 1-7, Table 1-8 and Table 1-9. Reserves included in stocks are presented in Table 1-10. The figures are provided at the appropriate level of precision and comply with all disclosure requirements for mineral reserves set out in the National Instrument 43-101. Table 1-11 summarizes all Mineral Reserves for CMDIC.

Table 1-7: CMDIC Mineral Reserves for the Rosario deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.4 %CuT) Probable kt 3 0.67

Mixed (Cut-off: 0.5 %CuT) Proven kt 16 0.60

Probable kt 40 0.52

Sulphides (Cut-off: 0.3 %CuT) Proven Mt 211 1.13

Probable Mt 1,694 0.84


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Table 1-8: CMDIC Mineral Reserves for the Ujina deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.3 %CuT) Probable kt 153 0.92 Mixed (Cut-off: 0.5 %CuT) Probable kt 157 1.78

Sulphides (Cut-off: 0.3 %CuT) Proven Mt 74 0.90 Probable Mt 746 0.64

Table 1-9: CMDIC Mineral Reserves for the Oxide deposits as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Capella Sur & Este (Cut-off: 0.3%CuT) Probable Mt 6 0.68

Rosario Sur (Cut-off: 0.25%CuT) Proven Mt 21 0.59 Probable Mt 4 0.57

Table 1-10: CMDIC Mineral Reserves in Stocks as at 31 December 2011 Material type Classification Unit Tonnage Grade (% CuT)

Oxides (in-stock) (Cut-off: 0.3%CuT) Probable Mt 3 0.72 Mixed (in-stock) (Cut-off: 0.5 %CuT) Probable Mt 2 0.83 Sulphides (in-stock) (Cutoff: 0.4%CuT) Probable Mt 135 0.61

Table 1-11: CMDIC Total Mineral Reserves as at 31 December 2011

Reserve Category Sulphide Oxide and Mixed

Tonnage (Mt) Grade (%CuT) Tonnage (Mt) Grade (%CuT)

Proven 285 1.07 21 0.59

Probable 2,575 0.77 15 0.69

Proven + Probable 2,860 0.80 35 0.63

To the QP’s knowledge, there are no known environmental, permitting, legal, title, taxation, socioeconomic, marketing, political, or other relevant issues which may materially affect the mineral reserves estimates stated above.


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1.8 Conclusions and recommendations The following is a list of general conclusions:

The geology is well understood for the CMDIC copper deposits. The copper and molybdenum mineralization types and extents are well defined, and that knowledge has been integrated into the block models, mining practice and metallurgy.

The quality of the assay data used for block model grade estimates is supported by years of good to excellent reconciliation of material milled to block model grades and tonnages.

The block models were developed using industry-accepted methods.

The Mineral Reserve at CMDIC falls completely within the classification of Proven and Probable Mineral Reserves.

The cut-off grade strategy employed by CMDIC is based on industry-accepted parameters.

Metallurgical expectations are reasonable and based on metallurgical results obtained during production. The increase in production capacity that is considered to take the concentrator from 140ktpd to 160ktpd starting in 2014 is achievable and CMDIC has done considerable amount of process engineering work to support this increase.

Operating cost estimates are reasonable and have been calculated using sound industry-accepted practices with a great deal of input from the ongoing operation.

The assumptions used for cost and revenue estimation are within industry parameters and are valid assumptions for an economic forecast.

Golder considers that the December 31, 2011 mineral resources and mineral reserves estimates for CMDIC have been prepared in compliance with the disclosure and reporting requirements set forth in the current Canadian Securities Administrator’s National Instrument 43-101 and Companion Policy 43-101CP.


29 March 2012 Report No. 1292154001 17

2.0 INTRODUCTION Xstrata Copper (Xstrata) on behalf of Xstrata Canada Corporation commissioned Golder Associates S.A. (Golder) to review the December 31, 2011 Mineral Resource and Mineral Reserve estimates for the Collahuasi Copper Mine (Collahuasi) and prepare a Technical Report as defined in Canadian National Instrument 43-101, Standards of Disclosure for Mineral Projects.

Compañía Minera Doña Inés de Collahuasi (CMDIC) is owned by subsidiaries of Anglo American plc (44%), subsidiaries of Xstrata plc (44%) and a consortium of Japanese companies led by Mitsui & Co. Ltd. (12%).

CMDIC’s mining operations correspond to a cluster of open pit mines located in the Region I of Chile, about 225 km by road southeast of the city of Iquique. The pits and processing plants are located at elevations up to 5,000 meters above the sea level (m.a.s.l.). Currently, the main operating mine is the Rosario pit. Additional ore is currently coming from the Capella oxide pits. The original pit where the operations started, Ujina, is not currently in production but is part of the Life Of Mine (LOM) plan.

The mineral resources and mineral reserves estimates were prepared CMDIC’s personnel and were reviewed and validated by a multidisciplinary team of QPs from Golder. The estimates were reviewed in detail including parameters, assumptions, supporting factual data, procedures and electronic files. Golder has carried out several data verification analysis on CMDIC’s geological database since 2007 and has reviewed reconciliation results between production data and the estimates.

This report and the mineral resources and mineral reserves estimates have been prepared in compliance with the disclosure and reporting requirements set forth in the current Canadian Securities Administrator’s National Instrument 43-101, Companion Policy 43-101CP, and Form 43-101F1.

The following professionals served as the Qualified Persons (QPs) as defined in National Instrument 43-101, Standards of Disclosure for Mineral Projects, and in compliance with Form 43-101F1. The QPs responsible for the preparation of the Report are:

Marcelo Godoy, PhD, Principal Geostatistician and Mining Engineer with Golder Associates S.A. and Member of the AusIMM (CP) was responsible for the overall preparation of the report and is supervised the preparation of Sections 1 to 6, 13, 14, 19, 20, 24 to 27 of this report. Dr. Godoy visited the property from 3 to 7 December 2007.

Ronald Turner, Senior Resource Geologist with Golder Associates S.A. and Member of the AusIMM (CP) was responsible for review and preparation of Sections 7 to 12 of this report. Mr Turner visited the property from 27 to 28 January 2010.

Juan Pablo Gonzalez, Senior Mining Engineer with Golder Associates S.A. and Registered Member of the Chilean Mining Commission was responsible for the preparation of Sections 15 to 18, 21 and 22 of this report. Mr Gonzalez visited the property from 3 to 7 December 2007.

In preparing this report, Golder has relied on various reports, maps and technical papers listed in the References section at the conclusion of this report and on experience gained from similar deposits.

All measurement units used in this Report are metric, and currency is expressed in US dollars unless stated otherwise.


29 March 2012 Report No. 1292154001 18

3.0 RELIANCE ON OTHER EXPERTS The qualified persons have relied on the information, opinions and statements of other experts that are not qualified persons. Such reliance encompasses information concerning mineral processing, infrastructure, legal, environmental and political issues. All reasonable endeavours have been made to ensure the accuracy and reasonableness of the information supplied by other experts. No warranty or guarantee, be it express or implied, is made by Golder with respect to the completeness or accuracy of such information provided.


29 March 2012 Report No. 1292154001 19

4.0 PROPERTY DESCRIPTION AND LOCATION 4.1 Location CMDIC is located in the Tarapacá Region of Chile (Figure 4-1), in the Andean cordillera, approximately 5 to 10 km from the border with Bolivia, 185 km SE of Iquique at elevations between 4,200 and 4,800 m.a.s.l.

Figure 4-1: CMDIC location map

4.2 Claim status The mining project is allocated in an area of approximately 16,669 hectares. Additional 88,269 hectares are used for industrial infrastructure, port facilities and sites of hydrogeological interest.

The reported mineral resources and mineral reserves are located within CMDIC’s mining concessions (Figure 4-2). CMDIC holds all the necessary permits, licences and title deeds required by Chilean law.

The CMDIC mining concessions are composed by the following areas: Alfa; América 1 to 3; Ana 1 to 3; Bambino 1 to 377; Bamby 1 to 308; Bélgica 1 to 152; Bermudas 1 to 150; Beta; Birmania 1 to 150; Brasil 1 to 225; Bulgaria 1 to 364; Canadá 1 to 180; Ceilán 1 to 180; Cinco; Cominco 1 to 284; Cuatro; Delta; Dos; Gama; Huinquintipa 1 to 20; Huinquintipa 31 to 36; Huinquintipa 37 to 43; Huinquintipa 21 to 30; Lama; María Angélica Segunda 1 to 1864; María Paz 1 to 864; Rogelia 1 to 3; Seis; Siria 1 to 200; Somalía 1 to 200; Tres; Uno y Zeta. Figure 4-2 shows the general layout of CMDIC’s mining claims. The mining concessions for these areas have been granted on 20 December 2001. Table 4-1 describes the surface for each mining concession.

To the knowledge of the authors, the mining concessions listed above are in good standing and constitute all of the mineral rights that are required to permit exploitation of the deposit for which mineral reserves and mineral resources are being stated in this report.


29 March 2012 Report No. 1292154001 20

Figure 4-2: CMDIC mining property layout

Table 4-1: Concession name and surface Concession name Surface (Ha)

ALEMANIA 1/10 10 ARGELIA 1/448 448 AUSTRIA 1/391 782 ALBANIA 1/413 702 BULGARIA 1/364 725 BRASIL 1/225 363 BAHAMAS 1/150 750 BIRMANIA 1/150 750 BERMUDAS 1/150 750 BELGICA 1/152 760


29 March 2012 Report No. 1292154001 21

Concession name Surface (Ha)

CANADA 1/180 900 CEILAN 1/180 900 COREA 1/180 900 CHINA 1/180 900 SALVADOR 1/194 970 SIRIA 1/200 1000 SOMALIA 1/200 1000 SUIZA 1/200 1000 SUMATRA 1/200 1000 SUECIA 1/192 960 TOTAL 15.57

4.2.1 Surface and camps rights CMDIC is the owner of 79 groups of superficial rights that cover a surface of 15,293.626 hectares. These rights covers the areas of the Ujina, Rosario and Capella deposits, the tailings storage facility, the current mine infrastructure, the evaporation and forestation pools, the port area, the dissipation stations for the concentrate pipeline and other areas that relate to water extraction areas in Huasco and Quebrada Caya. These areas are located within the municipalities of Pica and Pozo Almonte and their exact surfaces are described in Table 4-2.

Table 4-2: Surfaces for CMDIC infrastructure and mine lots

Sector Surfaces

Ha Mine area 14,191.28

Evaporation and forestation pools 225.30

Port area 112.40

Dissipation stations for concentrate pipeline 10.31

Huasco area 223.00

Quebrada Caya area 531.40

CMDIC also rents 4 state owned areas that cover a surface of 5.01 hectares. Telecommunication installations for the project operation (transmission antennae and all complementary equipment) are located within these areas.


29 March 2012 Report No. 1292154001 22

4.2.2 Water rights and right of way Water rights a) CMDIC owns underground water consumption rights, both permanent and continuous, for a total flow of

263.5 l/s to be extracted from the Michincha Salar basin which is located in the Michincha Pampa sector, municipality of Pica, Tamarugal Province in the Tarapacá Region.

b) CMDIC owns several rights to use underground water in the Coposa Salar basin, municipality of Pica. The total flow from this basin is of 1,041 l/s. Part of these rights were granted as permanent and definitive (867 l/s) and the rest as provisional rights (174 l/s).

Right of way CMDIC has processed and constituted in favor of its dominant tenement (mining concessions and surface property rights) and the treatment plants located in the Ujina sector, a series of mining easements (rights of way and water rights), with a total surface of 29,276 hectares. These surfaces are used to place concentrate and water pipelines, electric lines, access roads. These easements are processed according to articles 120 and 121 of the Chilean Mining Code. Some of these easements have been processed at the Ministry of National Assets (Ministerio de Bienes Nacionales) and the other at regional courts in the Tarapacá and Antofagasta regions. Some of the properties that are part of these easements will subsequently be bought from the government of Chile.

Considering that the concentrate pipeline crosses mining easements from other companies it was necessary to subscribe individual easement contracts with them. In the same manner, it was necessary to subscribe an easement contract with Empresa de Transportes Ferroviarios S.A. to allow the concentrate pipeline to pass through properties which are owned by the company.

4.3 Property boundaries and location of mineralized zones The property boundaries were located based on extensive surface mapping and geophysical survey, identifying the extent of the mineralized areas. Condemnation drilling was also conducted to define facilities sites.

CMDIC owns 546 groups of mining exploration concessions that cover an area of 143,008 hectares. It is also entitled to 371 mining exploration concessions that cover an extra 143,300 hectares. However, only 20 groups of mining concessions, with an area of 15,570 hectares, cover the zones where mineral resources and mineral reserves are defined. The UTM coordinates for the polygon in which these 20 groups of concessions are located are described in Table 4-3.

Table 4-3: UTM coordinates for the property containing mineral resources and mineral reserves Vertices North UTM (m) East UTM (m)

1 7,684,500.00 522,700.00 2 7,684,500.00 540,000.00 3 7,672,000.00 540,000.00 4 7,672,000.00 522,700.00


29 March 2012 Report No. 1292154001 23

Rosario, Ujina and Rosario Oeste are the main sources of mineral resources and mineral reserves for CMDIC and include mainly copper sulphide mineralization. There are also small copper oxide bodies within the mining properties, highlighting Rosario Sur and other oxide copper bodies known as "Capella". Figure 4-3 is a satellite image showing the area of operations including the open pits, the tailings storage facility, the waste dumps, the concentrator, the leach pads and the SX-EW plant.

Figure 4-3: CMDIC mining operation layout

4.4 Nature and extent of issuers title CMDIC is owned by subsidiaries of Anglo American plc (44%), subsidiaries of Xstrata plc (44%) and a consortium of Japanese companies led by Mitsui & Co. Ltd. (12%).

4.5 Environmental liabilities The CMDIC project commenced with the initial environmental permit approval issued in 1995. An Environmental Impact Study (EIS) was subsequently submitted for the first expansion to 110 ktpd and approved in 2001. Following that expansion, CMDIC submitted an EIS for the transmission line and substation which was approved in 2003. Since that time a number of Environmental Impact Declarations have been approved for additional changes to the project including energy supply, process modifications, exploration activities, camp expansion and the optimization project to expand production to 170 ktpd which was approved in 2010.


29 March 2012 Report No. 1292154001 24

4.6 Future work CMDIC’s strategic plan of growth aims at reaching a copper production rate of approximately 1 Mtpa by 2020, based on a portfolio of projects for both production lines (concentrate and cathodes). Figure 4-4 summarizes the growth strategy for CMDIC in terms of production rates. Following is a description of the projects that will allow CMDIC to reach the future production plans:

4.6.1 Growth projects for the concentrate line: Phase I: contemplated rising the treatment rate from 126 ktpd to 150 ktpd, by means of releasing bottlenecks from the system. This project has already been implemented.

Phase II: continuing the bottleneck liberation to increase from 150 ktpd to a maximum of 160 to 200 ktpd, depending on the bottleneck liberation conditions. The current LOM considers achieving a rate of 160 ktpd by 2014. This stage is currently in development.

Phase III: an expansion project that considers the incorporation of 1 or 2 grinding lines with a capacity of 110 ktpd each, aiming at reaching a production levels between 800 ktpa to 1000 ktpa of Cu concentrate.

4.6.2 Growth projects for the cathodes line: Phase I: contemplates reaching full capacity of the current SW-EW plant via liberation of bottlenecks, to reach production levels between 90 to 110 ktpa of cathodes. Currently this project is at scoping level.

Phase II: contemplates expanding the current capacity of the SW-EW plant, in order to align the life span of the project with the concentrator line, reaching cathode production levels over 200 ktpa. This project is currently in a pre-scoping stage.

