amulsar gold project - lydian · lydian international ltd. commissioned snc-lavalin to conduct a...

Amulsar Gold Project

Crushing Circuit

Trade-off Study

Document No: Rev Date: Page

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REVISION CONTROL

Issued for Internal Coordination

Issued for use

REVISION HISTORY

Revision Pages Revised Remarks

PB All Included Client’s Comments. Adjusted Capex battery limits to match the KDE Capex estimate.

PC All Various minor corrections.


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DISCLAIMER

This document contains the expression of the professional opinion of SNC-Lavalin

Australia Pty Ltd (“SLA”) as to the matters set out herein, using its professional

judgment and reasonable care. This document is written solely for the purpose stated

in the Agreement and for the sole and exclusive benefit of the Client, whose remedies

are limited to those set out in the Agreement. This document is meant to be read as a

whole and sections or parts thereof should thus not be read or relied upon out of

context.

SLA has, in preparing the cost estimates, followed methodology and procedures and

exercised due care consistent with the intended level of accuracy using its professional

judgment and reasonable care and is thus of the opinion that there is a high probability

that actual costs will fall within the specified error margin. However, no warranty

should be implied as to the accuracy of estimates.

Unless expressly stated otherwise, assumptions, data and information supplied by, or

gathered from, other sources (including the Client, other consultants, testing

laboratories and equipment suppliers, etc.) upon which SLA’s opinion as set out herein

is based have not been verified by SLA and SLA makes no representation as to its

accuracy and disclaims all liability with respect thereto.

To the extent permitted by law, SLA disclaims any liability to third parties in respect of

the publication, reference, quoting, or distribution of this report or any of its contents to

and reliance thereon by any third party.


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TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY .................................................................................... 7

2.0 INTRODUCTION ................................................................................................ 9

3.0 DEFINITIONS AND GLOSSARY ..................................................................... 11

4.0 SCOPE OF STUDY AND METHODOLOGY .................................................... 17

4.1 Scope of Work ............................................................................................. 17

4.2 Exclusions ................................................................................................... 19

4.3 Battery Limits .............................................................................................. 19

4.4 Process Streams ......................................................................................... 20

4.4.1 Inputs ............................................................................................................ 20

4.4.2 Outputs ......................................................................................................... 20

4.4.3 Reagents ...................................................................................................... 20

4.4.4 Utilities .......................................................................................................... 20

4.5 Study Methodology ..................................................................................... 20

4.5.1 Process Design Package .............................................................................. 20

4.5.2 Design Basis ................................................................................................. 21

4.5.3 Process Design ............................................................................................. 21

4.5.4 Engineering Design ....................................................................................... 22

4.5.5 Procurement ................................................................................................. 23

4.5.6 Capital Cost Estimate .................................................................................... 23

5.0 OPTIONS ANALYSIS ....................................................................................... 24

5.1 Circuit Options Discussion ........................................................................ 25

6.0 PROCESS PLANT DESCRIPTION .................................................................. 31

6.1 Area 2110 Primary Crushing ...................................................................... 32

6.2 Area 2120 Secondary Screening ................................................................ 35

6.3 Area 2130 Secondary Crushing ................................................................. 36

6.4 Area 2140 Tertiary Screening ..................................................................... 37

6.5 Area 2150 Tertiary Crushing....................................................................... 38

6.6 Area 2160 Product Loadout ........................................................................ 39

6.7 Area 2900 Plant Heating ............................................................................. 39

6.8 Fuel Supply.................................................................................................. 40

6.9 Personnel Accommodation and Transport ............................................... 40

6.10 Process Buildings and Facilities ............................................................... 40

7.0 CAPITAL COST ESTIMATE ............................................................................ 41


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7.1 Equipment ................................................................................................... 42

7.1.1 Bulk Earthworks ............................................................................................ 42

7.1.2 Plant Buildings .............................................................................................. 42

7.2 Structural - Concrete .................................................................................. 42

7.3 Structural – Steelwork ................................................................................ 42

7.4 Mechanical................................................................................................... 43

7.5 Piping ........................................................................................................... 43

7.6 Electrical ...................................................................................................... 43

7.7 Instrumentation ........................................................................................... 43

7.8 Miscellaneous Items ................................................................................... 43

7.9 Indirect Costs .............................................................................................. 43

7.10 EPCM Costs ................................................................................................. 43

7.11 Estimate Accuracy ...................................................................................... 44

7.12 Contingency ................................................................................................ 44

7.13 Battery Limits .............................................................................................. 44

7.14 Estimate Exclusions ................................................................................... 44

7.14.1 Commissioning ............................................................................................. 45

8.0 ESTIMATE COMPARISON .............................................................................. 46

APPENDIX A CRUSHING CIRCUIT OPTIONS ............................................................ 50

APPENDIX B CAPITAL COST ESTIMATE .................................................................. 51

APPENDIX C PROCESS DESIGN CRITERIA .............................................................. 52

APPENDIX D PROCESS FLOW DIAGRAMS .............................................................. 53

APPENDIX E PIPING AND INSTRUMENTATION DIAGRAMS ................................... 54

APPENDIX F MECHANICAL EQUIPMENT LIST ......................................................... 55

APPENDIX G ELECTRICAL LOAD LIST ..................................................................... 56

APPENDIX H PIPING, LINE AND VALVE LIST ........................................................... 57

APPENDIX I SINGLE LINE DIAGRAMS ...................................................................... 58

APPENDIX J LAYOUT AND PERSPECTIVE DRAWINGS .......................................... 59


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LIST OF TABLES

Table 3-1 Abbreviations, Acronyms and Terms ........................................................................ 11

Table 4-1 Study Deliverable List ............................................................................................... 17

Table 4-2 Crushing and Screening Plant Design Basis – Key Parameters ............................... 21

Table 5-1 Circuit Configuration Options Summary .................................................................... 24

Table 5-2 Installed vs Drawn Power - Crusher Summary ......................................................... 30

Table 7-1 Capital Cost Estimate Summary ............................................................................... 41

Table 8-1 Estimate Inclusions Comparison ............................................................................... 46

Table 8-2 Capital Cost Estimate Comparison ........................................................................... 47

LIST OF FIGURES

Figure 2-1 Amulsar Project Locality Map .................................................................................... 9

Figure 5-1 Option 1 Flowsheet ................................................................................................. 26

Figure 5-2 Option 10 Flowsheet ............................................................................................... 28

Figure 6-1 Crushing and Screening Plant Process Flow Diagram ............................................ 31

Figure 6-2 Crushing and Screening Plant Overall Layout ......................................................... 32

Figure 6-3 Primary Crusher Plant ............................................................................................. 32

Figure 6-4 Primary Crusher Plant ............................................................................................. 34

Figure 6-5 Example of a Primary Gyratory Crusher Installation ................................................ 34

Figure 6-6 Secondary & Tertiary Screening Plant ..................................................................... 35

Figure 6-7 Example of a Cone Crusher .................................................................................... 36

Figure 6-8 Example of a Double-Deck Banana Screen............................................................. 37

Figure 6-9 Secondary & Tertiary Crushing Plant....................................................................... 38

Figure 6-10 Example of a Typical Industrial Hot Water Boiler ................................................... 39

Figure 6-11 Example of a Typical Industrial Heater .................................................................. 40


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1.0 EXECUTIVE SUMMARY

Lydian International Ltd. commissioned SNC-Lavalin to conduct a crushing circuit

trade-off study for the Amulsar Gold Project located in Armenia. A feasibility study was

conducted earlier in 2012 for this project by KD Engineering.