Figure 4-4: Summary of CMDIC's growth strategy


29 March 2012 Report No. 1292154001 25

5.0 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY

5.1 Accessibility CMDIC’s mining activities are located approximately 185 km to south east of Iquique in Northern Chile at elevations between 4,200 and 4,800 m.a.s.l. Access to the mine is via a main paved road from Iquique and can be done in approximately 3 hours by car.

5.2 Climate and physiography The climate is typical of the high Andes, with temperatures rarely exceeding 10 degrees Celsius and reaching below -20 degrees Celsius. Major climatic events that affect mining operations are the summer rains (December to February) and snowfall in winter.

The production plan contemplates a maximum material movement of 270 Mtpa, considering an operation of 360 days (5 days are discounted for weather conditions). The concentrator considers 365 days of operation per year.

5.3 Infrastructure and camp facilities CMDIC is an operating mine. The mine site facilities include three open pits (Ujina, Rosario and Capella), an oxide treatment plant, sulphide concentrator and comprehensive infrastructure including a permanent camp. The open pits, together with the facilities at the mine site, are at elevations that range from 3,800 to 4,500 m.a.s.l.

The complex also includes two concentrate slurry pipelines with 203 km in length and diameters of 8” and 7”. The port facilities, including the molybdenum recovery plant, copper concentrate filter plant, concentrate storage facilities and marine terminal are located at Punta Patache which is approximately 80 km south of Iquique. The filter plant is nominally at sea level.

6.0 HISTORY Commercial activity in the CMDIC mining district dates back to 1880 when its systems of high-grade copper and silver veins began to be exploited. These operations continued for fifty years until their interruption by the Great Depression. Work in the area resumed in 1978 with the identification of the key components of the Rosario deposit. A series of satellite, aerophotogrametric and onsite studies followed, along with drilling activities, and in 1991 the Ujina deposit was discovered.

The feasibility and environmental impact studies for the Collahuasi project were approved in 1995. At the end of 1996, once financing and marketing agreements had been signed, the construction phase began.

Mineral processing at CMDIC commenced in 1998 exploiting the Ujina deposit at an average treatment rate of 60 ktpd. In 2004 the operation was expanded to 110 ktpd based on a new deposit named Rosario. Currently, the installed nominal mineral processing capacity is 150 ktpd.


29 March 2012 Report No. 1292154001 26

7.0 GEOLOGICAL SETTING AND MINERALIZATION 7.1 Regional geology CMDIC is a cluster of porphyry copper deposits with high sulphidation epithermal overprinting and significant structural control at the Rosario system. Rosario, Rosario Oeste and Ujina are the major deposits, consisting of primary and secondary enriched sulphides and oxides. A series of small exotic oxide deposits are located to the west (Capella) and south (Rosario Sur) of Rosario. Copper sulphide mineralization is mainly represented by chalcocite, chalcopyrite and bornite. Oxide mineralisation occurs mainly as chrysocolla with minor brochantite, native copper, and copper-iron-manganese oxides and hydroxides.

CMDIC forms part of the cluster that includes several porphyry Cu-Mo and Cu vein deposits, from east to west are: Ujina, Rosario and Quebrada Blanca as shown in Figure 7-2. This cluster is part of the NS Tertiary porphyry belt, controlled by the north-south trending West Fissure fault system. This system controls many of the world-class Chilean porphyry copper deposits, such as Escondida, Chuquicamata and El Abra, see Figure 7-1.


29 March 2012 Report No. 1292154001 27

Figure 7-1: Regional schematic showing the Eocene-Oligocene porphyry copper belt.

Taltal

22 º S

24º S

26º S

70º W

100 km Bolivia

Argentina

Paci

ficO

cean

Antofagasta

Vn. Lascar

Vn. Socompa

Vn. Llullaillaco

El Salvador

La Escondida

Zaldivar Escondida Norte

Chuquicamata

El Abra

QuebradaBlanca

Collahuasi

PotrerillosM odified from Richards, et al., 2001

Chile

Eocene-OligocenePorphyry Belt

Domeyko Fault System

Atacama Fault System

Calama

Taltal

22 º S

24º S

26º S

70º W

100 km Bolivia

Argentina

Paci

ficO

cean

Antofagasta

Vn. Lascar

Vn. Socompa

Vn. Llullaillaco

El Salvador

La Escondida


Chuquicamata

El Abra

QuebradaBlanca

Collahuasi


Chile




Taltal

22 º S

24º S

26º S

70º W

100 km100 km Bolivia

Argentina

Paci

ficO

cean

Antofagasta

Vn. Lascar

Vn. Socompa

Vn. Llullaillaco

Vn. Lascar

Vn. Socompa

Vn. Llullaillaco

El Salvador

La Escondida


Chuquicamata

El Abra

QuebradaBlanca

Collahuasi

Potrerillos

El Salvador

La Escondida


Chuquicamata

El Abra

QuebradaBlanca

Collahuasi


Chile







Calama


29 March 2012 Report No. 1292154001 28

Figure 7-2: Regional schematic W-E geological section of the CMDIC district showing the distribution of the major

mineralised systems.

CMDIC is situated within a Permo-Triassic uplifted block that is limited to the east by the Loa fault and to the west by the Domeyko fault, which is part of the West Fissure system. The host rocks in the area are continental to shallow marine volcanic and sedimentary rocks of the Permo-Triassic Collahuasi Formation. It is overlaid unconformable by the Jurassic Quehuita Formation, which is composed of a folded sequence of deep to shallow marine sedimentary rocks, and by the Cretaceous Cerro Empexa Formation, which is composed of continental volcano-sedimentary rocks. Collahuasi is intruded by a series of granitic plutons dated as Permian (231 to 262 Ma). The oldest portion of the volcanic sequence is Permian or older, supported by new age dates collected from rhyodacite units (Masterman, 2003). The mineralisation at CMDIC is related to various Permian to Oligocene porphyry intrusives, including the Ines porphyry, the Collahuasi porphyry, the Rosario porphyry and the Inca porphyry. In the northern part of the district, a thick Cenozoic ignimbrite covers most of this basement (Masterman, et al,. 2004; Masterman, et al,. 2005).

Tertiary tectonic movements associated to the West Fissure system caused the development of conjugated set of NW-NE faults. These faults acted as controls to the intrusion of porphyries associated to Rosario and Ujina deposits. Figure 7-3 shows a schematic geological map of the Collahuasi district.

Structures has special significance because their control in the distribution of mineralisation and lithologies in Rosario Oeste. The main structures are NE. There are other two NW and NNW structural guidelines which are associated to the NE according to the model proposed transcurrente.


29 March 2012 Report No. 1292154001 29

Figure 7-3: District schematic geology for the Collahuasi area.

7.2 Local geology 7.2.1 Mineralisation Mineralisation at Rosario and Ujina is mainly associated with veins, especially in Rosario. These major Cu-Ag-As veins include the NNE trending Montezuma and La Grande vein systems and the NW-trending Rosario and Poderosa vein systems (Masterman, et al,. 2005). The two deposits show typical profile of a secondary enrichment process: a leach cap, a copper oxides zone, a secondary enrichment blanket and a primary sulphide core. To the west of Rosario is located Capella, which is an exotic copper deposit with copper oxides associated to gravels, probably derived from the Rosario porphyry.

The Rosario deposit is characterized by a dome-shaped zone of copper mineralization centred on the Rosario and Collahuasi porphyries (see Figure 7-4). The centre of the mineralised zone contains bornite, chalcopyrite, and primary chalcocite and generally lacks pyrite. Copper mineralization occurs as both disseminations and fracture-controlled veinlets. The deposit contains a thin, erratically developed secondary enrichment blanket underlain by a relatively high-grade primary chalcopyrite zone. The lack of a well-developed secondary enrichment blanket is due to both presence of structures and level of oxidization. In addition, the secondary zone is offset and developed along crosscutting faults, resulting in erratic and locally deep oxidization. Oxide mineralisation is concentrated mostly in the northeast portion of the deposit. The oxide consists of chrysocolla, malachite and brochantite in a strongly limonitic matrix. Cuprite, tenorite and native Cu are also locally present.

Chile

Bolivia

Rosario

ProfundaUjinaQuebrada

Blanca

EW

0 20km

E-W X-Section

N

Modified from L.A.Dick (1994)

Tertiary

Permian

Jurassic

Volcanic Rocks

Sedimentary Rocks

Intrusive andVolcanic Rocks

Porphyry Deposits

Faults

LEGEND

West Fissure Loa Fault

Recent Volcanoes

Chile

Bolivia

Rosario

ProfundaUjinaQuebrada

Blanca

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N

Modified from L.A.Dick (1994)

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Permian

Jurassic

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Sedimentary Rocks

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Porphyry Deposits

Faults

LEGEND

West Fissure Loa Fault

Recent Volcanoes


29 March 2012 Report No. 1292154001 30

At Ujina the hypogene mineralization is spatially related to the Ujina porphyry (see Figure 7-5). It s associated to a low sulphide core with chalcopyrite and pyrite, that grades outward to a pyritic shell. The high grade zones correspond to the contact between Ujina and Collahuasi porphyries. Deep oxidization has produced significant tonnages of secondary enriched copper sulphide and oxide minerals that overlie the primary chalcopyrite material.

Molybdenite is found within the primary hypogene mineralisation zone, peripheral to the Rosario porphyry. Molybdenum is enriched at depth, where grades are above 0.03% Mo. Molybdenum mineralization is predominantly restricted to within quartz veins with no significant alteration halo.

Mineralisation at Rosario Oeste denotes two major episodes of hypogene mineralization both responsible for extensive volumes of rock with copper and molybdenum mineralization type "porphyry copper". These events are represented by high sulphidation "veins" with copper mineralization - (arsenic (Silver - Gold). The spatial distribution of the mineralisation is controlled by movement of structural blocks. Events of secondary enrichment occur along structures and lithological horizons.

Figure 7-4: Typical mineralisation cross section of Rosario at 20NE, looking to NW

4,000m asl

4,400m asl

LIX

CP-BN

BN-CP

PRIPYCP-PY

MIX

0 100m0 100m

OXISEC SECP

SECDP SECD

Secondary PrimaryLeach & Oxide

2028 PitRosa

rio F

ault

Zone


29 March 2012 Report No. 1292154001 31

Figure 7-5: Typical mineralisation cross section of Ujina at 128NE, looking to NE

In Capella Sur, the gravels thicken to 30 to 40 metres depth and are intercalated with clay horizons rich in copper and manganese. Copper wad predominates in this mineralised body and only minor chrysocolla is found. Mineralisation at Capella Sur is lower grade and extends deeper into the basement rocks.

At Capella Este the copper mineralised zones deepen into basement rock forming a more voluminous mineralized zone with dimensions of 550 by 550 metres at depths between 45 and 120 metres below surface. The host rocks include acid volcanics as well as volcaniclastic and calcareous sedimentary sequences. Mineralisation occurs as chrysocolla, copper wad with some minor chalcocite and cuprite. It is unclear whether the Capella Este deposit is of exotic origin or whether it represents in-situ oxidation of weakly enriched sulphides.

7.2.2 Lithology The Rosario deposit is hosted within the La Grande unit, which formed the lower sequence of the Collahuasi formation. The La Grande unit is approximately 2,700 m thick and comprises of interbedded rhyolite, rhyodacite, dacite and andesite. The unit strikes NW and dips from 20 to 45 degrees NE. Andesites thin to the southwest across the Rosario deposit and the sequence become dominated by rhyolite. Volcaniclastic rocks and limestones of the Capella Unit, approximately 1,700 m thick, overlie the La Grande Unit on the northeaster side of the Rosario deposit. The rhyolitic Condor Unit outcrops to the west of the Rosario deposit. Both the Capella and Condor units are considered to have Triassic or Jurassic ages (Münchmeyer, et al, 1984). Emplacement of the porphyries appears to have been controlled by the Rosario fault system resulting in a north-westerly trend to

Section 128NE Looking NEcp>>pycp>py

py>cp py>>cp

4,000m asl

4,400m asl

75% -100%cp ± bn

50% -75% 25% -50%0% -25%

EnrichmentBlanket

Hypogene Zone

0 100m

FRH

LIX

OXIL

OXI

MIX OXI + SEC

SECA >75%cc,cv >1%Cu

SECB >75%cc,cv, <1%Cu

SECD <75%cc,cv, <10% PRI

SECPA >75%py,cc,cv, >1%Cu

SECPB >75%py,cc,cv, <1%Cu

PRI <75%py, 0-10% cc,cv

PRIPY >75%py, 0-10% cc,cv

2004 Pit

Section 128NE Looking NEcp>>pycp>py

py>cp py>>cp

4,000m asl

4,400m asl

75% -100%cp ± bn

50% -75% 25% -50%0% -25%

EnrichmentBlanket

Hypogene Zone

0 100mcp>>pycp>py

py>cp py>>cp

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50% -75% 25% -50%0% -25%

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0 100mcp>>pycp>py

py>cp py>>cp

cp>>pycp>py

py>cp py>>cp

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50% -75% 25% -50%0% -25% 75% -100%cp ± bn

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0 100m0 100m

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LIX

OXIL

OXI

MIX OXI + SEC

SECA >75%cc,cv >1%Cu

SECB >75%cc,cv, <1%Cu

SECD <75%cc,cv, <10% PRI

SECPA >75%py,cc,cv, >1%Cu

SECPB >75%py,cc,cv, <1%Cu

PRI <75%py, 0-10% cc,cv

PRIPY >75%py, 0-10% cc,cv

2004 Pit


29 March 2012 Report No. 1292154001 32

both porphyries. The Rosario fault system also acted as a control to the overprinting highsulphidation, massive Cu-Ag vein, which crosscuts the porphyry mineralisation at Rosario

Two major porphyries intrude Rosario, the Collahuasi porphyry and the Rosario porphyry (see Figure 7-6). Collahuasi porphyry has a granodioritic composition, and is between 50 to 300 m wide and up to 100 m long. Masterman (2003) suggests that this porphyry is Permian, with a U-Pb age of 245 Ma ± 12 Ma. Intruding the Collahuasi porphyry is the Rosario porphyry, which is 300 to 500 m wide and up to 1,500 m long. The Rosario porphyry has a 40Ar/39Ar age of 34.4 Ma ± 0.3 Ma (Masterman, 2004). The Rosario porphyry is thought to be the centre of hydrothermal alteration and hypogene mineralisation at Rosario. Third porphyry at Rosario is the dacitic Ines porphyry, although it is interpreted as a pre-mineralisation intrusion at Rosario yet it also contains the presence of hypogene mineralisation (Masterman, 2004).

The emplacement of the porphyries appears to have been influenced by the Rosario fault system thus implied a NW-trending to both porphyries. Furthermore, the Rosario fault system also acted as a control to the overprinting high sulphidation Cu-Ag massive veins, which crosscut the porphyry mineralisation at Rosario.

Figure 7-6: Typical lithology cross section of Rosario at 20NE, looking to NW (CMDIC internal presentation)

The host rocks in Ujina are broadly correlative to the ones at Rosario. The deposit is hosted within the Collahuasi formation, which is composed of a thick basalt andesite overlain by rhyolite and sedimentary breccias

S WS W N ES W N ES W N ES W

Gravels Collahuasi PorphyryAndesite DaciteRosario Porphyry Sediments


29 March 2012 Report No. 1292154001 33

(Bisso et al., 1998). The Collahuasi formation is intruded by several intrusions, including Ujina porphyry; igneous breccias, Doña Inés porphyry and Inca porphyry (see Figure 7-7). The major porphyries related to mineralisation are the Ujina porphyry and the Inca porphyry. The Ujina porphyry is the major host for the mineralisation at Ujina and is composed of a granodiorite stock with a 40Ar/39Ar age of 35.2 Ma ± 0.3 Ma (Masterman, 2004). In turn, the Ujina porphyry is intruded by the N and NW trending, granodioritic Inca Porphyry (Bisso et al, 1998).

Figure 7-7: Typical lithology cross section of Ujina at 128NE, looking to NE

At Capella Sur, the gravels thicken to 30 to 40 metres depth and are intercalated with clay horizons rich in copper and manganese. Copper wad predominates in this mineralised body and only minor crysocolla is found. Mineralisation at Capella Sur is lower grade and extends deeper into the basement rocks.

At Capella Este the copper mineralised zones deepen into basement rock forming a more voluminous mineralized zone with dimensions of 550 by 550 metres at depths between 45 and 120 metres below surface. The host rocks include acid volcanics as well as volcaniclastic and calcareous sedimentary sequences. Mineralisation occurs as chrysocolla, copper wad with some minor chalcocite and cuprite. It is unclear whether the Capella Este deposit is of exotic origin or whether it represents in-situ oxidation of weakly enriched sulphides.

7.2.3 Alteration Hydrothermal alteration at Rosario and Ujina is characterized by the typical alteration zonation of porphyry deposits in northern Chile (see Figure 7-8 and Figure 7-9). It consists of a central potassic alteration, largely

4,000m asl

4,400m asl

0 100m

Igneous Breccia

Paleogravels

Ignimbrite (9 Ma)

Inca Porphyry

Doña Porphyry

Ujina Prophyry

Mafic Dyke

Rhyolite

Andesite

Sediment

Permo-TriassicOligoceneMiocene

Miocene-Oligocene

2004 Pit

4,000m asl

4,400m asl

4,000m asl

4,400m asl

0 100m0 100m

Igneous Breccia

Paleogravels

Ignimbrite (9 Ma)

Inca Porphyry

Doña Porphyry

Ujina Prophyry

Mafic Dyke

Rhyolite

Andesite

Sediment


Miocene-Oligocene

Igneous Breccia

Paleogravels

Ignimbrite (9 Ma)

Inca Porphyry

Doña Porphyry

Ujina Prophyry

Mafic Dyke

Rhyolite

Andesite

Sediment


Miocene-Oligocene

2004 Pit


29 March 2012 Report No. 1292154001 34

related to the porphyry intrusions, and propylitic alteration at the periphery of the deposit. The area is overprinted by strong pervasive quartz-sericite (phyllic) alteration. Late argillic alteration is found locally with an abundance of kaolinite focused within fracture zones related to supergene alteration.

Hydrothermal alteration at Rosario involved multiple overprinting of alteration from various stages. According to Lee (1994) and Masterman (2004) there are four stages of alteration in Rosario. The earliest stage involved barren magnetite dissemination and veinlets. This is followed by quartz-biotite-albite and quartz-K-feldspar veins that are associated with biotite-albite-K-feldspar alteration within and around the Rosario porphyry. The transitional stage is characterised by the presence of quartz-molybdenite veins and the intermediate stage is characterised by quartz-pyrite-chalcopyrite veins with an illite-chlorite halo enveloping the veins. The last stage of alteration at Rosario involves the formation of high-sulphidation alteration localised at the Rosario faults. The alteration halo includes quartz-alunite-pyrite close to the high-sulphidation veins overprinted by pyrophyllite-dickite and passes through muscovite-quartz-pyrite to illite-smectite envelops.

Hydrothermal alteration at Ujina shows two main hypogene stages. The early stage is centred at the Ujina porphyry and characterised by a K-feldspar core grading into biotite alteration. The second stage alteration is vaguely recognised by the alteration halo of white mica-quartz-chlorite. The occurrence of kaolinite and smectite across the top of Ujina indicates weak supergene alteration close to the surface (Masterman, et al, 2004).

S WS W N ES W N ES W N ES W

Sericite (S )

B ioti tic (B )P o tasic (K)Skarn (S KA )

A rg ill ic

Ch lo r ite -se ric i te (C S )

Q uartz -se ric ite (Q S)


29 March 2012 Report No. 1292154001 35

Figure 7-8: Typical alteration cross section of Rosario at 20NE, looking to NW (CMDIC internal presentation)

Figure 7-9: Typical alteration cross section of Ujina at 128NE, looking to NE

8.0 DEPOSIT TYPES The mineral resources and mineral reserves in CMDIC are related to three major deposits: Rosario, Ujina and Rosario Oeste, and isolated oxides mineralized bodies: Capella, Rosario Sur Complex (Rosario Sur I (ex Dulcinea), Rosario Sur II (ex La Borracha) and Rosario Sur III (ex La Borracha Oeste)).

Ujina and Rosario are two world class Cu - Mo porphyry deposits. Ujina has a classic supergene profile with an upper leached zone that covers oxide and mixed copper mineralized bodies and mainly a very well defined blanket of high grade secondary copper sulphide that contains chalcocite and covellite. A large zone of primary sulphides, with chalcopyrite, is present below this horizon. Currently most of secondary sulphides have been mined and the mineral resources and mineral reserves stated in this report are mainly related to primary mineralization.

Copper mineralization at Rosario is associated with a series of northwest-trending faulting that controls Cu–Mo porphyry set-up with subsequent hydrothermal events. Over 95 percent of the deposit is related to hypogene mineralization.

Rosario Oeste is located toward southwest of Rosario and it has been classified as a large complex of high sulphidation pyrite-bornite-chalcopyrite-chalcocite- Ag-Au veins in his hypogene phases and mainly have been


29 March 2012 Report No. 1292154001 36

leached, oxidized and enriched forming bodies of high grade secondary copper sulphides mineralization and smaller proportions of copper oxides. These veins are closely linked to a series of NNW, NS, and NE structures, with sub vertical dip. The ore corresponds largely to secondary copper sulphides; chalcocite and bornite associated with pyrite, which are found in veins, veinlets, and to a lesser extent spread in structures. Small quantities of tenantite-tetrahedrite and enargite are founded within the suite of primary sulphides.

Oxide copper minerals are also found in small copper deposits named Capella and Rosario Sur complex (I, II & III). The deposits of Capella (Sur & Este) constitute near-surface exotic oxide copper deposits located between the Rosario and Huinquintipa mines, while Rosario Sur complex is locate to the south of Rosario Oeste and correspond to copper oxides related to local fault – veins The copper oxides are mainly chrysocolla and minor black oxides.

9.0 EXPLORATION Since the start of the operations at CMDIC has carried out infill drilling campaigns to update resource classification as well as exploration drilling inside the property. Near pit exploration has been successful in expanding the mineral resources base over the years.

Other exploration campaigns have been implemented in CMDIC using geophysical methods. The summary of geophysical surveys over the CMDIC deposits is described below:

During the period from 1991 to 1993, various geophysical surveys were carried out over the CMDIC Property including the following: Various IP/resistivity campaigns were completed during this 3 year period by Quantec Geofísica Limitada. In total, 31 lines were completed. All of these campaigns employed the same 300 m dipole-dipole array, with readings to N6, and survey lines were generally spaced very widely at either an 800 m or 1,000 m separation. The objective of the IP/resistivity surveys was to define the limits of the Rosario and Ujina mineralized porphyry systems, as well as search for possible additional mineralized systems.

A helicopter magnetic survey completed in 1991 which covered an area measuring 14 km east-west by 14 km north-south centered over the Rosario and Ujina deposits, with a line spacing of approximately 300m.

In 1993 some limited TEM and gravity surveys were completed during the period to the east and north-east of the Ujina Deposit.

During the period between August 2004 and September 2005, a 200 m moving in-loop Transient Electromagnetic (TEM) survey was completed by Quantec Geofísica Limitada over the greater Rosario mineralized system, south of the operating pit. Readings were taken every 50m, on lines spaced at 200 m, which provided a very high density of data.

During the period of November 2008 to February 2009, 9 additional IP/resistivity survey lines were completed by Quantec Geofísica Limitada in an effort to extend the historic coverage of the 1991-93 IP/resistivity surveys to the CMDIC property boundaries.

During the period of 2010 to 2011, NS and EW lines over part of Ujina , Rosario and Rosario Oeste were completed using a special electric survey MIMDAS, by GRS Chile. This system was effective in defining in depth the continuity of mineralized systems.


29 March 2012 Report No. 1292154001 37

10.0 DRILLING The CMDIC data set contains data from two types Diamond Drill Hole (DDH) and Reverse Circulation (RC).

RC and DDH are drilled for infill and exploration purposes following relevant geological information and the specific objectives for each campaign. The drilling tasks are performed by external contractors, following the CMDIC internal procedures.

Table 10-1 lists the number of drill holes and total meters drilled that have been included in the resource statement of the CMDIC.

Table 10-1: Drilling summary for data supporting the CMDIC resource models

Drill hole type

Rosario Rosario Oeste Ujina Capella Este Rosario Sur I - II - III

Total drill

holes

Total Meters

Total drill

holes

Total Meters

Total drill

holes

Total Meters

Total drill

holes

Total Meters

Total drill

holes

Total Meters

Surface DDH 819 324,430 424 275,119 664 166,943 137 15,177 Underground drill holes 34 4,232 RC 459 80,004 34 6,661 51 5,100 297 47,722 Total 1,312 408,666 458 281,780 664 166,943 188 20,277 297 47,722

Figure 10-1 and Figure 10-2 detail the drilling evolution along time for Rosario Oeste and Rosario.

Figure 10-1: Drilling evolution in time for Rosario Oeste

0

50,000

100,000

150,000

200,000

250,000

300,000

1993 2005 2006 2007 2008 2010 2011

Meters

Rosario Oeste drilling campaign by model

2011

2010

2008

2007

2006

2005

1993


29 March 2012 Report No. 1292154001 38

Figure 10-2: Drilling evolution in time for Rosario

The data from drill campaigns and used for the geological modelling and grade estimation comes from DDH and RC drill holes.

Rosario: 80% DDH and 20% RC;

Ujina: 100% DDH;

Rosario Oeste: 98% DDH and 2% RC;

Rosario Sur: 100% RC.

The distribution of drilling diameters performed at CMDIC is:

HWT. between 28 y 34%

HQ: between 26 y 31%

NQ: 40%.

10.1 Down hole survey Before 2005 down hole survey at CMDIC was measured with the Single Shot or Multi Shot systems. Since 2005, survey is measured with Gyroscope. The down hole survey measurements are taken at 10 m intervals to the end of hole. The measurements are taken by CMDIC technicians and directly entered into the drilling database.

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

2003 2006 2007 2007 2008 2009 2010 2011

Meters

Rosario drilling campaign by model

2011

2010

2009

2008

2007

2007

2006

2003


29 March 2012 Report No. 1292154001 39

10.2 Topographic Survey All topography surveying are conducted by CMDIC personnel and based on a local grid system. Previous to 2007 all topographic survey was carried out using total station system. Since 2007 a high definition GPS has been used. The QA procedure implies a second and independent measure for 5% of the collars.

11.0 SAMPLE PREPARATION, ANALYSES AND SECURITY 11.1 Logging The logging of data from drill core includes geological, geotechnical and physical attributes. This data is recorded using predefined standards and protocols.

The logging is conducted by external contractor supervised by CMDIC personnel. Until 2006 logging was carried out on paper sheets. From 2006 to 2008 all logging was done digitally using GVMapper software. In 2009 the acQuire system was implemented and still in use to date.

Geological logging considers lithology, hydrothermal alteration, mineralization, sulphides, weathering, vein types, textures and structures according CMDIC’s logging procedure that guides the geologists in the identification and description of the different geological attributes. Since 2009 X-Ray fluorescence equipment is used to support logging. This equipment provides an approximate grade for key elements.

As part of the geotechnical logging total core recovery, rock quality designation (RQD), Point Load Test (PLT) and fracture counts are routinely recorded.

11.2 Drill hole sampling Drill programs have been completed primarily by external contractors under supervision of CMDIC personnel. Reverse circulation (RC) sampling considers two conditions:

For dry samples splitting is performed each 2 metres. The full sample bucket is put through a riffle splitter to reduce the mass to half of the original sample. This is then split again to produce a 25% aliquot until a 10 to 15 kg sample is obtained.

For wet samples, a cyclone with a rotary splitter is used to obtain samples with 10 to 15 kg.

In both cases samples are weighted and the recovery is determined. The sampler collects the sample into a plastic bag and puts a tag with a unique identifier.

Diamond drill core is sampled at 2 m intervals with samples broken at lithology, mineralisation and/or alteration contacts. The sampling intervals are determined, marked, and tagged by the geologists. The core is then split in half using a hydraulic splitter. The position where the core is to be split is marked based on an internal CMDIC protocol. One half of the core is sent for mechanical preparation and chemical analysis and the other half remains stored on site for back up purpose. Since 2007 mechanical preparation is performed on site by external contractors (Geoanalítica S.A). The mechanical preparation procedure is summarized in Table 11-1. The mechanical preparation procedure considers the following:

Sample is weighed. Wet samples are dried in an oven at 105°C for 8 hours.


29 March 2012 Report No. 1292154001 40

The entire sample is crushed in a Boyd crusher. One granulometric test is performed for each 15 samples, 95% of the sample passes through a No. 10 Tyler mesh (1.70 mm).

After crushing, the sample is passed through a rotary splitter, where 1/16 of the sample is collected for chemical analysis, 0.75 to 1 kg of sample.

Pulverisation in an LM2 ring mill until 95% of the sample passes through a No 150 Tyler mash (0.105 mm). One granulometric test is carried out for each 20 samples.

Three samples of 150 g are collected by manually scooping with a spatula directly from the ring mill.

Table 11-1: Mechanical preparation procedure. STAGES DESCRIPTION

RECEPTION

• Creation of batch. • Sample label with bar code.

• Weight measure, one each 30 m.

DRYING

• Drying on electric oven 105° C during 4-8 hrs. • Each 30 m, register dry weight and determine humidity.

• Clean tray.

CRUSHER

• Sieve of the sample to <10 #Ty. • Crusher of the fraction > 10 # Ty. • Granulometric control 95 % a < 10 # Ty, one each 30 m. •Weight of granulometric sample. • Coarse blank, one each 30 samples

• Clean machines between samples.

SPLIT

• Splitting of the sample until obtain 0,8 Kg. aprox. • Generate coarse duplicate, one each 30 m. • Granulometric control < 10 # Ty, one each 30 m.

• Clean machines between samples.

DRYING • Drying on electric oven 105°C for 1 hour aprox.

• Clean tray.

PULVERIZATION

• Pulverization to < 150 # Ty. • Granulometric control 95 % < 150 # Ty. • Generate pulp duplicate one each 30 m.

• Clean between samples.

PACKING

• Three samples of +- 150 each one • Prepare the packing in cases.

• Check sample identification.


29 March 2012 Report No. 1292154001 41

11.3 Database Management CMDIC uses a Geoscientific Information Management System (acQuire) to centralize the drill hole information. This database contains all the geological information acquired since February 2007. The data acquired prior to that date are recorded on a Microsoft Access database.

Importing data to the official database is done through standard data entry procedures. The entries of information into the database, as well as modifying authorization, are regulated by strict permissions set by a nominated database administrator. The laboratories responsible for the chemical analysis deliver the assay information as csv files and the data is directly imported into acQuire. Prior to the data being available, the results are checked and signed off by the Chief Chemist.

All assay data obtained after 2005 is fully supported by assay certificates. However for previous campaigns, especially between 1981 and 1983, some of the data do not have the supporting assay certificates.