The original concept was based on developing the project in two phases, each being

capable of crushing and screening 5 Mtpa of gold and silver bearing ore in preparation

for heap leaching. Following the feasibility study Lydian wished to examine an

alternative option of utilising a processing rate of 10 Mtpa from the start and as the

base case production scenario. To improve project NPV the proposed plant would be

designed to process 10 Mtpa of the ROM ore to produce a crushed product with the

particle size of less than 12 mm in preparation for heap leaching and the subsequent

recovery of gold.

The trade-off study summarised in this report aimed to:

• Conduct modelling of various configuration of the crushing and screening plant.

• Provide a summary of the selected equipment and operating parameters for each

option studied.

• Select a single option to be used as a basis for the development of the capital cost

estimate (CAPEX).

Ten different crushing and screening plant configurations were assessed and

compared. The options study examined various sizes and numbers of equipment used

in each of the three crushing and the associated screening stages. Option 10 was

selected for the development of the detailed capital cost estimate. This option consists

of one primary gyratory crusher (62/75), two secondary double-deck banana vibrating

screens, two secondary MP800st (or equivalent) cone crushers, three tertiary double-

deck banana vibrating screens and three tertiary MP800sh (or equivalent) cone

crushers. At this level of comparison, and following discussions with vendors, none of

the options considered appeared to have significant advantage in terms of operating

cost.

The proposed circuit configuration is expected to provide a robust plant with suitable

catch up and sprint capability to be able to cater for the adverse weather conditions.

Given the nature of heap leaching operations, the location of the project and the

climatic conditions in the area these factors are expected to be key components in

achieving the targeted plant throughput.


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The capital cost estimate for the selected crushing and screening plant, as per specified

battery limits, inclusions and exclusions, is provided in the following table.

Area Area Total Cost (USD) % of Cost

Crushing & Screening 71,442,822 50.4

Services 12,765,293 9.0

Sub-Total Direct Costs 84,208,115 59.4

Plant Wide Earthworks 10,861,910 7.7

EPCM 14,500,0000 10.2

Growth 8,800,000 6.2

Contingency 19,500,000 13.8

Spares 1,410,000 1.0

Vendor Reps 1,500,000 1.05

First Fill 1,000,000 0.7

Sub-Total Indirect Costs 57,571,910 40.6

Grand Total 141,780,025 100.0

The level of accuracy of the estimate obtained in this study is of the magnitude of

±15%.

It should be noted that this trade-off study was focused on the crushing and screening

plant component of the project. Any considerations associated with the relative location

of the mining area and heap leaching pads were outside of the scope of this study. As

such these factors may present potential opportunity for further optimisation of the plant

configuration.


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2.0 INTRODUCTION

The Amulsar gold project is located 170 km south of Armenia's capital Yerevan on the

border between the provinces (Marz) of Vayots Dzor and Sunnik. Lydian International

holds two Mineral Exploration Licences and a mining licence for the Artavasdes and

Tigranes open pit at Amulsar, through its 100% owned Armenian subsidiary Geoteam

CJSC. The Amulsar licences cover a total of 65 km2. The location of the project is

illustrated in Figure 2-1 below.

Figure 2-1 Amulsar Project Locality Map

Lydian International conducted a feasibility study carried out by KD Engineering in

Tucson, Arizona, USA. Various references are made in this document to this study.

The feasibility study was based on the plant concept consisting of two crushing and


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screening trains in parallel, with each train being capable of processing 5 Mtpa. The

proposed project would be brought online in two phases, commencing with a single

production train of 5 Mtpa and increasing to 10 Mtpa with the addition of another

production train in Year 4.

Following the above feasibility study completed by KD Engineering Lydian wished to

investigate an alternative option of utilising the ore processing rate of 10 Mtpa as a

base case production scenario. SNC-Lavalin Australia were commissioned to provide

a trade-off study to investigate the 10 Mtpa crushing and screening circuit option. The

study was based on evaluation and comparison of various configurations of the

crushing and screening circuit and developing engineering details and a cost estimate

for a selected configuration. The proposed project would be designed to process

10 Mtpa of the ROM ore to produce a crushed product with a P80 of 12 mm in

preparation for heap leaching and the subsequent recovery of doré.

The key objectives of the trade-off study were:

• To conduct modelling of various configuration of the crushing and screening plant.

• To provide a summary of the selected equipment and operating parameters for

each option studied.

• To select a single option to be used as a basis for the development of the capital

cost estimate.

This report provides a summary of the findings resulting from the trade-off study and a

capital cost estimate for the selected crushing and screening plant configuration.


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3.0 DEFINITIONS AND GLOSSARY

Various abbreviations, acronyms and terms used throughout this report are explained in

Table 3-1.

Table 3-1 Abbreviations, Acronyms and Terms

Abbreviation Explanation

C/I Civil and Infrastructure

CIF Cost Insurance Freight

CMMS Central Maintenance Management System

CPPC Contractor Progress Payment Certificate

CPU Central Processing Unit

CWi Crushing Work Index

CSS Closed Side Setting (Crusher Setting)

DCN Data Communication Network

DDU Delivered Duties Unpaid

DFS Definitive Feasibility Study

DOL Direct On-line

dP Differential Pressure

Dt/h Unit of mass throughput, dry tonnes per hour

E East

E/I Electrical and Instrumentation

EIA Environmental Impact Assessment

EPCM Engineering Procurement and Construction Management

EPB Emergency Push Button

ER Emergency Response


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ESIA Environmental Statement and Impact Assessment

Ethernet A family of frame-based computer network technologies for local area networks

Excel™ Software application, Microsoft® Excel™

GST Goods and Services Tax

H Unit of time, hour

Ha Unit of area, hectare

HART Highway Addressable Remote Transducer

HV High Voltage

HVAC Heating Ventilation Air Conditioning

IEC International Electro-technical Commission

I/O Input/Output

IR Infrared

ISA Instrumentation Systems and Automation Society

ISO International Organization for Standardization

IT Information Technology

J/m3K Unit of heat capacity, joules per cubic metre degree Kelvin

Km Unit of length, kilometre

kN Unit of force, kilonewton

kPa Unit of pressure, kilopascal

kV Unit of electromotive force, kilovolt

kWh/t Unit of power consumption, kilowatt per hour per tonne

L Unit of volume, litre

LAN Local Area Network


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LCB Local Control Board

LME London Metal Exchange

LOA Letter of Award

LV Low Voltage

M Unit of length, metre

m/s Unit of speed, metres per second

mA Unit of current, milliamp

MCC Motor Control Centre

MetSim Commercially available mass and energy balancing software

mg/m3 Unit of concentration, milligrams per cubic metre

Min Unit of time, minute

MIS Management Information System

Mm Unit of length, millimetre

MRR Materials Receiving Report

MPa Unit of pressure, megapascal

MSHA Mines Safety and Health Administration

MSDS Material Safety Datasheet

Mtpa Unit of mass throughput, mega (10 6) tonnes per annum

MTO Materials Take-Off

MV Medium Voltage

mV Milivolts

MW Unit of power, megawatt

N North


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NB Nominal Bore

NDT Non-Destructive Testing

NFPA National Fire Protection Association

NL/min Unit of volumetric flow rate, normal litres per minute

Nm3/h Unit of volumetric flow rate, normal cubic metres per hour

NPV Net Present Value

On-Stream Factor Measure of time, expressed as a percentage, used to define the overall time equipment is expected to be operational