11.4 QAQC For all drilling programs developed by CMDIC, the process of sample preparation, assaying, analytical, and quality control procedures have always been done following the established internal protocols based on industry standard practices. The QAQC procedures were last updated in 2007. The on-site QA program includes the insertion of standard reference material (standards are generated using material from the mine) to monitor accuracy, coarse blank material (blanks) to monitor contamination and sample mix-ups, field, coarse and pulp duplicate to monitor precision.

For a regular 35 samples batch, 1 blank, 2 standards, 1 field duplicate, 1 coarse duplicate and 1 replicate, are used, totalling 6 QAQC samples. Assay values of CuT, Mo, and As are checked in the process. The QC procedure to define if the batch will be approved or rejected uses the standard deviations analysis and frequency of occurrence. The batches that are rejected are sent to re-analysis and are not included in the estimate. AcQuire software is used to monitor the results of QAQC samples.

11.4.1 Rosario Oeste QAQC Pre 2010 The QAQC analysis for samples pre 2010 considers the analysis of 318 drill holes with 207.344 m. QAQC data from drill holes drilled until 2007 indicated no obvious bias in the standard results, and only isolated values out of the acceptable range were observed. In these cases the whole batch was sent to re-analysis. Blank results indicate the absence of contamination. DDH and RC field duplicate indicated an absolute error above acceptable values, mainly associated to problems during core cutting that induced low representativeness and problems during the splitting of RC samples.

Rosario Oeste 2010 Blank results show no evidence of contamination for CuT and CuS. Standards show a good accuracy with virtually all of the samples within the acceptable limits. DDH duplicates show higher differences than expected, although there is no global bias. RC duplicates and coarse and pulp duplicates show good results.


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11.4.2 Rosario QAQC QAQC Previous to 2001 All the QAQC data previous to 2001 was reviewed by MRDI (MRDI, 2001), concluding that the results for CuT were acceptable and data can be used for estimate purpose.

QAQC Rosario 2001 Infill All analysis was done in CIMM Santiago laboratory, and results reported on the 2002 resource model report, (CMDIC, 2002). Results indicated acceptable result for CuT.

QAQC Rosario 2002-2003 Infill CuT indicated acceptable ratios of failure (<10%) and no evidence of bias were detected. Results were reported in the report associated to the resource model.

QAQC Rosario 2004-2006 Reports and registers of campaigns between 2004 and 2006 Rosary, have not been found.

QAQC Rosario Infill 2007 All analysis was performed at Geoanalítica in Antofagasta. Results indicate no obvious bias in the standard results. Blank results indicate absence of contamination. RC field duplicate indicated an absolute error near 30%, mainly associated to problems during the splitting of the samples in the rig and some loss of fine material in the cyclone. Coarse and pulp duplicates show adequate results.

QAQC Rosario Infill 2008 All analysis was performed at Geoanalítica in Antofagasta. Results of the standard samples indicate no obvious bias and blank results indicate the absence of contamination. RC field duplicates show an absolute error above acceptable limits, further investigation of this issue has indicated that it is associated to problems during sample splitting at the rig and losses of fine material in the cyclone. Coarse and pulp duplicates show acceptable results with no evidence of bias.

QAQC Rosario Infill 2009 All analysis was performed at Geoanalítica in Antofagasta and Coquimbo. Results indicate no obvious bias in the standard results. Blank results indicate absence of contamination. RC field duplicate continue to show absolute errors above acceptable values. Coarse and pulp duplicates show acceptable results with no evidence of bias.

QAQC Rosario 2010 All analysis was performed at Geoanalítica in Antofagasta and Coquimbo. Results indicate no obvious bias in the standard results. Blank results indicate absence of contamination, see Figure 11-1. DDH and RC field duplicate shows good correlation, see Figure 11-2. Coarse and pulp duplicates show acceptable results with no evidence of bias.


29 March 2012 Report No. 1292154001 43

Figure 11-1: CuT results for STD-09-02.

Figure 11-2: RC CuT results for RC field duplicates.

Expected Value 2SD 3SDError Normal

0.49

0.51

0.53

0.55

0.57

0.59

0.61

0.63

0.65

0.67

4-Jun-2

010

15-Jun

-2010

18-Jun

-2010

24-Jun

-2010

24-Jun

-2010

29-Jun

-2010

29-Jun

-2010

6-Jul-2

010

6-Jul-2

010

12-Jul-

2010

15-Jul-

2010

15-Jul-

2010

29-Jul-

2010

29-Jul-

2010

19-Aug

-2010

6-Sep-201

0

7-Sep-201

0

7-Sep-201

0

9-Sep-201

0

9-Sep-201

0

10-Sep-

2010

10-Sep-

2010

CuT_

AAS0

025_

pct

STD-09-02STD-09-02Standards by SequenceStandards by Sequence

RETURNDATE

Error Normal Error

0369

12151821242730333639424548

0 10 20 30 40 50 60 70 80 90 100

HA

RD

CuT_AAS0025_pctCuT_AAS0025_pct

Percent Population

Normal X=Y

0

1

2

3

4

5

67

8

9

10

11

12

13

14

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Che

ck

CuT_AAS0025_pctCuT_AAS0025_pct

Original


29 March 2012 Report No. 1292154001 44

11.4.2.1 Capella Previous to 2010 Only RC field duplicates were considered for drilling campaigns previous to 2010, one each twenty samples were sent for quality control. QA criteria considers a 20% difference as acceptance. About 90% of the duplicates meet the defined criteria, see Figure 11-3.

Figure 11-3: CuT results for RC field duplicates

Post 2010 QAQC carried out during the drilling campaigns consisted in the submission of blind duplicate samples. Both coarse (taken at the rig) and pulp duplicates were submitted Standards and blanks were not submitted as check samples. The results of these checks indicate poor reproducibility of the results. It is suspected that this is partly due to mix-ups in the sample numbering. Additional checks for total copper, obtained by comparing the composite assay to the original assays show better reproducibility although a laboratory calibration problem is noted for copper values below 0.5 %CuT. This bias should be investigated and discussed with the laboratory. The results of the duplicates shown the figures above show fairly poor comparisons between original and duplicate assays. The relative difference plot for total copper shows that 20% of the duplicates have relative differences greater than 20% for values above 0.1 %CuT. Much of the dispersion could be explained by mix-ups suggesting poor handling of the samples in the field.

0

20

40

60

80

100

0.001 0.01 0.1 1 10

Mea

n pe

rcen

tage

diff

eren

ce C

u%

Avg Cu%

Scatter plot for RC Field Duplicates

Approval threshold

CuT

off


29 March 2012 Report No. 1292154001 45

Figure 11-4: CuT results for pulp duplicates.

12.0 DATA VERIFICATION Data verification has been an integral part of all CMDIC drilling campaigns and resource estimation.

As part of the protocols the half core, coarse rejects and pulp samples are appropriately stored in racks located in a warehouse especially dedicated to this purpose.

As part of the Resource Audits performed by Golder and to ensure the information registered on the logging sheets is correctly transferred into the database, 5% of the drill holes in the database were selected and analysed to check for consistency. The comparison of the logging sheets against the database showed generally good consistency, especially in more recent drilling campaigns. Also during the audits, core from several drill holes were examined and compared to drill logs and assay certificates. No material discrepancies were noted during these checks.

Control Calidad - Muestreo y Análisis de duplicados

Cuerpo Capela-HuinquintipaVariable CuT

GRUESOOriginal Duplicado

Mínimo 0.00 0.00Máximo 7.23 7.65Promedio 0.30 0.30Desv.Est. 0.59 0.63N° Datos 929Correlación 0.86

Limite deteccion0.01

Valor minimo para differencia relativa0.03

CMDIC

Gráfico Diferencía Relativa

0%

10%

20%

30%

40%

50%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

% Acumulado

% D

ifere

ncia

Rel

ativ

a

Estándar para Grueso

Gráfico disperción

0

1

2

3

4

5

6

0 1 2 3 4 5 6Original

Dup

licad

o

QQ plot

0

1

2

3

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7

0 1 2 3 4 5 6 7Original

Dup

licad

o


29 March 2012 Report No. 1292154001 46

13.0 MINERAL PROCESSING AND METALLURGICAL TESTING 13.1 Mineral processing The mineral types at CMDIC can be divided into oxide/mixed and sulphide. The sulphide ore (approximately 90% of the total production) is treated in a conventional flotation mill which can handle nominal 160 ktpd with the concentrate being pumped 190 km to Port Patache, which is located 66 km south of Iquique. The port can take up to 60,000 dwt vessels.

The oxide/mixed material (approximately 10% of the total production) is treated using heap leach methods. The installed ore crushing capacity for this process is approximately 19 Ktpd. A SX-EW plant has been averaging 59 Ktpa of copper cathodes. Figure 13-1 graphically represents the simplified flow sheet for mineral treatment.

Figure 13-1: Simplified flow sheet for mineral treatment at CMDIC

Rosario Mine

Ujina Mine

Oxide Mines

Surge Pile

Stock Pile

Sulphides primary crusher

Oxides primary crusher

Secondary & tertiary crushers

Stock Pile

Flotation

Grinding and classification

Molybdenum plant

Filter plantCopper concentrate storage and dispatch

Puerto Patache

Concentrate transportation via 190 km pipeline

Silo

Agglomeration

Transport and pile formation

Leaching

Solvent extraction

Electrowinning Copper cathodes dispatch

Mineral extraction Sulphide line

Oxide line


29 March 2012 Report No. 1292154001 47

13.2 Metallurgical testing CMDIC routinely acquires geometallurgical data and updates predictive models. The data includes a suite of metallurgical test results that cover both grinding and flotation characterization.

In Rosario and Ujina the following metallurgical tests have been performed for grinding purposes:

JK Drop-Weight Test

Standard Ball Mill Wi Grinding Test

SPI Test

SMC Test

Torque Mill Grinding Test

Abrasion Test

In Rosario and Ujina the following metallurgical tests have been performed for Flotation purposes:

Rougher Flotation Exploratory Kinetics Test

Rougher Flotation Kinetics Test

First-Cleaner Flotation Kinetics Test

Second-Cleaner Flotation Kinetics Test

Locked Cycle Flotation Test

In Rosario the following metallurgical tests have been performed for Bio-Leaching purposes:

Leaching dump (run of mine) test and acid consumption (finished)

In Capella Este the following metallurgical tests have been performed for Leaching purposes:

Leaching column test and acid consumption (not performed in the current pilot plant)

In Rosario I and Rosario II the following metallurgical tests have been performed for Leaching purposes:

Leaching bottle and column test & acid consumption. (finished)

In Rosario Oeste the following metallurgical variability tests have been performed for grinding purposes:

Standard Ball Mill Wi Grinding Test

SPI Test

SMC Test

In Rosario Oeste the following metallurgical variability tests have been performed for Flotation purposes:

Rougher Flotation Exploratory Kinetics Test


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Rougher Flotation Kinetics Test

In Rosario Oeste the following metallurgical tests have been performed for Bio-Leaching purposes:

Leaching bottle and column test, acid consumption, and hydrodynamic characterization. (in progress)

In Ujina the following metallurgical tests have been performed for Bio-Leaching purposes:

Leaching column test and acid consumption. (finished)

14.0 MINERAL RESOURCE ESTIMATES 14.1 History For the Feasibility Study in 1995, resource models were generated for Ujina, Rosario and Huinquintipa. These were reviewed and audited by MRDI. In 1998, the Ujina resource model was updated by CMDIC staff with the support of Maptek. In November 2001, the Ujina 1998 model was updated using new mineral resource classification criteria similar to those used for the Rosario 2001 Model, as stated in the ‘Collahuasi Resource and Reserves, Memorandum November 15th, 2001’. Since 2006 and 2007, 16,877 metres of revere circulation drillings have been performed to improve the geometallurgical characterization of the sulphide material.

The Rosario resource model was updated in 2000 by CMDIC staff with the technical support of Geosystems Consultants. Following a review by the shareholders, in 2001 this model was updated using a revised resource classification scheme. The 2001 Rosario model was audited and approved by MRDI. Since the feasibility study of the Ujina-Rosario Transition Project 44,000 metres of drilling have been carried out in order to improve the model in the first years of mining. This included nearly 30,000 metres aimed at upgrading the resource classification in the first 3 years of the mine plan and 15,000 metres aimed at improving the estimates of high arsenic mineralization in the initial mining phases. A new resource model was completed at the end of November 2003. In 2004 the molybdenum resources were audited by AMEC. This model was updated in April 2006 with the infill drilling campaigns performed during 2004 and 2005.

In 2007 the Rosario resource model was updated by CMDIC staff. This version includes additional 15,000 meters of reverse circulation drill holes from the 2007 infill drilling campaign and 11,453 meters of diamond drill holes from a “near mine” exploration program named “Rosario Extension” that added new resources towards the southwest part of the deposit.

Between 2001 and 2002 drilling campaigns carried out west of Rosario led to the discovery of the exotic oxide copper deposits of Capella Norte, Este and Sur, and Huinquintipa Este. Resource models for these deposits were first constructed in 2003 and updated in 2004 with samples orientated at improving knowledge about the metallurgical response of these oxides. Mining of the exotic deposits started in 2005. These areas are to be covered at a later stage by waste rock dumps from the Rosario pit.

During 2007 a “near mine” exploration program of 1,788 meters around the exotic deposits was performed. This work allowed the identification of a small body of exotic copper mineralization named “Capella Oeste”. This material was included into 2007 - 2008 production plans.


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Rosario Oeste was discovered on 1991 when a geophysical IP anomaly was drilled. A total of 20 DDH drill holes with 10,581 meters were drilled confirming the existence of an important body associated to a sub vertical veins system with high Cu values and important zones of secondary enrichment. During 2004 the exploration was reinitiated with geophysics studies and 25 new DDH drill holes (Phase I). In 2005 the first geological model was finalised. During 2005 and 2006 a total of 28 DDH drill holes or 16,757 metres were drilled (Phase II). During 2006 drilling continued towards east and south of the recognized mineralised body, with 37 drill holes and 18,938 meters.

The first formal resource evaluation of Rosario Oeste deposit was developed at the end of November 2007. This work included a geological model built with 3D wireframes of main geological units. Grade estimation of copper, arsenic and molybdenum were performed using Ordinary Kriging over a database of 76,772 meters of drilling.

The summarized history of the CMDIC resource models, including the most recent updates, is included in Table 14-1, Table 14-2, Table 14-3 and Table 14-4 for Rosario, Ujina, Rosario Sur and Rosario Oeste respectively.

Table 14-1: Rosario resource model history Model Date Drill hole (m) Author Audit

Feasibility 1995 73,000 Magri & NCL Consultores MRDI 1998

Transition Ujina-Rosario study 2001 103,000

Cobre: CMDIC con Geosystems International (GSI) Arsénico & Fierro: CMDIC & MRDI

Kvaerner, 2001 & MRDI, 2001

Infill 2001 update 2002 140,000 CMDIC & Anglo American Chile

Infill 2002-3 update 2003 155,923 CMDIC AMEC 2004

Update including Extension Rosario & Infill 2004-7 2007 192,905 CMDIC

Infill 2008 update 2008 199,720 CMDIC Golder Associates

Infill 2009 update 2009 240,299 CMDIC

Infill 2009 update, Extension Rosario 2009 2010 351,338 CMDIC Golder

Associates



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Table 14-2: Ujina resource model history Model Date Drill hole (m) Author Audit

1998 update 1998 CMDIC & Maptek

Update on the resource classification. 2001 162,123 CMDIC – Anglo American

Chile - Falconbridge

Infill 2006-7 update 2008 178,546 CMDIC Golder Associates

Table 14-3: Rosario Sur resource model history Model Date Drill hole (m) Author Audit

2009 resource model 2009 5,846 CMDIC

Update incorporating La Borracha Oeste 2010 30,624 CMDIC

Update 2011 47,296 CMDIC Golder Associates

Table 14-4: Rosario Oeste resource model history Model Date Drill hole (m) Author Audit

Resource Model 2008 5,846 CMDIC Golder Associates

Update with new drill information 2010 224,966 CMDIC Golder Associates


The following sections describe the data, methodology and procedures related to the construction of the geological models and block grade estimates carried out for the different deposits considered in this Technical Report.


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14.2 Geological interpretation Geological modelling for Rosario, Rosario Oeste, Rosario Sur and Ujina includes: structural domains, mineral zones, lithology and hydrothermal alteration.

In all cases the available information (drill logging, field maps, pit shells, aerial photos, etc.) was used to develop a conceptual model of the geology. Thus, with the help of auxiliary lines and structural trends, 3D solids (using software Leapfrogtd or Vulcan td) were built for each model.

Rosario and Rosario Oeste The Rosario and Rosario Oeste geological modelling were carried out using Leapfrog® software to complete the lithology, alteration, mineralisation and structural 3D geological models. Typical sections interpreted by CMDIC geologists were used to guide the modelling process. For Rosario three EW sections were used. One of the sections was extended into the Rosario Oeste area, which was then used for construction of the Rosario Oeste model (Figure 14-1).

Figure 14-1: Rosario and Rosario Oeste "type-sections" used by Leapfrog to generate 3D geological models


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Ujina Ujina model is based on the 1998 update. This model was constructed using Vulcan software. Geological modelling considered the construction of lithology, alteration and mineralisation models, see Figure 14-6.

Table 14-5: Units considered in the Ujina mineralisation model. CODE Mineralogy Assamblage Pyrite LEACH Hematite ± Jarosite OXIDE Chrysocolla ± (Cuprite,Malachite,Brochantite) OXIDE WITH CLAY Chrysocolla ± Clay MIXED Chrysocolla,Chalcocite,Native,Copper Cuprite STRONG SECONDARY ENRICHMENT Chalcocite ± Chalcopyrite < 75 % WEAK SECONDARY ENRICHMENT Chalcocite,Chalcopyrite,Covellite < 75 % PYRITIC SECONDARY ENRICHMENT Chalcocite ± Covellite > 75 % PRIMARY Chalcopyrite ± Bornite > 75 %

Rosario Sur For Rosario Sur only mineralisation model is used for estimation purpose, see Figure 14-2. The geological model was interpreted separately for each deposit and constructed using Leapfrog software using vertical sections as a guide:

Rosario Sur I, 24 vertical sections each 25 m;

Rosario Sur II, 13 vertical sections each 35 m;

Rosario Sur III, 12 vertical sections each 35m

The mineralisation model considered the interpretation of 4 units; leach oxides, waste and veins.

Also a lithology model exists for the area. This model is used for density assignation. The lithology model is integrated for the three areas.


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Figure 14-2: Cross section N 77821: 4 m showing the mineralization model for Rosario Sur.

Capella Sur For the relatively shallow deposits of Capella Sur the lithological modelling was carried out on 50 m spaced cross sections, differentiating two main lithological units: surface gravels and basement rocks. In Vulcan these were used to construct three dimensional wireframe models that were then used to generate a block model with a basic block size of 10(X) x 10 (Y) x 5(Z) metres. Grade envelopes were interpreted at 0.1%, 0.3% and 0.7% total copper grade intervals. The manganese distribution was also zoned using grade envelopes of 10,000 and 20,000 ppm.

Capella Este Given that at Capella Este much of the copper mineralization is hosted in the basement rocks a more detailed geological model was interpreted in this area. Sections were interpreted along drill lines spaced at 50 metre intervals and these were used to assign codes to the block model constructed with a basic block size of 10(X) x 10 (Y) x 5(Z) metres. Sections for lithology, alteration and mineralisation were interpreted. Grade envelopes for Capella Este were interpreted at 0.1% and 0.3% total copper cut-offs. The manganese distribution was also zoned using grade envelopes of 10,000 and 20,000 ppm.


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14.3 Model definition The geological models supporting the resource estimation of CMDIC include a total of 8 independent models. The definition and relevant dates for these 8 resource models are described in Table 14-6.

Table 14-6: CMDIC Resource model definitions

Model Rosario Sur I

Rosario Sur II

Rosario Sur III

Rosario Oeste Rosario Ujina Capella

Este Capella

Sur

Data cut-off date Mar. 2011 Mar. 2011 Mar. 2011 Oct. 2010 Oct. 2010 Jul. 2008 Nov. 2009 Dec. 2003

Resource date Aug. 2011 Aug. 2011 Aug. 2011 Mar. 2011 Mar. 2011 Sept. 2008 Dec. 2009 Jan. 2004

Orientation (az/dip/pl) (45/0/0) (45/0/0) (45/0/0) (45/0/0) (45/0/0) (90/0/0) (90/0/0) (90/0/0)

Origin East 30,292.92 30,292.92 29,769.67 30,080.76 30,930.00 35,909.21 26,000.00 27,300.00

Origin North 76,292.89 76,292.89 76,816.15 76,747.97 78,930.00 77,345.94 80,400.00 80,400.00

Origin Elevation 4,395.00 4,395.00 4,495.00 3,205.00 3,205.00 3,820.00 4,345.00 4,300.00

Parent block size 10x10x10m 10x10x10m 10x10x10m 20x20x15 20x20x15 20x20x15 10x10x10m 10x10x5m

No. Blocks parent 1,680,000 1,680,000 115,500 4,498,570 3,243,920 1,312,200 144,500 1,190,000

Sub block size 2x2x2m 2.5x2.5x2.5m 2.5x2.5x2.5m 5x5x2.5m 5x5x2.5m 5x5x5m - -

No. Blocks sub 210,000,000 107,520,000 7,392,000 743,279,040 311,416,320 62,985,600 - -

14.4 Contact analysis Contact analysis has been consistently carried out for all units and for all estimated variables in order to define the nature of grade transitions between estimation domains. The analysis has determined that all boundaries are hard, which implies that all variables have been estimated using samples exclusively from within the estimation domain. Examples of contact profile plots are included in Figure 14-3 and Figure 14-4 for relevant domains in Rosario and Ujina respectively.


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Figure 14-3: Contact profile: total copper - primary and pyritic primary domains for Rosario

Figure 14-4: Contact profile: total copper - secondary and primary domains for Rosario Oeste

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14.5 Risk adjustment No direct grade capping was performed for resource estimation purposes; the spatial influence of high grades was restricted in the kriging plans where necessary. This process consists of controlling the influence of high grades within predefined search volumes.

14.6 Variography Correlogram maps were initially calculated to help defining the main directions of continuity for each variable. This was done individually for each estimation domain. An example of variogram maps has been included in Figure 14-5 for Rosario.

Experimental correlograms were calculated in 3D and variogram models fitted in the three main directions of continuity. Down-the-hole correlograms were calculated to define the nugget effect. Figure 14-6 shows an example for total copper grades in Rosario, where the adopted model is overlaid to the experimental correlogram values.

Figure 14-5: Correlogram map for total copper - primary sulphides in Rosario


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Figure 14-6: Correlogram model for total copper - primary sulphides in Rosario


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14.7 Grade interpolation A mineral inventory (block model) for each deposit was estimated using established geostatistical techniques following comprehensive statistical and exploratory data analysis (EDA). The evaluation of appropriate geological groupings for combination into statistical estimation populations was undertaken through the iterative statistical definition of estimation domains for each element to be interpolated using spatial declustered statistics.

The estimated elements are total copper, soluble copper, molybdenum and arsenic, except for the Rosario Sur deposits. Block grade interpolation was carried out using three-pass ordinary block kriging on variable block sizes (Table 14-6) and each pass reflected the various ranges established by the correlogram models for each element and estimation domain using the Ordinary Kriging (OK) algorithm for most of the domains. Once the grade estimation has been performed, the model is reblocked so that its dimensions are further used in future mine planning and is currently envisaged as the selective-mining unit (SMU) for the projected operation.

14.7.1 Rosario The estimation domains defined for total and soluble copper in Rosario are defined by mineral zone for background (porphyry) units: leached, oxides, mixed, secondary, primary and pyritic zones. Additional domains are defined via indicator kriging for high copper content veins. The process determines the proportion of vein present in each block.

Molybdenum estimation domains are defined based on total copper domains and adding lithological controls, whereas arsenic grade estimation domains are defined via indicator kriging for three thresholds.

Ordinary kriging in three passes is used in the estimation of all variables for Rosario. Directional correlograms were calculated and modelled for all variables and estimation domains. Hard boundaries are defined for all estimation domains and variables.

14.7.2 Rosario Oeste The same estimation domains are defined for total copper, soluble copper and molybdenum in Rosario Oeste. These are defined based on a mineral zone differentiation along with alteration controls. Arsenic estimation units are defined using a similar mineral zone – alteration control, but the combinations are different from the ones used for the rest of the variables, resulting in a larger number of estimation domains.

Ordinary kriging in three passes is used in the estimation of all variables for Rosario Oeste. Directional correlograms were calculated and modelled for all variables and estimation domains. Sample sharing is not implemented in the estimation of grades in Rosario Oeste, this is supported by the results of the contact analysis.

14.7.3 Ujina Copper grades are estimated in domains which are defined by mineral zone controls: leached, mixed, oxides, secondary enrichment, primary enrichment and a primary pyritic halo zone. Based on these domains, molybdenum and arsenic define their mineralization controls, but oxides, mixed and secondary zones are grouped into a single estimation domain.

Ordinary kriging in three passes is used in the estimation of all variables for Ujina. Directional correlograms were calculated and modelled for all variables and estimation domains. According to the results of the contact analysis performed for all variables and domains, no soft boundaries were applied in the kriging plans.


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14.7.4 Rosario Sur The three deposits that comprise the Rosario Sur complex use different estimation domain definitions for total and soluble copper. The estimation units are the same for both variables and are defined as described below:

Rosario Sur I: based on mineral zones the estimation domains are separated into waste, leached, sulphides and two oxide units which are limited by the Dulcinea fault into north and south domains.

Rosario Sur II: oxide and leached zones are used for kriging purposes. The total and soluble copper grades are assigned for the remaining waste unit.

Rosario Sur III: estimation domains are separated into veins, oxides and background. As for Rosario, veins are defined via indicator kriging, where the process determines the proportion of vein present in each block.

All domains use correlogram models to describe the grade variability in the kriging plans.

Different estimation approaches were implemented for the Rosario Sur deposits:

Rosario Sur I used ordinary kriging to estimate copper grades. The oxides domain was estimated in 3 estimation runs, while the rest of the units were estimated in a single pass. Hard boundaries were used between all estimation domains.

Only the copper grades for the oxides estimation domain were estimated Rosario Sur II using geostatistical tools. In the remaining domains grades were assigned based on declustered statistics from sample data.

All domains in the Rosario Sur III were estimated via ordinary kriging in 4 passes. Azimuth and dip values that defined the orientation for the search ellipsoids were previously obtained for each block based on an interpolation via inverse distance squared from the geological interpretation data. All contacts were defined as hard, hence no samples were shared between units in the estimation process.

14.7.5 Capella Estimation units for Capella Sur are defined by grade shells at the following ranges:

0.1% - 0.3% CuT

0.3% - 0.7% CuT

> 0.7% CuT

Grade shells are also used in the definition of the Capella Este estimation domains, but mineral zones are also used as a controlling variable.

The thresholds used for Capella Este are the following:

0.1% - 0.3% CuT

> 0.3% CuT

The mineral zones that break these grade shells to define the final estimation units are: Copper Wad / Pitch, Chrysocolla and Mixed zones.


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Correlograms were calculated and modelled for all domains and grades were estimated via Ordinary Kriging in a single pass.

14.8 Bulk density model Density samples are systematically collected every 20 m and must be of at least 10 cm long, they are properly labelled, protected and stored. The density measurement methodology is the wax-coat water immersion method.

Densities are assigned to each block model according to the following methodologies:

Rosario Oeste: density is estimated using OK from a database of 2,713 density samples.

Rosario: density block values at Rosario are estimated using Ordinary Kriging from a database of 1,851 samples.

Ujina: density values at Ujina are strongly controlled by the mineralisation zones and thus assigned the block model with the averaged density values. This is based on 1,023 samples.

Rosario Sur, due to their geological similarities the same values of Rosario Oeste are used for Rosario Sur.

Capella: Density values are assigned by lithology based on density data from nearby deposits with similar geological features (Rosario) due to the scarce number of samples available for the deposit these.

14.9 Validation of block model estimates Validation of the block estimates was performed using visual validations, swath plots, scatter plots, QQ plots and probability plots between samples and blocks estimates. The grade estimates were also compared to composite grades in sections and plan views. Reconciliation exercises are routinely carried out in the operating mines.

Examples of swath plots for total copper in secondary domains are included in Figure 14-7 and Figure 14-8 for Rosario and Rosario Oeste respectively.


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Figure 14-7: EW swath plot for total copper - Rosario secondary domain

Figure 14-8: NS swath plot for total copper - Rosario Oeste secondary domain

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32000 31900 31800 31450 31350 31200 31100 31000 30850 30750 30650 30550 30400 30300 30200 30000

CuT

[%]

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ocks

/ N°

Sam

ples

EW swath coordinate

EW swath plot for total copper - Rosario secondary domain

n_block n_samp cut_block cut_samp

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[%]

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ocks

/ N

°S

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es

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NS swath plot for total copper: Rosario Oeste secondary domain

n_block n_samp cut_block cut_samp


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When production data is available, resource models are reconciled against blast hole data. Historical reconciliation exercise examples are included in Figure 14-9, Figure 14-10 and Figure 14-11 for tonnage, total copper grade and copper content in high grade sulphides respectively.

The reconciliation results over the years are remarkably good supporting the resource estimation methodology performed by CMDIC.

Figure 14-9: Historical reconciliation: tonnage 2004-2011

0

5,000,000

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2004 2005 2006 2007 2008 2009 2010 2011

Historical Ton Reconciliation Budget vs Short Term Model 2004‐2011

Ton Short Term Model Ton Budget Model


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Figure 14-10: Historical reconciliation: CuT grade 2004-2011

Figure 14-11: Historical reconciliation: fine copper 2004-2011

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THistorical Cu Grade Reconciliation Budget vs Short Term

Model 2004‐2011

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2004 2005 2006 2007 2008 2009 2010 2011

Historical CuTon Reconciliation Budget vs Short Term Model 2004‐2011

Cu Ton Short Term Model Cu Ton Budget Model


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14.10 Resource Classification The criteria used to assign blocks into Measured, Indicated and Inferred resource categories is based on drill hole spacing depending on groupings of mineral zones. In practice, these grids have been calibrated with search radii applied to Inverse Square Distance (ISD) runs (Table 14-7).

Each ISD run required a different data configuration depending on the mineral zone. The restrictions applied to each mineral zone are shown in Table 14-8 and Table 14-9 for Rosario and Ujina respectively. The classification was performed in two passes, the first defining Measured and the second defining Indicated resources.

The results were re-blocked and a smoothing procedure was applied to avoid the “salt-and-pepper” effect.