OCS Operator Control Station

OD Outside Diameter

P80 Size at which 80 per cent of the mass of a sample will pass a screen

P100 Size at which 100 per cent of the mass of a sample will pass a screen

P&ID Piping and Instrumentation Diagram

PAR Procurement Action Request

PC Personal Computer

PCS Plant Control System

PFC Power Factor Correction

PFD Process Flow Diagram

PID Proportional Integral Derivative

PIP Project Implementation Plan

PLC Programmable Logic Controller

PM Preventative Maintenance

PM+ SNC-Lavalin International proprietary project management tool


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Project Amulsar Crushing Plant Options Study

PO Purchase Order

PPC Progress Payment Certificate

PPE Personal Protective Equipment

PRA Project Risk Analysis

PT 100 Temperature sensor made from platinum

PVC Poly Vinyl Chloride

Qf Heat loss, measured in Watts

QA/QC Quality Assurance/Quality Control

QMS Quality Management System

RCM Reliability Centred Maintenance

RFI Request for Information

RFQ Request for Quotation

ROM Run-of-Mine

RTD Resistance Temperature Detector

SCADA Supervisory Control and Data Acquisition

SCP Slave Processor Communication Program

SIL Safety Integrity Level

SNC-Lavalin SNC-Lavalin Pty Ltd, member of SLI

SLI SNC-Lavalin Inc

SOP Standard Operating Procedure

SQL Structured Query Language

T Unit of mass, metric tonne


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t/a Unit of mass throughput, tonnes per annum

t/h Unit of mass throughput, tonnes per hour

t/t Unit of concentration, tonnes per tonne

TPL Third Party Logistics Provider

TV Television

µm Unit of length, micron

µs Unit of time, microsecond

VAC Unit of electromotive force, Volts, AC Power

VDU Video Display Unit

V/h Unit of turnover, volume per hour

VVVF Variable Voltage Variable Frequency

Word Software application, Microsoft® Word ™

W/m2/°C Unit of heat transfer, watts per unit area per degree Celsius

w/w Proportion of one unit compared to another on a weight basis

WBS Work Breakdown Structure


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4.0 SCOPE OF STUDY AND METHODOLOGY

4.1 Scope of Work

The following table provides a list of deliverables for the Amulsar Gold Project trade-off

study.

Table 4-1 Study Deliverable List

Item Document Number

Process & General

Study Report 140192-30RF-I-0001

Process Design Criteria 140192-0000-49EC-0001

Mass and Water Balance 140192-0000-49EB-0001

(included in drawing no.: 140192-2000-49D1-0001)

Crushing Circuit Options Summary 140192-0000-49EB-0002

Drawings

Process Flow Block Diagram 140192-2000-49D3-0001

Plant Flow Diagram – Schematic 140192-2000-49D3-0002

Stream Flow Data 140192-2000-49D1-0001

Primary Crushing 140192-2110-49D1-0001

Secondary Screening 140192-2120-49D1-0001

Secondary Crushing 140192-2130-49D1-0001

Tertiary Screening 140192-2140-49D1-0001

Tertiary Crushing 140192-2150-49D1-0001

Product Loadout 140192-2160-49D1-0001

Building Heating - hot water supply 140192-2960-49D1-0001

Building Heating 140192-2960-49D1-0002

Primary Crushing 140192-2110-49D4-0001


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Secondary Screening - Sheet 1 140192-2120-49D4-0001

Secondary Screening - Sheet 2 140192-2120-49D4-0002

Secondary Crushing - Sheet 1 140192-2130-49D4-0001

Secondary Crushing - Sheet 2 140192-2130-49D4-0002

Tertiary Screening - Sheet 1 140192-2140-49D4-0001



Tertiary Crushing - Sheet 1 140192-2150-49D4-0001



Product loadout 140192-2160-49D4-0001

Building heating - hot water supply 140192-2960-49D4-0001

Building heating - Sheet 1 140192-2960-49D4-0002



Engineering

Mechanical Equipment List 140192-2000-45EL-1001

Electrical Load List 140192-6100-47EL-0001

Site layout – Plan 140192-2000-4LD1-0001

Site Layout – Perspective 140192-2000-4LD1-0002

Primary Crushing Building - Perspective 140192-2000-4LD1-0003

Secondary and Tertiary Screening Building - Perspective 140192-2000-4LD1-0004

Secondary and Tertiary Crushing Building - Perspective 140192-2120-4LD1-0005


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Civil Layout - Plan 140192-2000-41D2-0001

Power Distribution Single Line Diagram – Sheet 1 140192-6100-47EL-0001



Estimating

Capital Cost Estimate 140192-0000-33KB-0001

Basis of Estimate 140192-0000-33KB-0002

4.2 Exclusions

The following items were excluded from the scope of work:

• Metallurgical test work

• Mining

• Geology

• Infrastructure

• Owner’s costs

• Project Financial Modelling

• Survey, geotechnical, hydrology, hydrogeology and site based investigations.

4.3 Battery Limits

The battery limits for the circuit studied were defined as follows:

• Inlet to the primary crusher

• Outlet of the tertiary crushing to the fine ore transfer conveyor

• Air, water and power defined as ‘over the fence’ and the battery limit conditions

stated.

There was some discussion between SNC-Lavalin and Lydian International following

the issue of the formal proposal regarding the back-end of the plant battery limit. It was

agreed that for the purpose of this study the effective battery limit will be the discharge

of the tripper conveyor feeding the crushed ore surge bin. SNC-Lavalin have proposed

two shuttle conveyors in lieu of the tripper conveyor to feed the crushed ore bins prior


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to the overland conveyor. However, for the capital cost estimate, in order to enable a

direct comparison with the KD Engineering estimate, the KDE’s estimate for the fine

ore bin and the lime silo were added to the SNC-Lavalin estimate to ensure that the

same battery limits are covered.

4.4 Process Streams

4.4.1 Inputs

• ROM ore.

• Raw water at a nominated point on the crushing plant boundary.

• Power at a nominated point on the crushing plant boundary.

4.4.2 Outputs

• Fine ore to the product loadout.

• Exhaust and vent gas/dust streams terminate at the limit of the building or

process equipment discharge line.

4.4.3 Reagents

The reagent associated with the part of the plant under consideration of this study is

lime. It was not included in the scope of the trade-off study, but the cost of the storage

silo and the associated equipment was added to the estimate using the KD

Engineering design and cost to ensure that both estimates cover the same battery

limits.

4.4.4 Utilities

• Electrical power at the HV inlet terminals of the plant distribution transformer for

electrical reticulation.

• Water supply (fresh, potable, fire, safety shower supply, etc.) to be defined.

• Storm water drains were not included in the scope of this study.

4.5 Study Methodology

4.5.1 Process Design Package

A number of crushing and screening circuit configurations were reviewed to determine

an optimum design to take forward to the engineering phase of the study. The range of

configurations and advantages and disadvantages of each option were reviewed with

Lydian in reaching a decision.

The crushing circuit was based on an engineering design produced by SNC-Lavalin

and presented in this report. The design includes the following information:


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• Block Flow Diagram

• Process Flow Diagrams

• Development of a mass balance for the proposed flowsheet

• Development of process design criteria

• Equipment list including equipment sizing

• Design calculations as required

4.5.2 Design Basis

The key design criterion provided by Lydian and used to guide the design philosophy

was the ore processing rate of 10 Mtpa. The primary operating parameters used in the

design are summarised in Table 4-2 below. The process design criteria document

number 140192-0000-49EC-0001 containing a full set of the relevant information is

appended for reference.