Table 14-7: Resource classification criteria: Rosario and Ujina

Classification Mineral zone Search radii Referential

drilling grid (m)r1 (m) r2 (m) r3 (m)

Measured Leach - oxide - mixed - secondary material 50 50 30 70 x 70 Primary material 70 70 45 100 x 100

Indicated Leach - oxide - mixed - secondary material 100 100 50 140 x 140 Primary material 150 150 60 212 x 212

Inferred Leach - oxide - mixed - secondary material 250 250 100 350 x 350 Primary material 250 250 100 350 x 350

Exceptions to the resource classification criteria are the following:

The oxide deposits of Capella were drilled to an approximate grid of 50 m x 50 m and have been classified as indicated resources.

Rosario Oeste resources are 100% classified as Inferred.

Table 14-8: Data configuration for resource classification runs: Rosario

Classification Mineral zone unit Configuration

Min samples Max samples Max samples/DH

Measured Leached - Oxides - Mixed - Sec. Sulph. 6 16 3 Primary Sulphides - Pyritic Primary S. 8 16 3

Indicated Leached - Oxides - Mixed - Sec. Sulph. 4 16 3 Primary Sulphides - Pyritic Primary S. 6 16 3

Inferred Leached - Oxides - Mixed - Sec. Sulph.

4 16 2 Primary Sulphides - Pyritic Primary S.


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Table 14-9: Data configuration for resource classification runs: Ujina

Classification Mineral zone unit Configuration

Min samples Max samples Max samples/DH

Measured Leached - Oxides - Mixed - Sec. Sulph.


Indicated Leached - Oxides - Mixed - Sec. Sulph.


Inferred Leached - Oxides - Mixed - Sec. Sulph.


In the case of the Rosario Sur deposits, a similar resource classification procedure was implemented but more restrictive search ellipsoids were targeted to define each classification. All search ellipsoids were oriented N45W. The search radii and sample configuration are described in Table 14-10 for Rosario Sur I and in Table 14-11 for Rosario Sur II and III. It is observed that the resource definition used for Rosario Sur II and III is more restrictive in search distances as well as in the sample configuration scheme, ensuring that samples from at least two drill holes are used.

Table 14-10: Resource classification criteria: Rosario Sur I

Classification Mineral zone Search radius

Min samples Max samplesR1 (m) R2 (m) R3 (m)

Measured Leach - oxide - sulphides 50 30 15 2 8 Indicated Leach - oxide - sulphides 100 40 20 2 8 Inferred Leach - oxide - sulphides 200 80 70 2 8

Table 14-11: Resource classification criteria: Rosario Sur II and III

Classification Mineral zone Search radius

Min samples

Max samples

Max samples per DH R1

(m) R2 (m)

R3 (m)

Measured Leach - oxide - sulphides 30 30 25 8 16 4

Indicated Leach - oxide - sulphides 50 50 30 12 24 4

Inferred Leach - oxide - sulphides 70 70 70 12 24 4


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14.11 Dilution Considerations The block grade dilution related to the geology boundaries is incorporated to the final block grades by considering the proportion of each geological population within each block. This approach accounts for grade dilution related to geological contacts and provides similar results to what is normally referred to as “partial block” grade interpolation. Reconciliation results indicate that the level of dilution produced by the estimation method and subsequent consideration of proportions to derive tonnes and grades are appropriate for this type of large scale mining operation.

14.12 Resource Definition In order to ensure that the stated mineral resources represent mineralization with reasonable prospects for eventual economic extraction:

Mineral Resources at Rosario and Rosario Oeste are stated above cut-offs of 0.30% CuT for sulphides, 0.5% CuT for mixed and 0.4% CuT for oxides.

Mineral Resources at Ujina are stated above cut-offs of 0.30% CuT for sulphides, 0.5% CuT for mixed and 0.3% CuT for oxides.

Mineral Resources at Capella are stated above cut-offs of 0.30% CuT.

Mineral Resources at Rosario Sur are stated above cut-offs of 0.25% CuT.


Geological dilution is included in the resource block models and mineralization outside these pit shells is not reported in the resource estimates.

Two examples for the resulting classification of resource models are included in Figure 14-12 and Figure 14-13 for Ujina and Rosario respectively.


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Figure 14-12: EW section (N 78,445 ± 50m) showing the Ujina resource classification

Figure 14-13: Plan view (elevation 4,150 ± 7.5m) showing the Rosario resource classification

Measured resourcesInferred resourcesIndicated resourcesNot classified

Measured resourcesInferred resourcesIndicated resourcesNot classified


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14.13 Mineral Resource Statement Dr. Marcelo Godoy, MAusIMM (CP) and Principal Geostatistician and Mining Engineer with Golder has reviewed, verified and takes responsibility of the December 31, 2011 Resource Estimation Update of the Collahuasi Mineral Resources. Dr. Godoy is a qualified person and independent for the purposes of National Instrument 43-101.

Mineral resources quoted are inclusive of reported mineral reserves. No modifying factors have been applied to the mineral resource data. Mineral resources are estimated and reported on 100% basis. All tonnages are reported on a dry basis. Table 14-12, Table 14-13, Table 14-14 and Table 14-15 summarize the mineral resource figures for Rosario, Rosario Oeste, Ujina and the exotic oxide deposits (Capella Sur & Este and Rosario Sur) respectively.

Table 14-12: CMDIC mineral resources for the Rosario deposit as at 31 December 2011

Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.4 %CuT) Indicated kt 3 0.67 Inferred kt 2,108 0.49


Sulphides (Cut-off: 0.3 %CuT) Measured Mt 267 0.99 Indicated Mt 2,251 0.86 Inferred Mt 1,462 0.85

Table 14-13: CMDIC mineral resources for the Rosario Oeste deposit as at 31 December 2011


Oxides (Cut-off: 0.4 %CuT) Inferred kt 1,351 0.60 Sulphides (Cut-off: 0.3 %CuT) Inferred Mt 1,683 0.77

Table 14-14: CMDIC mineral resources for the Ujina deposit as at 31 December 2011


Oxides (Cut-off: 0.3 %CuT) Indicated kt 153 0.92 Inferred kt 505 0.85


Sulphides (Cut-off: 0.3 %CuT) Measured Mt 112 0.76 Indicated Mt 879 0.64 Inferred Mt 776 0.62


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Table 14-15: CMDIC mineral resources for the exotic oxide deposits as at 31 December 2011 Deposit Classification Unit Tonnage Grade (%CuT)

Capella Sur & Este (Cut-off: 0.3%Tcu) Indicated Mt 6 0.68

Rosario Sur (Cut-off: 0.25%Tcu) Measured Mt 33 0.60 Indicated Mt 5 0.57 Inferred Mt 1 0.47

Important information regarding the mineral resources disclosed in the above tables:

The Measured and Indicated Mineral Resources are inclusive of those Mineral Resources modified to produce the Mineral Reserves.



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15.0 MINERAL RESERVE ESTIMATES CMDIC’s mining operations correspond to a series of open pit mines located in the Region I of Chile, about 225 km by road southeast of the city of Iquique. The office and camp sites are located at 3,800 m.a.s.l. The pits and mill are located at elevations up to 5,000 m.a.s.l.. Currently, the main operating mine is the Rosario pit. Additional ore is currently coming from the Capella oxide pits. The original pit where the operations started, Ujina, is now not currently in production but is part of the Life Of Mine (LOM) plan.

The ore at Collahuasi can be divided into oxide/mixed and sulphide. The sulphide ore is treated in a conventional flotation mill which can handle 130 ktpd with the concentrate being pumped 203 km to Port Patache which is located 66 km south of Iquique. The oxide/mixed material is treated using heap leach methods. The installed ore crushing capacity for this process is approximately 19 ktpd. A SXEW plant has been averaging 59 ktpa of copper cathodes.

A key aspect of Mineral Reserve estimation for an open pit mine is to have a suitable pit outline that meets all the economic, mining and other requirements for reporting Mineral Reserves. CMDIC’s engineers report Mineral Reserves within a fully developed mine designs backed by schedules and financial analysis.

Pit optimisations were carried out using Whittle Four X (Whittle) by Gemcom. Whittle uses an implementation of the Lerchs-Grossman (LG) Algorithm to develop optimum pit shells. These shells are based on a specific set of mining parameters (geological model, mining and processing costs, metal prices, metallurgical recoveries and pit slope recommendations). All Inferred mineral resources have been assigned to the waste category for the purpose of pit optimisation and scheduling.

The optimised pit shells serve as a starting point for the detailed pit design and the subsequent development of a LOM plan. Operational mine designs for the ultimate pits and mine phases were created using Vulcan software from Maptek. The definition of the economic extraction sequences was established based on Whittle’s nested pits.

An optimized cut-off grade strategy for the LOM was derived using COMET software. This software applies K. Lane’s definition to include time discount factors into the estimation of cut-off grades. The logic was used for simultaneous optimisation of cutback sequences and cut-off grade policies for the LOM. The optimisation was configured with a Net Present Value (NPV) objective function which means that the optimization modifies the operating policies to maximise NPV. Since NPV is derived from the discounted cash flows, the cash flow calculation must accurately reflect cost and revenue drivers. Constraints on the schedule also play a key role in ensuring that only valid operating policies are considered. The constraints used include equipment usage (e.g. restrictions on truck assignment and maximum movement per cutback), pit geometry, access (sinking rates) and process capacities (conveyor limits, SAG time, recovery and concentrate grades) among others.

The mining costs used in the optimisation and mine scheduling work are based the actual costs from previous year and in line with forecasted budget developed by CMDIC.

The block grade models are estimated by Ordinary Kriging of drilling samples composited to a 15 m bench height. Historical reconciliation results indicate that the level of smoothing incurred during block grade estimation provide a realistic estimation of geological dilution and mine recovery therefore no additional dilution is considered in converting mineral resources into mineral reserves.


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The QP has been carried out Mineral Reserves audits of CMDIC since 2007 and has reviewed the methodology used and the results obtained for the Reserve Estimation Update carried out by CMDIC in 2011. Mineral Reserves have an effective date of December 31, 2011. The QP considers that the conversion of the Mineral Resources into Mineral Reserves was based on appropriate mine design and planning. In particular, dilution and mine recovery are supported by historical data. The tonnes and grades are reported at an appropriate economic cut-off grade based on documented costs and prices.

The numbers have been checked and are considered to be appropriate for the purpose of public reporting in that the mineral reserves provide an acceptable prediction of the available material expected from mining. The mineral reserves disclosed for the CMDIC operation include only mineralization classified as Measured and Indicated Resources and are presented in Table 15-1, Table 15-2 and Table 15-3. The figures are provided at the appropriate level of precision and comply with all disclosure requirements for mineral reserves set out in the National Instrument 43-101.

Table 15-1: CMDIC Mineral Reserves for the Rosario deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.4 %CuT) Probable kt 3 0.67

Mixed (Cut-off: 0.5 %CuT) Proven kt 16 0.60

Probable kt 40 0.52

Sulphides (Cut-off: 0.3 %CuT) Proven Mt 211 1.13

Probable Mt 1,694 0.84

Table 15-2: CMDIC Mineral Reserves for the Ujina deposit as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Oxides (Cut-off: 0.3 %CuT) Probable kt 153 0.92 Mixed (Cut-off: 0.5 %CuT) Probable kt 157 1.78

Sulphides (Cut-off: 0.3 %CuT) Proven Mt 74 0.90 Probable Mt 746 0.64

Table 15-3: Mineral Reserves for the Oxide deposits as at 31 December 2011 Material type Classification Unit Tonnage Grade (%CuT)

Capella Sur & Este (Cut-off: 0.3%CuT) Probable Mt 6 0.68

Rosario Sur (Cut-off: 0.25%CuT) Proven Mt 21 0.59 Probable Mt 4 0.57

Sulphide Mineral Reserves at Rosario and Ujina are reported above an operational cut-off of 0.3% CuT.

Oxide Mineral Reserves at Capella Sur, Capella Este, Rosario Sur are reported above an operational cut-offs >0.25% CuT.


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Table 15-4: CMDIC mineral reserves in Stocks

Material type Classification Unit Tonnage Grade (% CuT)

Oxides (in-stock) (Cut-off: 0.3%CuT) Probable Mt 3 0.72 Mixed (in-stock) (Cut-off: 0.5 %CuT) Probable Mt 2 0.83 Sulphides (in-stock) (Cutoff: 0.4%CuT) Probable Mt 135 0.61

To the QP’s knowledge, there are no known environmental, permitting, legal, title, taxation, socioeconomic, marketing, political, or other relevant issues which may materially affect the estimate of mineral reserves stated above.


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16.0 MINING METHODS The mining method applied since the beginning of the operation, which will not change for the LOM, it is conventional truck and shovel open pit mining. Facilities at the mine site include the open pits (Ujina, Rosario and Capella), oxide plant, sulphide concentrator and a comprehensive infrastructure including a permanent camp, tailings storage facility and two 203 km long concentrate slurry pipelines.

The main final saleable products produced at CMDIC are copper concentrate (90%) and cathodes (10%). The planned sulphide concentrator feed is approximately 150 ktpd for 2012 and 2013, and 160 ktpd from 2014 onwards. The disclosed sulphide mineral reserves above 0.30% CuT are sufficient to sustain the operations for 49 years (since 2012). According to current oxide reserves and considering the planned production rate of 25 ktpd, leaching production is sustained until 2017.

The current total rock movement at CMDIC is 750 ktpd (ore and waste). The material is presently excavated by a fleet composed by 10 electric rope shovels (4x56 yd3 and 6x73yd3), two Komatsu PC5500 hydraulic shovels and three Le Tourneau FEL L-1850. It is hauled by a fleet of seventy three 240 t and 300+ class haul trucks. There are well maintained access roads from the pits to other mine areas such as stockpiles, ROM, waste dumps, tailings, camp and processing plants.

All material between breakeven and the variable operating cut-off grades is defined as low-grade material and will be stockpiled for future treatment. It may also be treated in an alternative process (sulphide leach) which is currently being studied.

16.1 Life of Mine Plan The mineral reserves for CMDIC are produced as part of their LOM mine planning process. Each year a detailed mining plan is elaborated from the best alternative evaluated as part of a strategic review. Table 16-1 gives the overall mine production figures for the LOM 2011. The low grade ore is the material between the mineral reserve cut-off of 0.30% CuT and the variable optimized cut-off used in a particular year.

16.2 Mine planning process The long term planning process used at CMDIC for the development of the LOM Plan is summarised as follows:

Open pit optimisation using Whittle Four-X Software.

Develop phases (cutbacks) within Whittle pit shells. Mostly this is about making changes to the last phase or adding a new one.

Design mine phases and obtain material within each phase to be used in the mine planning software. Collahuasi uses Vulcan to perform this task.

COMET is used to schedule and sequence the operations for the LOM and to determine the best cut-off policy on a yearly basis.

The first profile of material movement for the production schedule is checked to ensure an exposed ore equivalent to 3 months is maintained using an Ore Depletion Chart. This shows ore exposure, equipment requirements on a pushback basis over time.

Finally, the normal mine planning routines of dump design, haul profile and equipment scheduling is carried out. This data was then used for cost estimation.


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Dumps are designed to match the schedule.

Haul profiles are developed from the plans with truck cycle times and productivities then calculated. These results are used with availability and utilization factors to determine the truck requirements for a period.

These plans show the development of the mine over time. They should demonstrate the logic of the mining plan and the ability to achieve production using suitable ramps and reasonable advance rates.

The information provided by CMDIC demonstrates that the mine planning process is being carried out to a high standard. The long term planning processes are sound and are competently carried out by the engineers.

Table 16-1: Summary of LOM plan

Mine Production Unit 2012-2060

Sulphide Ore Mt 2,419

%CuT 0.86

Low Grade Sulphide Ore Mt 290

%CuT 0.42

Oxide + Mixed Ore Mt 35

%CuT 0.89

Sulphide Ore in Stocks Mt 2.9

%CuT 1.07

Low Grade Sulphide Ore in Stock Mt 113.8

%CuT 0.58

Oxide Ore in Stocks Mt 25.2

%CuT 0.72

Waste Mt 10,331

Total Mt 13,674

16.3 Whittle optimization The most important aspect of Mineral Reserve estimation is to have available a suitable pit outline. At Collahuasi this is achieved by carrying out a Whittle optimisation. The mine planning department receives the block models from the Geology department. A mining model is developed from the Mineral Resource model by adding some usable variables such as ore type considering the categories and slope zones to control the pit angles. The model is also cut to the appropriate topography. The model is then exported and a Whittle model created.


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16.3.1 Costs and Prices The mining costs used in the optimisation work are based real costs as at April 2011. Table 16-2 shows the average forecast cost used as the Whittle reference mining cost. The costs reconcile with the historical figures and are reasonable for use as Whittle input. Golder checked that the costs had been properly applied in the Whittle optimisation. In general the costs used are properly supported by historical costs and are also in line with other operations of the same size in Chile.

Table 16-2 Whittle mining costs

Mine $/t rock

Rosario Mine 1.89

Ujina Mine 2.07

Oxide Pits 1.44

Mining Adjustment Factors (MAF) were calculated into the block models using a script or macro prior to exporting the Whittle models. The reference mining cost is adjusted from the base price using factors that consider a varying hauling distance depending on the block’s position. This was performed for each pit.

The Whittle processing cost parameters used in the open pit optimisation are summarised in Table 16-3. These costs were found to be reasonable and supported by an economic model.

Table 16-3 Whittle processing costs

Cost Area $/t Ore

Processing Sulphide (incl. G&A) 10.07

Processing Oxide (incl. G&A) 5.87

The copper price and selling costs used for the Whittle optimization are presented in Table 16-4. This is used as part of the input data for the Whittle optimisation. The difference between the Reserve and Resource cases is $0.50/lb in copper price. These costs appear reasonable and are appropriately applied.

Table 16-4: Whittle copper and molybdenum price and selling cost Item Whittle

Copper Price ($/lb) (Reserves) 2.30

Molybdenum Price ($/lb) 14.0

Selling Costs Sulphide ($/lb) 0.37

Selling Costs Heap ($/lb) 0.41


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The metal prices used for pit optimization are less than the average copper and molybdenum prices obtained over the three years prior to December 31, 2011.

New oxide pits for Capella Sur, Capella Este, Rosario Sur I&II were defined for a short term copper price of US$2.80/lb. The short term copper price was used because the pits from Capella will be completely depleted during the first semester of 2012. Rosario Sur I&II will be depleted from 2012 to 2015.

16.3.2 Pit slopes During 2011, new geotechnical information was included in the LOM and was used to update the slope angles used in previous designs. For the purpose of pit optimization the geotechnical model was simplified to derive global slope angles. These are presented in Figure 16-1.

Figure 16-1: Slope Angles applied to Whittle optimizations of Rosario and Ujina.

16.3.3 Optimisation results For the LOM plan, the Whittle models were optimised for a series of revenue factors and the ultimate pits were selected based on the maximum NPV criterion. Table 16-5 presents a summary of the ultimate pits selected for Rosario and Ujina.


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Table 16-5: Summary of Final Pit Results for Rosario and Ujina Item Rosario Ujina

Cu Price (US$/lb) 2.30 2.30

Block Model Rosmb_mar11rbk.bmf Ujibkuji0311rbk.bmf

Recovery Model 2011 Model 2011 Model

Topography April 2010 October 2011

Pit Number 68 66

Pit Size (Mt) 11,668 2,530

Mill Feed (Mt) 2,173 901

Stripping Ratio 4.37 1.80

CuT (%) 0.9 0.69

Cu Recovery (%) 85.2 83.8

Mo (ppm) 277 167

Mo Recovery 57.20 53.09

16.4 Pit Design The nested pit shells from the optimisation were imported into Vulcan software. These were then used to guide the design work. A check on the design against the initial Whittle shell is done to ensure the outline is properly followed. The Whittle shells are used as a guide for developing the phases design. Two or more shells may have to be joined to allow a phase width minimum of 60 m. The base parameters for mine design are summarised in Table 16-6.

Table 16-6: Mine design parameters Item Value

Phase Width 180-200 m

Minimum mining width 60 m

Bench Height 15 m

Ramp Width 38 m

Catch berms 25-40 m

Ramp gradient 10%

Each phase was individually designed using Vulcan. The design was checked to ensure it integrates with other phases, that access is suitable and that any other constraints are met. For the LOM 2011 the pit design ensures a practical layout for the LOM. A practical pit design was developed for each one of the mining cutbacks from a starter pit up to the final pit. Basically 15 mining cutbacks were designed for Rosario, and 5 for Ujina, each with


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full detailed design including ramps, catch berms, etc. Plan views of the mining phases as designed for the Rosario and Ujina pits are presented in Figure 16-2 and Figure 16-3 respectively.

Figure 16-2: Rosario Mining Phases

Figure 16-3: Ujina Mining Phases


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16.5 Cut-off Grades CMDIC uses a variable cut-off grade strategy as derived using COMET software provided by Strategy Optimisation Systems Ltd. The cut-off is based on the net value before taxes that the material will generate per hour of concentrator operation. This takes into account the variable cost and metallurgical performance of the various ore types processed. The cut-off grades for the 2011 LOM plan are presented in Table 16-7.

Table 16-7: Cut-off Grade by Year Year COG (% CuT) Year COG (% CuT)

2012 0.54% 2037 0.49% 2013 0.75% 2038 0.48% 2014 0.61% 2039 0.41% 2015 0.41% 2040 0.55% 2016 0.48% 2041 0.53% 2017 0.32% 2042 0.54% 2018 0.33% 2043 0.51% 2019 0.54% 2044 0.47% 2020 0.77% 2045 0.49% 2021 0.37% 2046 0.43% 2022 0.51% 2047 0.35% 2023 0.42% 2048 0.30% 2024 0.47% 2049 0.54% 2025 0.30% 2050 0.36% 2026 0.41% 2051 0.41% 2027 0.56% 2052 0.34% 2028 0.43% 2053 0.30% 2029 0.39% 2054 0.30% 2030 0.42% 2055 0.41% 2031 0.47% 2056 0.73% 2032 0.30% 2057 0.30% 2033 0.33% 2058 0.31% 2034 0.36% 2059 0.37% 2035 0.39% 2060 0.37% 2036 0.52%


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16.6 Production Scheduling The mine design phases are triangulated and then used to provide material quantities as input into scheduling software. The long range planning group within the CMDIC Mine Engineering Department developed a LOM plan and a mill feed schedule using only measured and indicated blocks within the ultimate pits. The LOM plan is technically and operationally viable. This LOM mine plan indicates that the reserves reported provide a positive net value. Mine production per year is show in Table 16-8.

Table 16-8: Life-of-Mine Plan

Year Sulphide Material

(Mt) % CuT

Leach Material (Mt)

% CuT

2012 55.0 0.84% 9.3 0.75% 2013 53.5 1.18% 9.4 0.57% 2014 58.5 1.07% 9.5 0.55% 2015 58.4 1.14% 9.5 0.67% 2016 58.4 1.02% 9.6 0.73% 2017 58.4 1.16% 8.9 0.64% 2018 58.4 0.94% 0 0.00% 2019 58.4 0.92% 0 0.00% 2020 58.4 0.94% 0 0.00% 2021 58.4 0.95% 0 0.00% 2022 58.2 0.89% 0 0.00% 2023 58.4 0.96% 0 0.00% 2024 58.4 0.87% 0 0.00% 2025 58.4 0.97% 0 0.00% 2026 58.4 0.90% 0 0.00% 2027 58.4 0.92% 0 0.00% 2028 58.4 0.73% 0 0.00% 2029 58.4 0.80% 0 0.00% 2030 58.4 0.66% 0 0.00% 2031 58.4 0.78% 0 0.00% 2032 58.3 0.78% 0 0.00% 2033 58.4 0.81% 0 0.00% 2034 58.0 0.80% 0 0.00% 2035 58.4 0.83% 0 0.00% 2036 58.4 0.76% 0 0.00% 2037 58.4 0.82% 0 0.00% 2038 58.4 0.71% 0 0.00% 2039 58.4 0.79% 0 0.00% 2040 58.4 0.80% 0 0.00%


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Year Sulphide Material

(Mt) % CuT

Leach Material (Mt)

% CuT

2041 58.4 0.77% 0 0.00% 2042 58.3 0.82% 0 0.00% 2043 58.4 0.74% 0 0.00% 2044 58.4 0.75% 0 0.00% 2045 58.4 0.77% 0 0.00% 2046 58.4 0.81% 0 0.00% 2047 58.4 0.78% 0 0.00% 2048 58.6 0.79% 0 0.00% 2049 58.4 0.79% 0 0.00% 2050 58.3 0.60% 0 0.00% 2051 58.4 0.49% 0 0.00% 2052 58.6 0.60% 0 0.00% 2053 58.4 0.55% 0 0.00% 2054 58.4 0.46% 0 0.00% 2055 58.4 0.66% 0 0.00% 2056 58.6 0.87% 0 0.00% 2057 58.4 0.82% 0 0.00% 2058 58.4 0.51% 0 0.00% 2059 58.4 0.39% 0 0.00% 2060 31.9 0.38% 0 0.00%


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17.0 RECOVERY METHODS 17.1 Ujina Pit Since 2005 Ujina Mine is considered as backup of Rosario feed. A model for the four main geometallurgical units (UGM) in order to predict the global copper recovery was developed during 2011. This new model was developed using the same validated methodology used for the Rosario recovery model.

Currently, Ujina´s material represent 1.03% the total ore fed to Concentrator Plant and 36% in Leaching Plant (mainly related to remaining stocks of Mixed and Oxide material) during the first 10 years of LOM. Due mining Ujina starts in 2030, earlier it’s not needed.

17.2 Rosario Pit After commissioning of the Ujina-Rosario Transition Project in 2004, feed for the concentrator comes mainly from the Rosario pit, a large and very consistent porphyry copper body which averages 0.90% CuT for most of its resources.

During 2011 the available metallurgical model for the Rosario Mine was audited successfully by the external consultant Derek Barrat. This model is based on six geo-metallurgical units (UGM), and reflects the different properties of the rock in terms of treatment capacity, copper and molybdenum recovery, power consumption, steel consumption, as well as the requirement of other relevant inputs to the process.

Briefly, these UGMs have different characteristics regarding mineralization and can be associated to specific areas inside the pit, each one with different metallurgical behaviour. The differentiation is based primarily on the different properties of the rock, such as hardness, abrasiveness of the material, and others (Table 17-1), which are reflected in different rates of treatment, power consumption, steel consumption and other relevant items. In this sense, the impact on the grinding stage is important, since the power cost represents about 40% of the grinding cost, and grinding cost represents about 45% of the total processing cost.

Table 17-1: Treatment capacity and Recovery (P80 of 230 [um]) Unit UGM1 UGM2 UGM3 UGM4 UGM5 UGM6 Total

Mill Throughput t/h 7,987 6,789 7,969 6,883 8,126 8,147 7,669 Copper Recovery % 87.17 81.61 87.89 87.20 83.48 84.56 86.68 Moly Recovery % 48.46 61.41 54.91 60.73 25.85 43.46 53.47

17.3 Rosario Sur I & II Pits During 2011 an updated model for Rosario Sur I&II (ex Dulcinea and La Borracha) was updated and the geo-metallurgical characterization was maintained for support the viability of the process and the expected recovery.

Oxide reserves are reported above the following recovery equation:

RCuT = 85 % x CuSH+/CuT

CuSH+: Acid soluble copper (%)

CuT: Total copper (%)


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18.0 PROJECT INFRASTRUCTURE CMDIC is a operating mine including the open pits (Ujina, Rosario and Capella), oxide plant, sulphide concentrator and a comprehensive infrastructure including a permanent camp. The open pits, together with the facilities at the mine site, are at an elevation of between 3,800m and 4,500m above sea level (m.a.s.l). The complex also includes two concentrate slurry pipelines (203 km length) (8” & 7” diameter). The port facilities, including the Molybdenum recovery plant, Copper concentrate filter plant, concentrate storage facilities and marine terminal, are located at Punta Patache approximately 80 km south of Iquique. The filter plant is nominally at sea level.

The following are key infrastructure items:

18.1 Concentrator Mineral Treatment Rate : 160,000 tonnes per day

Crushing

2 gyratory primary crusher at Rosario Pit : (60” x 113” & New 63”x 114”) and 1 gyratory primary crusher at Ujina Pit (60” x 89”).

Grinding

Lines1&2 each with 1*32’x15’ SAG mill and 2*22’x36’ Ball mills

Line3 with 1*40’x22’ SAG mill and 2*26’x38’ Ball Mills

Flotation : 4,500 cubic feet capacity flotation cells

Concentrate Transport : Two slurry pipelines (8” & 7” OD) to Punta Patache (203km)

Actual Production : 470,000 tonnes of fine copper per year

18.2 Oxide plants Mineral Treatment Rate : 25,000 tonnes per day

Crushing : 3 stage Crushing Circuit

Process : Heap Leaching, Solvent Extraction and Electro-Winning

Production : 40,000 tonnes per year of fine copper in cathode

18.3 Other infrastructure Camp Facilities

2,068 bed capacity at Hotel Pabellón del Inca

7,390 bed capacity at Construction Camp

Transport

232km long, paved access road


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3.1km long airstrip

Port Facilities : Maximum vessel size 60000wmt

Port site Sea : Depth: 16.5 metres

Water Supply : Wells located in the Coposa and Michincha Basin areas

Power Supply

23kV (two circuits) supply from the Northern Grid System (SING)

Heavy Fuel Cogeneration power plant at mine site (45MW)

19.0 MARKET STUDIES AND CONTRACTS 19.1 Markets CMDIC still has some long-term commitments of copper concentrates with overseas smelters: 414,500 DMT during 2012, 380,000 DMT during 2013 and 245,800 DMT during 2014. Aforementioned production tonnages are sold to shareholder companies who requests CMDIC to ship the material to different smelters around the world. During 2015 one hundred percent of CMDIC’s production will be sold to shareholder companies.

CMDIC also produces copper cathodes and molybdenum concentrates materials that are sold exclusively to shareholders companies.

19.2 Contracts All contracts for mine site services, sales of copper concentrates, copper cathodes and molybdenum concentrates, as well as transportation, entered into by CMDIC are negotiated to be within prevailing market terms and conditions.

20.0 ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY IMPACT

The company has a valid Closure Plan which was produced by Golder Associates S.A.. This plan was presented as a letter dated January 9 2009 and was approved by the Mining and Geology National Service (SERNAGEOMIN) under Exempt Resolution N°161 dated February 10 2009. The aforementioned plan was elaborated to comply with the stipulations of Supreme Decree N°72/1985, modified by Supreme Decree N°132/2002, both from the Chilean Mining Ministry.

Knight Piesold S.A. is currently developing consulting work under contract GMS-2011/06 in order to update the Closure Plan. This update is being performed mainly due to the incorporation of new projects which are environmentally approved and to comply with the new national law N° 20,551 (published on November 2011 and that will be valid as of November 11 2012) that regulates Mine Closure.


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21.0 CAPITAL AND OPERATING COSTS Capital and operating cost estimates have been prepared in conjunction with the economic analysis done to verify the LOM Plan prepared to support the new reserves.