Table 4-2 Crushing and Screening Plant Design Basis – Key Parameters

Parameter Value Unit

Plant throughput rate, nominal 10 000 000 t/a

Plant throughput rate, design 11 500 000 t/a

Plant throughput rate, nominal 1 565 t/h

Plant throughput rate, design 1 800 t/h

Operating days per annum 355 days

Operating days per week 7 days

Operating hours per day 24 hours

Operating hours per annum (effective, feed on) 6 390 hours

Crushed ore particle size (P80) 12 mm

4.5.3 Process Design

Following discussions with Lydian on the various aspects of the flowsheet development

and the final circuit configuration selection, the proposed crushing plant design was

further modelled using Metsim software. The process design criteria were developed

based on SNC-Lavalin’s in-house database, information provided by the Client, and


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Bruno modelling results. In completing preliminary equipment design, the critical

design parameters, such as flows and compositions of streams, were compared with

typical plant practice to ensure that where assumptions have been made, that these

are reasonable. A summary of the critical operational parameters is shown at the start

of the design criteria.

The material balances, which incorporate solution and solids flows, were used for

sizing of equipment, bins, pumps and tanks. The mass balance is presented in the

Appendix D with flows relating to the stream numbers depicted on the stream data

PFD. The mass balance focuses on mass flows of solids within the overall flowsheet.

Preliminary and conceptual Piping and Instrumentation Diagrams (P&IDs) were

developed as part of this study. Piping, instrumentation and valve requirements were

also determined.

4.5.4 Engineering Design

The following preliminary information was generated in sufficient detail for a capital cost

estimate to the specified accuracy to be prepared:

• Mechanical Equipment List.

• Electrical load list, developed from the Mechanical Equipment List and vendor

data, used to calculate power consumption.

• Process Flow Diagrams.

• Design Calculations.

• General Arrangement Drawings.

• Bulk Materials Takeoffs from the plant model.

• Datasheets for major equipment.

4.5.4.1 Climatic Conditions

The climatic conditions in the area necessitated the following considerations:

• Crusher and screening buildings are enclosed and heated via hot water

system/hot air fan assisted heat exchangers.

• Access and egress between the crushing and screening plants undertaken via

enclosed walkways located in conveyor gantries to provide all weather access

within the plant.

4.5.4.2 Earthworks

The proposed plant is located in a high seismic zone, hence foundations for the

buildings and equipment must be founded on competent surfaces, significant cutting

into the rock faces to ensure competent surfaces will be necessary.


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Earthworks on this project will represent a significant capital cost. SNC-Lavalin at this

juncture have not been provided with complete survey details as indicated in the

feasibility study layouts undertaken for the project to date.

For comparison purposes a preliminary earthworks model has been developed which

indicates the proposed new layout of the crushing and screening plant will reduce the

cut and fill requirements by approximately 10% when compared with the previous

feasibility study layout.

Base data – KD’s scheme for crushing and screening plants cut to fill ratio 12.8:1,

current 11.5:1. The potential for a further reduction of the cut requirements exists with

extensive modification of the earthworks, hence providing a more balanced cut to fill

ratio, however this will require re-orientation of the plant and extensive engineering to

determine the cost benefit, hence currently these factors have not been considered in

this phase of the project development.

4.5.5 Procurement

Procurement packages were developed from the Mechanical Equipment List.

Datasheets were prepared for major equipment packages. Multiple source bids were

sought for major equipment packages from vendors known to provide cost competitive

bids for the equipment. For minor equipment packages, single source bids were

sought. Australian vendors only were approached but with representatives in Europe

where appropriate.

4.5.6 Capital Cost Estimate

The methodology employed in generating the capital cost estimate, including direct and

indirect costs for the project is provided in Section 7. On this basis, capital costs within

the specified level of accuracy were generated.


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5.0 OPTIONS ANALYSIS

The first step in the trade-off study was to model and analyse various circuit

configuration options. Different circuit configurations and equipment sizes as well as

equipment numbers were considered.

The simulations were performed using Metso’s Bruno software and as such the

equipment selection shown for comparative purposed is based on Metso equipment.

However, this does not indicate that SNC-Lavalin recommends using Metso equipment

and other crusher and screen vendors were invited to provide equivalent equipment

prices for the purpose of this study. An equivalent crusher and/or screen size would be

used where appropriate.

The details of all of the evaluated options are provided in the Appendix A. A summary

showing the major equipment in each option is presented in Table 5-1.

Table 5-1 Circuit Configuration Options Summary

Option Primary

Crushing Secondary Crushing

Secondary Screening

Tertiary Crushing

Tertiary Screening

1 1 x 62/75 1 x MP1000st 1 x 3661-2 2 x MP1000sh 2 x 3073 – 1

2 1 x 62/75 2 x MP800st 2 x 2461-2 2 x MP800sh 2 x 3673 – 1

3 1 x 54/75 1 x MP1000st 1 x 3661-2 2 x MP1000sh 1 x 3073 – 1

4 1 x 62/75 1 x MP1000st 1 x 3661-2 3 x MP800sh 3 x 1861 – 1

5 1 x 62/75 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1

6 1 x 50/65 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1

7 1 x 54/75 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1

8 1 x 54/75 2 x MP800st 2 x 1861-2 4 x HP800sh 4 x 3661 – 2

9 1 x 54/75 2 x MP800st 2 x 2461-2 2 x MP800sh 2 x 3673 – 1

10 1 x 62/75 2 x MP800st 2 x 3061-2 3 x MP800sh 3 x 3673 - 2

There were ten options considered, with some further minor variants, which were not

deemed suitable and thus are not reported. In addition to the plant throughput rate and

product particle size target, the common features of the ten options are:

• Each option consists of three stages of crushing.

• Each option includes secondary and tertiary screening.

• Each option utilises a single gyratory crusher in the primary duty, albeit

considering various crusher sizes in different options.

• All secondary screens used in calculations were double-deck screens.


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• In each option the secondary crushing and screening stage was configured as

open circuit. High level evaluation indicated that closing of the secondary circuit

is impractical in this case. It results in high recirculating load and leads to

uneven distribution of energy utilisation throughout the plant.

• Each option utilised a tertiary circuit in a closed circuit variant, with the tertiary

screen oversize being recirculated to the tertiary crusher feed bin.

• All secondary duty crushers were standard size head.

• All tertiary duty crushers were short head units (to enable tighter settings).

The key differences between the ten options are:

• The primary crusher size was ranged from 50/65 to 62/75.

• The number of secondary crusher units was either one or two.

• MP1000st and MP800st secondary crushers were used.

• Various sizes of double-deck screen sizes with various aperture sizes were

used depending on crusher types.

• Option 8 was set up to approximate the configuration selected by KD

Engineering.

• Three different types of crushers were used in the tertiary duty. These

included: HP800sh, MP800sh and MP1000sh.

• Between 2 and 4 crusher units were used in the tertiary duty.

• Screen sizes were varied and either single or double-deck screens were used.

• Options 1 to 6 used the tertiary circuit feed rate lower than the primary and

secondary, requiring larger intermediate buffer storage capacity.

• Option 10 was further modified by removing the material in the final size product

from the secondary screen undersize. In all other options the secondary screen

undersize was configured to be fed to the tertiary crushing and screening

circuit.

5.1 Circuit Options Discussion

A schematic simplified process flow diagram for the Option 1 is shown in Figure 5-1.

Option 1 utilises a 62/75 gyratory crusher followed by a single unit secondary crusher

and screening stage. In this configuration a MP1000st crusher was selected. The

tertiary crushing and screening stage includes two MP1000sh crushers. The primary

crusher will be fed at a design tonnage of 1 800 t/h. The crusher discharge will be

screened using a double-deck vibrating screen. The screen oversize will then report to

the secondary crusher and the undersize will be transferred to the tertiary crushing and

screening circuit. The tertiary circuit will be fed at a design tonnage of 1 400 t/h. This

indicates that a large intermediate buffer storage capacity would be required between

the secondary and tertiary parts of the plant.


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Figure 5-1 Option 1 Flowsheet

The configuration used in the Option 1 would not facilitate operating of the tertiary

circuit at the same rate as the primary and secondary part of the plant. The two tertiary

crushers will not have sufficient throughput capacity to be able to process 1 800 t/h. At

this tonnage screening would become inefficient and crushers would be overloaded.

The operating philosophy in this case would be to operate the tertiary circuit at a lower

throughput rate but over a longer period of time i.e. using higher overall utilisation of

the tertiary circuit. The configuration used in Option 1 will result in fewer secondary

and tertiary equipment numbers then the subsequent options, potentially leading to

reduced capital expenditure but, at the same time, it will require a relatively large

intermediate buffer storage capacity. At the same time, fewer equipment numbers

would reduce redundancy and cause inability to operate the plant at a reduced

throughput, for example when the secondary crusher is taken off line for maintenance

or any other reason. Additionally, the limited capacity of the tertiary circuit will reduce

the potential for catch up and sprint capability of the plant, but these factors may be

significant aspects of the plant operation given the climatic conditions and nature of

heap leaching operations.


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In Option 2 the single MP1000st secondary crusher was replaced with two MP800st

units. This configuration improves the operability of the secondary circuit and

increases the maximum theoretical capacity of the primary and secondary circuits.

However, with two MP800sh crushers in the tertiary duty the spare capacity of this part

of the circuit is limited above the design 1 400 t/h and the intermediate buffer storage is

required.

Option 3 is a variant of Option 1 with the primary gyratory crusher size reduced to

54/75. There is some capital expenditure benefit resulting from this selection.

However, the reduction in the size of the primary crusher necessitates an increase in

the close side setting to enable processing of the required tonnage throughput. The

effect of this is that the reduction ratio in the primary crusher is decreased implying that

more work will have to be done in the secondary and tertiary crushing stages in order

to achieve the required product particle size distribution.

Option 4 has the same primary and secondary configuration of Option 1. The

difference is that two MP1000sh crushers in the tertiary duty are replaced with three

MP800sh crushers. In this configuration it is possible to operate the whole plant at the

same throughput rate of 1 800 t/h without surge capacity, or one of the tertiary crushers

may be taken off line for maintenance, or other reasons, without the necessity to stop

the whole plant.

Option 5 is a modified Option 4. It contains the same primary and tertiary configuration

as Option 4, but a single MP1000st crusher in the secondary duty is replaced with two

MP800 st crushers facilitating operating of the circuit at reduced tonnage should any of

the secondary crushers need to be taken off line and in this way increasing the overall

plant utilisation. This circuit configuration may be operated with or without the

intermediate buffer storage capacity.

Option 6 has the same configuration as Option 5, but the primary gyratory crusher is

replaced with a smaller unit – 50/65. The reduced primary crusher would be expected

to result in some capital expenditure reduction, but the crusher would be operated

under a relatively high load with only limited spare capacity. Also, the size of maximum

particle that may be fed to the primary crusher would be reduced by 250 mm.

Option 7 has the same secondary and tertiary configuration as Option 6, but the

primary gyratory crusher is increased to 54/75, increasing the robustness of the circuit

and having an increased spare capacity relative to the Option 6.

Option 8 has the secondary and tertiary configuration based on the circuit proposed by

KD Engineering in the feasibility study. The difference is that the instead of two

primary jaw crusher a single 54/75 gyratory primary crusher is used. This option was

based on the concept of ramping up the production throughput in two phases and as

such it does not appear to be the most effective choice when aiming for the production


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target of 10 Mtpa from the start. Multiple (four) smaller tertiary crusher may have some

merit when intermediate buffer storage capacity is used, but when the whole plant is

operated at 1 800 t/h taking one tertiary crusher off line would result in the other three

becoming overloaded. Additionally, the installed power in this circuit is at least 20%

higher than for any of the other options, which were designed for the throughput of

10 Mtpa from the start.

Option 9 is a variation of Option 7, but with one tertiary crusher removed. Removal of

one crusher and screen results in the equipment cost reduction, but in this option

intermediate buffer storage capacity is required, as the tertiary crushing and screening

circuit would become overloaded if operated at the same rate as the primary and

secondary part of the plant. It would be expected that the reduction in cost due to the

elimination of one tertiary crusher and one tertiary screen would be negatively offset by

having to provide a significant intermediate buffer storage capacity in the form of a

stockpile or a large bin.

Figure 5-2 Option 10 Flowsheet


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Option 10 depicted in Figure 5-2 contains the equipment configuration that was

selected as a basis for the trade-off study and the subsequent development of the

capital cost estimate.

Option 10 consists of one primary gyratory crusher (62/75), two secondary double-deck

banana vibrating screens, two secondary MP800st cone crushers, three tertiary

double-deck banana vibrating screens and three tertiary MP800sh cone crushers.

Another feature of this option is that the secondary screen undersize will be routed

directly to the product stream rather than being first conveyed to the tertiary screening

section as is the case in Options 1 to 9. This is aimed to increase the flexibility of the

circuit by reducing the load to the tertiary crushing and screening and to prevent the

potential undesirable generation of fines resulting from rehandling of particles that are

already within the specified product particle size distribution. At present Lydian are

allowing 10 days of downtime per annum for adverse weather conditions during which

no mining operations are planned to occur.

The footprint of the Option 10 plant was reduced by eliminating the crushed ore

stockpile that would be typically used as a buffer storage facility either after the primary

or after the secondary crushing stages. Intermediate storage and buffer capacity is

particularly significant in operations that require a substantial period of operating time

to achieve steady state conditions and which are sensitive to stoppages that may

cause a decreased in efficiency or metal recoveries. A crushing and screening

operation, like the one proposed for the Amulsar project, is capable of achieving steady

state in a short period of time (within minutes). In the proposed plant configuration any

buffer storage requirements would be dealt with at both ends of the circuit – by

management of the mining fleet, ROM stockpile and by providing surge capacity at the

end of the circuit to cater for stoppages of the overland conveyor. The proposed circuit

configuration is expected to provide a robust plant with ample catch up and sprint

capability. Given the nature of heap leaching operations, the location of the project and

the climatic conditions in the area, these factors are expected to be key components in

achieving the targeted plant throughput.

Estimating of operating costs for each of the options considered was not carried out as

part of this study. However, power draws for major equipment considered in the

options comparison (crushers and screens) were estimated to vary by less than

240 kW between the ten options. Using a basis of 6 390 operating hours per annum,

10 Mtpa plant throughput and an assumed power cost of USD 0.05/kWh, the 240 kW

range would translate to a variation in the opex cost between the ten options of less

than 1 cent per tonne of ore processed. It is therefore anticipated that, under normal

operating conditions, none of the options considered would have a significant

advantage, or disadvantage, in terms of operating cost in relation to the other options.