As defined by the economic information prepared by the CMDIC Financial team, selling costs were calculated for each material type. Freight and other sales costs were estimated in US$/dmt (dry metric ton of concentrate) and converted to US$/lb of fine Cu according to the corresponding concentrate grade for each UGM. Copper and molybdenum prices for mineral reserve evaluation were set at US$2.30/lb and US$14/lb respectively.

The main parameters used in mineral reserves optimisation are summarized in Figure 21-1 and Figure 21-2 for Ujina and Rosario respectively.

Figure 21-1: Ujina mineral reserve calculation parameters


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Figure 21-2: Rosario mineral reserve calculation parameters

The mining CAPEX is related to mine equipment replacement and/or overhaul. CMDIC considered stay-in-business sustaining CAPEX of 60 MUS$ per year.

There are also sustaining capital of 216 MUS$ that is related to the relocation of 3.5 Km of pipeline, coverage of overland conveyor to allow the construction of the Botadero Sur1 waste dump. This cost will be incurred in year 2032.


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Figure 21-3: Yearly Capital Expenditure (CAPEX)

22.0 ECONOMIC ANALYSIS A summary cash flow analysis based on the production schedule for the Proven and Probable Mineral Reserve was produced and is shown in Table 22-1. The analysis was done using the CMDIC price/cost protocol and is consistent with the stated mineral reserves, and demonstrates a positive Net Present Value (NPV) for Collahuasi. This positive value demonstrates that the Proven and Probable Mineral Reserve as stated, does in fact constitute ore and meets the criteria laid out in the National Instrument 43-101 to classify it as a reportable mineral reserve. The NPV for the project using a discount rate of 8% is 10,103 MUS$.

Table 22-1: Project Net Cash Flow (US$ million, undiscounted) Year Cash Flow Year Cash Flow

2012 887.4 2037 295.6

2013 1,237.9 2038 188.4 2014 1,574.6 2039 262.9 2015 1,747.4 2040 -32.8 2016 1,464.1 2041 205.5 2017 1,343.5 2042 297.4 2018 837.2 2043 227.6 2019 730.3 2044 255.1 2020 612.6 2045 251.9 2021 576.1 2046 335.6 2022 604.0 2047 381.8

0

100

200

300

400

500

600

700

CAPE

X (M

US$)

Production Period

Equipment Others


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Year Cash Flow Year Cash Flow

2023 644.8 2048 329.8 2024 343.6 2049 491.2 2025 716.8 2050 250.4 2026 614.9 2051 -240.5 2027 261.8 2052 2.4 2028 306.2 2053 73.5 2029 444.2 2054 -142.7 2030 186.2 2055 191.2 2031 231.5 2056 942.5 2032 30.9 2057 979,2 2033 336.4 2058 369,5 2034 365.7 2059 59,4

2035 330,3 2060 -207.8

2036 159.7 2061 -122.9

23.0 ADJACENT PROPERTIES No information from adjacent properties has been used in the exploration program or in the estimation of the mineral resource.


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24.0 OTHER RELEVANT DATA AND INFORMATION 24.1 Historical Production Figure 24-1 shows the historical copper production from 2002 to 2011. The production figures are separated by product line (cathodes / concentrate).

Figure 24-1: Historical production for CMDIC's operating deposits

0

100,000

200,000

300,000

400,000

500,000

600,000

FY 2002 FY 2003 FY 2004 FY 2005 FY 2006 FY 2007 FY 2008 FY 2009 FY 2010 FY 2011

Copper cathode t Copper in concentrate t


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25.0 INTERPRETATION AND CONCLUSIONS The December 31, 2011 mineral resources and mineral reserves estimates for Collahuasi were prepared by CMDIC’s personnel and were reviewed by a multidisciplinary team of QPs from Golder. The estimates were reviewed in detail including parameters, assumptions, supporting factual data, procedures and electronic files. The following is a list of general conclusions:

The geology is well understood for the CMDIC copper deposits. The copper and molybdenum mineralization types and extents are well defined, and that knowledge has been integrated into the block models, mining practice and metallurgy.

The quality of the assay data used for block model grade estimates is supported by years of good to excellent reconciliation of material milled to block model grades and tonnages.

The block models were developed using industry-accepted methods. Model estimates reasonably estimate grade and tonnage for the CMDIC deposits.

The Mineral Reserve at CMDIC falls completely within the classification of Proven and Probable Mineral Reserves.

The cut-off grade strategy employed by CMDIC is based on industry-accepted parameters.

Metallurgical expectations are reasonable and based on metallurgical results obtained during production. The increase in production capacity that is considered to take the concentrator from 140ktpd to 160ktpd starting in 2014 is achievable and CMDIC has done considerable amount of process engineering work to support this increase.

Operating cost estimates are reasonable and have been calculated using sound industry-accepted practices with a great deal of input from the ongoing operation.

The assumptions used for cost and revenue estimation are within industry parameters and are valid assumptions for an economic forecast.

Golder considers that the December 31, 2011 mineral resources and mineral reserves estimates for CMDIC have been prepared in compliance with the disclosure and reporting requirements set forth in the current Canadian Securities Administrator’s National Instrument 43-101 and Companion Policy 43-101CP.

26.0 RECOMMENDATIONS Collahuasi is a world class and mature operating mine which is currently developing a strategic growth plan. The mineral resource and mineral reserve estimation work is carried out at the highest standards by CMDIC’s professionals. The QPs have no further recommendations with regards to exploration activities or engineering studies related to the matters discussed in this Technical Report.


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27.0 REFERENCES JORC, 2004, Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (The JORC Code). Prepared by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists and Minerals Council of Australia (JORC), effective 17 December 2004.

CMDIC, November 2005, Procedimiento específico gerencia geología - Superintendencia de Exploraciones: Procedimiento muestreo de pozos de exploracion e infill - VPDPC004, 7P.

CMDIC, November 2005, Manual de Estándares y P.N.R. - Superintendencia de Exploraciones: Procedimiento corte de testigos - VPDP005, 9p.

CMDIC, June 2005, Procedimiento Específico Vicepresidencia de Desarrollo Gerencia de Geología-VPD: Confección de Despachos de Preparación de Muestras y/o Análisis con Inserción de Muestras de Control - VPDPC007, 11p.

CMDIC, April 2007, Actualización Modelo Rosario: Internal report, 151p.

CMDIC, November 2003, Rosario resource model: Internal report, 78p.

Bisso, C.B., Duran, M. And Gonzales, A.A., 1998, Geology of the Ujina and Rosario copper deposits Collahuasi district, Chile, in Porter, T.M., ed., Porphyry and hydrothermal copper and gold deposits: A global perspective, Adelaide, PGC Publishing, p. 217-232.

Lee, A.W., 1994, Evolution of the Rosario copper-molybdenum porphyry deposit and associated copper-silver vein system, Collahuasi district, I Region, northern Chile: Unpublished MSc thesis, Kingston, Ontario, Canada, Queen’s University, 75p.

Masterman, G.J., 2003, Structural and geochemical evolution of the Rosario Cu-Mo porphyry deposit and related Cu-Ag veins, Collahuasi district, northern Chile: Unpublished PhD dissertation, Tasmania, Australia, University of Tasmania, 253p.

Masterman, G.J., Cooke, D.R., Berry, R.F., Clark, A.H., Archibald, D.A., Mathur, R., Walshe, J.L. and Duran, M., 2004; 40Ar/39Ar and Re-Os geochronology of porphyry copper-molybdenum deposits and related copper-silver veins in Collahuasi district, northern Chile,: Economic Geology, v. 99, p. 673-690.

Masterman, G.J., Cooke, D.R., Berry, R.F., Walshe, J.L., Lee, A.W. and Clark, A.H., 2005, Fluid chemistry, structural setting and emplacement history of the Rosario Cu-Mo porphyry and Cu-Ag epithermal veins, Collahuasi district, northern Chile: Economic Geology, v. 100, p. 835-862.

Munchmeyer, C., Hunt, J.P. and Ware, H., 1984, Geología del Distrito de Collahuasi y del pórfido cuprífero Rosario: Internal report: Santiago, Compañía Doña Inés de Collahuasi, 84p.

Pitard, F., June 2004, Review of sampling systems and sampling practices at the Cia. Minera Doña Inés de Collahuasi Scm: Internal report, 38p.

Pitard, F., December 2004, Review of sampling systems and sampling practices at the Cia. Minera Doña Inés de Collahuasi Scm, Phase 2: Internal report, 45p.


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Shaw, William J., 1997, Validation of Sampling and Assaying Quality for Bankable Feasibility Studies. In: The Resource Database Towards 2000, Wollongong, 16 May, AusIMM Melbourne, p. 41-19.

Golder Associates S.A., 2012, Auditoría de Recursos Rosario Sur I, II & III, Compañía Minera Doña Inés de Collahuasi, Technical Report, 180p.

Golder Associates S.A., 2010, Rosario Oeste Mineral Resources Audit, Compañía Minera Doña Inés de Collahuasi, Technical Report, 100p.

Golder Associates S.A., 2009, Audit of Mineral Resources and Ore Reserves for Compañía Minera Doña Inés de Collahuasi, 299p.

Golder Associates S.A., 2008, Review of Resources and Reserves, Collahuasi, Region I of Iquique, Chile, 137p.


29 March 2012 Report No. 1292154001

28.0 REPORT SIGNATURE PAGE

Marcelo Godoy, PhD, AusIMM (CP) Principal Ore Evaluation Services

Juan Pablo González, Chilean Mining Commission Senior Mining Engineer

Ronald Turner , AusIMM (CP) Senior Resource Geologist

MG/RT/rm

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29 March 2012 Report No. 1292154001

APPENDIX A Certificates of Qualified Persons

CERTIFICATES OF QUALIFIED PERSON Marcelo Godoy, PhD As principal author of the Technical Report entitled “Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Chile”, dated 29 March 2012 (the “Report”), on the Collahuasi Copper Mine of Compañia Minera Doña Inés de Collahuasi (CMDIC), I hereby make the following statements:

• My name is Dr Marcelo Godoy and my title is Principal, Ore Evaluation Services with the firm of Golder Associates S.A., with a business address at Magdalena 181 piso 3, Las Condes, Santiago, Chile. My residential address is Onofre Jarpa 9476, La Reina, Santiago, Chile.

• My formal education qualifications include PhD (Doctor of Philosophy) in Mining Engineering from the University of Queensland (2002), MSc (Master of Science) in Mineral Economics from the Federal University of Rio Grande do Sul, Brazil and BEng (Bachelor of Engineering) in Mining from the Federal of Rio Grande do Sul (1995).

• I am a practising Geostatistician and Mining Engineer and a Chartered Professional and Member in good standing of the Australasian Institute of Mining and Metallurgy (AusIMM).

• I have practiced my profession continuously since 1996.

• I have read the definition of “qualified person” set out in National Instrument 43-101 (NI 43-101) and certify that, by reason of my education, affiliation with a professional association (as defined in NI 43-101) and past relevant work experience, I fulfil the requirements to be a “Qualified Person” for the purpose of NI 43-101.

• My relevant experience with respect to the Collahuasi Copper Mine includes over 8 years experience in Mineral Resource and Mineral Reserve estimation related to copper porphyry deposits in Chile and over 15 years experience in grade control, sampling studies and evaluation of mining projects.

• I have had prior involvement with the Property that is the subject of the Technical Report, which is related to independent audits of Mineral Resources and Mineral Reserves carried out between 2007 and 2011.

• I have reviewed the work carried out by CMDIC and their agents for the estimation of Mineral Resources and Mineral Reserves for the Collahuasi Copper Mine. I am also responsible for the preparation of the Sections 1-6, 13-14, 18-20 and 23-27 and take responsibility as a principal author of this Technical Report titled “Mineral Resources and Mineral Reserves, Collahuasi

Copper Mine, Chile”, dated 29 March 2012. I have personally visited the property from 3 to 7 December 2007.

• As of the date of this Certificate, to my knowledge, information and belief, the section of this Technical Report for which I am responsible contain all scientific and technical information that is required to be disclosed to make the Technical Report not misleading.

• I am independent of the Issuer as defined by Section 1.5 of the Instrument.

• I have read National Instrument 43-101 and the sections in this Technical Report have been prepared in compliance with National Instrument 43-101 and Form 43-101F1.

Signed and dated this 29th day of March, 2012 at Santiago, Chile

___________________________ Marcelo Godoy, PhD, MAusIMM (CP) Principal, Ore Evaluation Services

CERTIFICATES OF QUALIFIED PERSON Ronald Turner As author of the Technical Report entitled “Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Chile”, dated 29 March 2012 (the “Report”), on the Collahuasi Copper Mine of Compañia Minera Doña Inés de Collahuasi (CMDIC), I hereby make the following statements:

• My name is Ronald Tuner and my title is Senior Resource Geologist with the firm of Golder Associates S.A., with a business address at Magdalena 181 3rd floor, Las Condes, Santiago, Chile. My residential address is Simón González 7761 R, La Reina, Santiago, Chile.

• My formal education qualifications include Bachelor of Science in Geology from the Universidad de Concepción (1993).

• I am a practising Geologist and a Chartered Professional and Member in good standing of the Australasian Institute of Mining and Metallurgy (AusIMM).



• My relevant experience with respect to the Collahuasi Copper Mine includes over 15 years experience in project development, mining operations and Mineral Resource estimation related to copper porphyry deposits in Chile.


• I have reviewed the work carried out by CMDIC and their agents for the estimation of Mineral Resources for the Collahuasi Copper Mine. I am also responsible for the preparation of the Sections 7-12 and take responsibility as an author of this Technical Report titled “Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Chile”, dated 29 March 2012. I have personally visited the property from 27 and 28 of January 2010.





___________________________ Ronald Turner, MAusIMM (CP) Senior Resource Geologist, Ore Evaluation Services

CERTIFICATES OF QUALIFIED PERSON Juan Pablo González As author of the Technical Report entitled “Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Chile”, dated 29 March 2012 (the “Report”), on the Collahuasi Copper Mine of Compañia Minera Doña Inés de Collahuasi (CMDIC), I hereby make the following statements:

• My name is Juan Pablo González and my title is Senior Mining Engineer with the firm of Golder Associates S.A., with a business address at Magdalena 181 3rd floor, Las Condes, Santiago, Chile. My residential address is Magnolio 5607, Peñalolén, Santiago, Chile.

• My formal education qualifications include MBA (Master of Business and Administration), Universidad Diego Portales, (2002) Chile and BSc (Bachelor of Science) in Mining Engineering, Universidad de Santiago de Chile, (1992).

• I am a practising Mining Engineer, Registered Member of Chilean Mining Commission, Member of the Australasian Institute of Mining and Metallurgy (MAusIMM) and Member of the Chilean Institute of Mining Engineering (IIMCH).



• My relevant experience with respect to the Collahuasi Copper Mine includes over 17 years experience in Mineral Reserves estimation , computerized mine planning systems and technical engineering activities related to a variety of commodities (in nickel, copper, gold and iron and manganese ore) and many projects in South America.


• I have reviewed the work carried out by CMDIC and their agents for the estimation of Mineral Reserves for the Collahuasi Copper Mine. I am also responsible for the preparation of the Sections 15-17 and 21-22, and take responsibility as an author of this Technical Report titled “Mineral Resources and Mineral Reserves, Collahuasi Copper Mine, Chile”, dated 29 March 2012. I have personally visited the property from 3 to 7 December 2007.





___________________________ Juan Pablo González, MAusIMM (CP) Senior Mining Engineer, Ore Evaluation Services

Golder Associates S.A. Av.11 de Septiembre 2353 - Piso 2 Providencia Santiago Chile T: +56 (2) 594 2000

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