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The following Table 5-2 provides a comparison of crushers power installed and power drawn for Option 8 (based KD Engineering feasibility study) and Option 10 (the selected flowsheet) for the current trade-off study.

Table 5-2 Installed vs Drawn Power - Crusher Summary

Stage

Option 8

(KDE Based Configuration)

Option 10

(Trade-off Study Selection)

Installed (MW) Drawn (MW) Installed (MW) Drawn (MW)

Primary Crusher 0.44 0.29 0.34 0.26

Secondary Crushers 1.20 0.66 1.20 0.62

Tertiary Crushers 2.40 0.65 1.80 0.71

Total 4.04 1.60 3.34 1.60

As discussed in preceding paragraphs, the difference in power drawn between the

options considered was found to be negligible, resulting in minor differences in terms of

expected impact on the plant operating cost. However, there are capital cost savings

to be realised in Option 10 as, in relation to Option 8, the installed crusher power is

17% lower in this flowsheet providing a more efficient configuration.


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6.0 PROCESS PLANT DESCRIPTION

The Crushing Plant Description should be read in conjunction with the Process Flow

Diagrams provided in the Appendix D. An overall plant process flow diagram is shown

in Figure 6-1.

Figure 6-1 Crushing and Screening Plant Process Flow Diagram

Figure 6-2 on the following page illustrates the general layout of the proposed crushing

and screening facility forming part of the overall Amulsar Gold Project.


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Figure 6-2 Crushing and Screening Plant Overall Layout

6.1 Area 2110 Primary Crushing

The Primary Crushing section is shown in the PFD number: 140192-2110-49D1-0001

in the Appendix D. The primary crusher plant is also illustrated in Figure 6-3 and

Figure 6-4.

Figure 6-3 Primary Crusher Plant


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It is planned to mine ore from a number of pits in order to achieve the required mine

production rate. The general process sequence for the Amulsar Gold Project will start

in the mine pits with loading of ROM ore into trucks which will take the ore to the ROM

pad, where it will be tipped into a Primary Crusher Dump Pocket (2110-BN-001).

Tipping will be from both sides of the dump pocket. From the dump pocket, ore will

gravitate into the Primary Gyratory Crusher which will reduce the ROM ore from a

nominal top lump size of 700 mm diameter to a top size of 355 mm and P80 of

approximately 130 mm. Some re-handle on the ROM pad to maintain plant utilisation

is expected.

At full production the total design feed rate will be 1800 t/h. The Primary Crusher has

been sized to process the largest pieces of ROM ore at 700 mm diameter. However,

the design of the selected crusher enables feeding particles of up to 1 260 mm if

required and as may be necessitated by the mining operations.

Coarse ore lumps which block the crusher throat will be broken up by a Rock Breaker

(2110-RB-001) located adjacent to the Primary Crusher Dump Pocket (2110-BN-001).

Ore which has passed through the crusher will enter the Primary Crusher Discharge

Bin from where the ore is withdrawn by a Primary Crusher Low Profile Belt Feeder

(2110-CV-001). The low profile belt feeder will discharge onto the Primary Crusher

Discharge Conveyor (2120-CV-001).

The primary crusher will be fitted with dust collection equipment (2110-PK-001) and the

production tonnage will be monitored by the Primary Crusher Discharge Belt

Weightometer (2110-WE-001).

When the primary crusher is out of service for maintenance, the ore from the pit will be

dumped on the adjacent ROM pad. From here it will be rehandled for feeding into the

Primary Crusher using front end loaders.

At the discharge end of the Primary Crusher Discharge Conveyor, any entrained tramp

metal will be collected by the Tramp Magnet (2110-MG -001). Recovered tramp metal

will be dropped at intervals via the Tramp Magnet Discharge Chute (2110-CH-004) into

a Tramp Magnet Bin (2110-BN-003). Ore from the Primary Crusher Discharge

Conveyor will gravitate via the Primary Discharge Conveyor Head Chute (2110-CH-

001) to the Secondary Screen Feed Conveyor (2120-CV-001) which will be fitted with a

Primary Crusher Discharge Weightometer (2110-WE-001). The Secondary Screen

Feed Conveyor will discharge via the Secondary Screen Feed Conveyor Head Chute

(2120-CH-001) to the secondary screen feed bin.


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An example of a typical primary gyratory crusher installation is shown in

Figure 6-5

Document No: Rev

140192-30RF-I-0001 PC

Figure 6-4 Primary Crusher Plant

An example of a typical primary gyratory crusher installation is shown in

5 Example of a Primary Gyratory Crusher Installation

Date: Page

17/12/12 34 of 59

An example of a typical primary gyratory crusher installation is shown in Figure 6-5.

Example of a Primary Gyratory Crusher Installation


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6.2 Area 2120 Secondary Screening

The Secondary Screening section is shown in the PFD number: 140192-2120-49D1-

0001 provided in the Appendix D and it is also illustrated graphically in Figure 6-6.

Secondary Screen Feed Bins will have two discharge points, each of which will feed

ore to the secondary screening circuit comprising two parallel belt feeders, double deck

screens and product conveyors. Ore withdrawn from Secondary Screening Feed Bins

(2120-BN-201, 202) will be fed via Secondary Feed Bin Discharge Chutes (2120-CH-

101, 201) by Secondary Screen Belt Feeders (2120-FB-101, 201) onto Secondary

Double-Deck Screens (2120-SN-101, 201). Each screen will be fitted with two screen

decks. The upper screen will have 75 mm square apertures while the lower screen will

have 20 mm square apertures.

Secondary screen oversize will gravitate via the Secondary Screen O/S Chutes (2120-

CH-104, 204) to the Secondary Oversize Conveyor (2130-CV-001). The Secondary

Screens product will pass via Secondary Screen Discharge Chutes (2120-CH-103,

203) to the Secondary Screen U/S Conveyor (2160-CV-001).

Dust control will be provided by ductwork on all major transfer points.

The secondary screen O/S conveyor will discharge to Secondary Crusher Feed Bins

(2130-BN-101, 201). The secondary screen U/S conveyor will discharge to the Fine

Ore Bin. The secondary/tertiary screening equipment will be fitted with dust collection

equipment (2140-PK-001) comprising a dry baghouse, fan and associated ductwork.

Figure 6-6 Secondary & Tertiary Screening Plant


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6.3 Area 2130 Secondary Crushing

The Secondary Crushing section is shown in the PFD number: 140192-2130-49D1-

0001.

The Secondary Crushing Feed Bin will have two discharge points, each of which will

feed ore to the secondary crushing circuit comprising two parallel belt feeders, cone

crushers and crushed product conveyors.

Ore withdrawn from Secondary Crusher Feed Bins (2130-BN-101, 201) will be fed via

the Secondary Crushing Feed Bin Discharge Chutes (2130-CH-101, 201) by the

Secondary Crusher Belt Feeders (2130-FB-101, 201) via the Secondary Crusher Feed

Chutes (2130-CH-102, 202) into the Secondary Crushers (2130-CR-101, 201).

Secondary crusher discharge will gravitate via the Secondary Crusher Discharge

Chutes (2130-CH-103,203) to the Secondary Crusher Discharge Conveyor (2140-CV-

001).


The secondary crusher discharge conveyor will discharge to Tertiary Screening Feed

Bins (2140-BN-101,201,301).

An illustration of a typical cone crusher that would be used in the proposed duty is

shown in Figure 6-7.

Figure 6-7 Example of a Cone Crusher


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6.4 Area 2140 Tertiary Screening

The Tertiary Screening section is shown in the PFD number: 140192-2130-49D1-0001.

Tertiary Screening Feed Bins will have three discharge points, each of which will feed

secondary and tertiary crushed product to the tertiary screening circuit comprising three

parallel vibrating feeders, double deck screens and product conveyors. Ore withdrawn

from Tertiary Screening Feed Bins (2140-BN-101,201,301) will be fed via the Tertiary

Feed Bin Discharge Chutes (2140-CH-101,201,301) by the Tertiary Screen Vibrating

Feeders (2140-FV-101,201,301) onto Tertiary Double-Deck Screens (2140-SN-

101,201,301).

Tertiary screen oversize will gravitate via the Tertiary Screen O/S Chutes (2130-CH-

010,011,012) to the Tertiary Screen Oversize Conveyor (2140-CV-001). The Tertiary

Screen product (undersize) will be conveyed to the crushed ore surge been prior to

being transported via the overland conveyor to heap leach stacking. Each screen will

be fitted with two screen decks. The upper screen will have 32 mm square apertures

while the lower screen will have 18 mm square apertures.


Figure 6-8 Example of a Double-Deck Banana Screen


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6.5 Area 2150 Tertiary Crushing

The Tertiary Crushing section is shown in the PFD number: 140192-2150-49D1-0001.

The Tertiary Crushing Feed Bin will have three discharge cones, each of which will

feed ore to a tertiary crushing circuit comprising three belt feeders and three short head

cone crushers.

Ore withdrawn from the Tertiary Crusher Feed Bin (2150-BN-101, 201 & 301) will be

fed via the Tertiary Crushing Feed Bin Discharge Chutes (2150-CH-101, 301) by the

Tertiary Crusher Belt Feeders (2150-FB-101, 201 & 301) via the Tertiary Crusher Feed

Chutes (2150-CH-101, 201 & 301) into the Tertiary Crushers (2150-CR-101, 201 &

301).

Tertiary crusher discharge will gravitate via the Tertiary Crusher Discharge Chutes

(2150-CH-101, 201 & 301) to the Tertiary Crusher Discharge Conveyor (2140-CV-001).


The Tertiary Crusher Discharge Conveyor will discharge to the Tertiary Screening Feed

Bin (2140-BN-101,201,301).

Figure 6-9 Secondary & Tertiary Crushing Plant


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6.6 Area 2160 Product Loadout

The Product Loadout section is shown in the PFD number: 140192-2160-49D1-0001.

The Crushed Ore Surge Bin will be located adjacent to the Tertiary Screening Building,

and will be of an equivalent height. The crushed ore surge bin will have interconnected

walkways to allow operator access and for heating.

6.7 Area 2900 Plant Heating

The Plant Heating section is shown in PFDs number: 140192-2960-49D1-0001 & 0002

provided in the Appendix D.

The heating system design is based on a hot water supply. The hot water will be

supplied using a boiler package 2960-PK-001 and circulated to the plant building. Heat

exchanger and fan propelled heaters are proposed for this duty. Illustrations of a

typical boiler and heat-exchanger type heater that could be used in this duty are shown

in Figure 6-10 and Figure 6-11.

Figure 6-10 Example of a Typical Industrial Hot Water Boiler


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Figure 6-11 Example of a Typical Industrial Heater

6.8 Fuel Supply

Fuel, gas and lubricants will be dispensed as an “over-the-fence” supply contract by a

fuel supply company. These are outside of the scope of this study. An installation of

appropriately sized facility to match the Project demands will be required.

6.9 Personnel Accommodation and Transport

No allowance has been made in the crushing plant estimate for operating personnel

accommodation and transport.

6.10 Process Buildings and Facilities

Process-related buildings to be constructed on the plant site will include:

• Central control room housing the PLCs and SCADA system; including ablutions

for operational staff.

• Boiler house.

• MCCs and PLC rooms (equipped with filtered, forced air ventilation and fire

suppression system).


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7.0 CAPITAL COST ESTIMATE

A capital cost estimate (CAPEX) has been undertaken for the proposed revised layout.

The relevant estimating documentation, showing detailed breakdown of each area, is

provided in the Appendix B. The capital cost estimate summary for the revised

crushing and screening plant layout is summarised in Table 7-1. The crushing and

screening component contains an adjustment of USD 6,794,916 to allow for the

inclusion of the fine ore bin and lime silo and which is based on the KD Engineering

estimate as agreed in discussions between Lydian International and SNC-Lavalin.

Table 7-1 Capital Cost Estimate Summary

Area Area Total Cost (USD) % of Cost

Crushing & Screening 71,442,822 50.4

Services 12,765,293 9.0

Sub-Total Direct Costs 84,208,115 59.4

Plant Wide Earthworks 10,861,910 7.7

EPCM 14,500,0000 10.2

Growth 8,800,000 6.2

Contingency 19,500,000 13.8

Spares 1,410,000 1.0

Vendor Reps 1,500,000 1.05

First Fill 1,000,000 0.7

Sub-Total Indirect Costs 57,571,910 40.6

Grand Total 141,780,025 100.0

The level of accuracy obtained in this study is of the magnitude of ±15%, a summary of

the estimate build-up and parameters associated with the capital cost estimate are

provided in the Appendix B.


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7.1 Equipment

• Mechanical equipment: quotations sourced from the market via vendors with a track

record in the industry, sole sourcing from some vendors was adopted to reduce

overall study timeline, detailed specification driven multiple vendor bids may be

undertaken in the next study phase to maximize cost competitiveness.

• Electrical equipment: quotations sourced from the market via vendors with a track

record in the industry.

• Instrumentation and Controls: conceptual P&ID’s produced, costs factored utilising

in-house data.

7.1.1 Bulk Earthworks

• Terrain 3D model developed from SD contours provided by Lydian International

Ltd.

• Cut and fill quantity MTO developed from the earthworks 3D model.

7.1.2 Plant Buildings

• Control Room Building cost estimated by cost/m2 basis.

7.2 Structural - Concrete

Concrete foundation MTO’s are generated on a plant area basis:

• Preliminary design of main concrete footings, slabs and rafts. Concrete outline

models generated.

• Concrete is categorized by specific footing types and concrete volumes extracted

from the 3D model, rebar rates applied from database for specific footing types,

slab types etc.

7.3 Structural – Steelwork

Steelwork MTO’s are generated on a plant area basis:

• Preliminary structural design of main members, steelwork models generated.

• Steelwork tonnages extracted on area basis from the 3D model and grouped into

categories, light, medium, heavy and extra heavy members, grid mesh, handrail,

stairs and ladders.

• Preliminary design of fabricated steelwork, bins etc, platework and stiffeners by

manual MTO produced.


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7.4 Mechanical

• Mechanical equipment – refer to section 7.1.

• Mechanical platework items are assigned a unique equipment number e.g. chutes,

distribution boxes etc.

• Ductwork for dust extraction system and baghouses via manual MTO.

• Manual MTO’s are generated on a plant area basis.

7.5 Piping

• Piping for hot water system via manual MTO.

• Manual Valves: manual quantity take-off based on the conceptual P&ID’s.

7.6 Electrical

• Electrical Equipment, refer to section 7.1.

• LV distribution, cables schedules etc, based on overall layout and factored via

database.

• Medium Voltage (6.6kV) VSDs are used as soft starters.

• Cable trays, linear metres, manual take-off.

7.7 Instrumentation

Instrumentation interface and PCS I/O requirements was factored from similar project

via in-house database.

7.8 Miscellaneous Items

Manual MTO’s were produced to accommodate items where modelling has not been

undertaken.

7.9 Indirect Costs

Indirect costs include:

• Mobilization and demobilization costs of the construction workforce.

• Growth Allowance: quantities which are known to be required, but lacking in detail

have a growth allowance applied.

7.10 EPCM Costs

EPCM costs include:


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• Engineering – design, bid evaluation, shop detailing and spooling.

• Procurement - tenders, buying, expediting, inspection, warehousing.

• Project Management, scheduling, project controls, commercial management and

contract management.

• Construction Management, stores management and equipment hire management.

7.11 Estimate Accuracy

Estimate accuracy is in-line with estimating norms, for a Class 3 to 4 study estimate

with a magnitude of plus 15% minus 15%.

7.12 Contingency

Allowance for the unknown, which is included as an indirect cost.

7.13 Battery Limits

The battery limits for the capital cost estimate encompass:

• Retaining wall at the interface with the ROM (run of mine) Primary Crusher

Feed Bin.

• Shuttle feed conveyor chute discharge interface to the crushed fine ore bin.

However, it was agreed that KDE design and estimate will be used for the

purpose of the fine ore bin and lime silo costing to facilitate a direct comparison

with the SNC-Lavalin estimate.

• Incoming terminals of the HV distribution board 6100-HV-001 shown on

SLD140192-2000-47D1-0001 and located at the crushing and screening plant.

• All automated control functions will be performed on the plant PCS provided by

others. The battery limit for instrumentation is the I/O rack and a marshalling

panel located in the crushing and screening plant.

7.14 Estimate Exclusions

The following items are not incorporated in the process plant capital cost estimate.

The following items are excluded from this estimate:

• ROM pad and retaining wall.

• Roads and drainage.

• Crushed fine ore bins, support steelwork and concrete foundations are based

on the KD Engineering design and estimate.


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• Crushed fine ore bin building.

• Main Plant PCS.

• Utility pipework, inclusive of:

o Fire water system

o Potable water system

o Plant and instrument air system

o Process water system

o Raw water system

o Internal drainage pipework within the buildings and collection/distribution

system

7.14.1 Commissioning

No allowance has been made for a commissioning team or support from the

construction team with respect to commissioning and should be included as Owners

Cost.


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8.0 ESTIMATE COMPARISON

A comparison of inclusions and exclusions between the study estimate and the

feasibility study estimate prepared by KD Engineering are highlighted in Table 8-1.

Table 8-1 Estimate Inclusions Comparison

SNC-Lavalin Trade-off Study Estimate KD Engineering Estimate

Buildings heated for cold climatic

conditions.

Not stated in the information pack

provided.

Boiler building, boiler and heat exchanger

units and piping system allowed for in the

estimate.


provided.

Building, roof and side sheeting

composite sandwich construction for cold

climatic conditions.


provided.

Conveyors covered and walkways

allowed on enclosed conveyor gantries

allowing internal access to buildings.


provided.

Concrete raft concept design for all

buildings for seismic design

considerations.


provided.

Building purlins and girts designed for

snow load/additional loadings with

respect to the selection of composite

sheeting.


provided.

HV Transformers, concrete slab and blast

wall, foundation and bund wall

incorporated.


provided.

The following Table 8-2 provides a comparison of the original KDE Engineering

estimate, SNC-Lavalin estimate and the KDE estimate adjusted using various factors

and subsequently explained.


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Table 8-2 Capital Cost Estimate Comparison

Area KDE Original

Estimate (USD) SNC-Lavalin

Estimate (USD) Adjusted KDE

Estimate (USD)

Direct Costs

Primary Crushing &

Screening 12,994,231 12,831,201 12,994,231

Secondary Crushing &

Screening 23,017,856 19,647,155 23,017,856

Tertiary Crushing &

Screening 27,426,687 30,219,359 27,426,687

Product Loadout 8,856,745 1,950,191 8,856,745

Buildings Included above 12,765,293 Included above

Sub-Total Directs 72,295,519 77,413,199 72,295,519

Indirect Costs

Earthworks 11,765,000 10,861,910 11,765,000

EPCM 19,277,222 14,500,000 19,277,222

Owners Costs 6,000,000 Not itemised 6,000,000

Spare Parts 4,676,700 1,410,000 4,676,700

First Fill 1,185,900 1,000,000 1,185,900

Vendor Reps Not itemised 1,500,000 Not itemised

Mobile Equipment 1,855,000 Not itemised 1,855,000

Growth Allowance Not itemised 8,800,000 Not itemised

Contingency 19,069,206 19,500,000 19,069,206

Sub-Total Indirects 52,064,028 46,710,000 52,064,028

Total Cost 136,124,547 134,985,109 136,124,547

Adjustments

Concrete - - 10,000,000

Electrical & Instr. - - 8,500,000

Escalation - - 1,019,000

Product Loadout - 6,794,916 -

Adjusted Total Cost 136,124,547 141,780,025 155,643,529


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The column labelled “KDE Estimate” provides an extract from the original estimate

covering the crushing and screening plant. The column “SNC-Lavalin Estimate”

provides a summary of the crushing and screening cost as currently developed by

SNC-Lavalin. The adjusted total cost includes the product loadout section adjustment.

This adjustment was introduced to ensure that the two estimates are compared on the

same basis and using the same battery limits. Following discussions with Lydian it was

agreed that the cost estimate of fine ore bins and lime storage silo will be added to the

SNC-Lavalin estimate for this purpose.

SNC-Lavalin conducted a high level review of the KD Engineering estimate and

subsequently proposed a number of adjustments, which in SNC-Lavalin’s opinion

would result in a more realistic estimate. This is summarised in the column labelled

“Adjusted KDE Estimate”.

The first major consideration is the cost of concrete. KDE used a figure of USD 150

per cubic metre, which is considered to be significantly understated. Additionally, in an

email dated 19/10/2012 and entitled “KDE Concrete Costs”, Lydian International

provided SNC-Lavalin with information indicating that KD Engineering stated that the

original cost of concrete was underestimated by approximately USD 10M – thus the

concrete adjustment value shown in Table 8-2. For the purposes of this study it was

believed to be more appropriate to use KDE’s own adjustment since it was made

available.

In the capital cost estimate SNC-Lavalin applied factors to the mechanical equipment

cost to generate a series of costs for electrical and instrumentation associated with the

process plant areas. These factors are well understood and defined for similar plants.

However, the electrical and instrumentation costs in the KD Engineering estimate

indicate a much lower cost factor, which equates to the order of 6% of the mechanical

equipment cost. The differential between the SNC-Lavalin and KD Engineering

estimates is in the order of USD 8.5M. For comparison purposes SNC-Lavalin propose

that USD 8.5M be included in the KD Engineering estimate to make up for this

difference.

To further facilitate a direct comparison, SNC-Lavalin based the labour rates on the KD

Engineering rates, which include a productivity factor of 2.0. It is SNC-Lavalin’s opinion

that a more suitable productivity factor for the region where the project is to be

undertaken should be 3. This does not affect the comparison in this study and the

aspect can be addressed in the next phase of the project.


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The KD Engineering estimate is approximately 6 to 9 months old and SNC-Lavalin

therefore suggest that an escalation factor of 2.5% should be added to the KD

Engineering estimate to bring it in line with SNC-Lavalin’s estimate.

amulsar gold project - lydian · lydian international ltd. commissioned snc-lavalin to conduct a...

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