World Mining – Future mass mining options under consideration30 September 2014

WealthUnearthed

• Ideas presented are a result of the author’s direct involvement (in conjunction with industry technical leaders) in major international and collaborative research projects on mass mining methods and blasting: – International Caving Study (ICS)– The Mass Mining Technology (MMT)– Supercaves (2011 – 2014)– Hybrid Stress Blasting Model (HSBM)– The Next Generation Cave Mining (Phase 1 (2014)– Ultra-Deep open pit mining (conceptual study and workshops )

Illustrations and figures used have been sourced from ICS, MMT, Supercaves and The Next Generation Cave mining member companies and are therefore

acknowledged

DISCLAIMER

An observation

The mining industry is now moving rapidly into a new and potentially much higher risk investment territory…..……“easy” and “near surface” orebodies are being consumed

NOTE:

During this presentation, we need to also think of how “the new and potentially much higher risk investment territory” is likely going to impact on the drilling and blasting (explosives) industry”. Also what

are the opportunities?.

Depletion of near surface deposits and increasing discoveries of Deeper

Deposits generally with Lower average Grades but with very large mining

footprints (ranging from approx. 5 ha to just over 200 ha).

Increasing demand for production from Underground Mass Mining Sources

to supplement Surface Mass Mining Sources

Deposits in Stress and Temperatures (Geotechnical/Geothermal/?) much

higher than previous and current experience

Environmental constraints (License to Operate) and associated legislations

Stricter demands for better Energy and Water management or utilisation

Developing new mining projects under Capital Constraint

The mass mining industry must change

The Mining Industry “Drivers for Change”

MASS MINING

� Mass mining may be carried out either by:

− large open pits;

− bulk underground mining methods:

○ block and panel caving (BC/PC)

○ sublevel caving (SLC)

○ sublevel open stoping (SLOS)

○ Generally non-selective with production

rates of greater than 10,000 tpd

BUT: Can equally have economic, technical, safety and environmental risks that need to be properly managed.

To maintain profitability whilst minimising risk requires on-going R&D to address existing and new KNOWN –UNKNOWNS of cave mining.

Cave mining increasingly a method of choice to extract low grade massive ores profitably

Increased production from underground cave mining

(e.g. Copper, Molybdenum and Gold)

Increased use of automation (mainly trials and prototypes)

Intelligent mining (ITC)

Remote Centre Operations

Stricter adherence to License to Operate

MINING TRENDS: Since 2009

INCREASED UNDERGROUND

PRODUCTION IN THE NEXT

30 YEARS

(200 KTPD TO 500 KTPD)

INCREASED UNDERGROUND

PRODUCTION IN THE NEXT

30 YEARS

(200 KTPD TO 500 KTPD)

CODELCO CHILE

Automation and Remote Centre Operations

Future Mass Mining Options

Ultra deep pits

Transition

Deep and large footprint cave mines

In-situ mineral extraction

4.5 km

2.7 km

850 m deepFinal depth > 1km

Undercut levels approx.2 km below surface

Aim is to drill into the mineralised region at depth,

precondition ore and leach-out metal from

mineralized zone (recovering ~1-2% of ore mass and

leaving ~99% of gangue in place)

Next Generation Surface Mass Mining

Applying large scale open pit mining to depths equal and/or greater than 1000m and approaching 1800m as well as the ability to also mine up to a Gigatonne-per-year mining (ore and waste) from a single or multiple or linked group of open pit operations (BHP Billiton 2012)

Challenges and Opportunities

• Mine design and planning for mega-pits

• Drilling and blasting options (optimised fragmentation and liberation)

• Increased productivity via mega blasts

• Continuous and high productivity materials management system for the Giga-tonne per-annum open pit mining

• Waste rock management

• Selective mining “Grade engineering”

• Orebody geology in its broadest sense

If 5% of your material causes 50% of your downtime, the whole project is at risk. Courtesy of SKM

Ultra Deep Open pit mining options

Various Shovel – Truck Systems

Truckles operations

In-pit crushing and conveying systems (IPCC): fixed, semi-mobile, fully mobile

Combination of surface and underground material handling systems

Near to vertical final pit walls (slopes)

Steep conveyor systems

Mega-blasts

What constitutes “ULTRA-Deep Pits” and what percentage of the industry is likely

to mine such pits (i.e. Pits with depths greater than e.g. 1200m to 1800m) in the

next 10 to 15 years ?

How deep can current pits be mined effectively, safely and economically using

current practice and technology ?

At what point should transition to cave mining methods be considered i.e.

geotechnical, economic, environmental, technological, productivity ?

What unique issues are likely to be faced by the Ultra-deep pits ?

What are requirements of the future large scale and deep open pits also looking at

technical and material handling issues

What are the logistical issues likely to be faced (human, automation, interaction) ?

Key questions

HIGH CAPACITY & ULTRA DEEP OPEN PIT MINING

12

Main points to consider:

Slope angles and Mine Design

1. Geotechnical model.2. Stress distribution.3. Maximum wall heights.4. State of the art in control of slopes.5. Large push-backs and connectivity.

Material Handling

• Mine design as material handling system.• Reducing distance haulage.• Autonomous trucks• Trucks alone in the pit.• High angle straps.• Material pass Systems, tunnels and straps.• Crushers in the pit and / or underground.• Elevators.• Shovel / conveyor belt

Others Considerations

1. Suppliers are looking for partners to develop unproven technology.

2. Underground infrastructure development. (Eg caves for crushing room, etc.)

Types of deposits

1. Mass and low grade (ratio W / O low).2. Plant: Technology to process low grade

ores.

Implementation

1. Methodology tunneling (TBM, conventional)2. Prestripping

Anglo-American Copper

The next generation of cave mining

Gravity cave mining systems: grizzly and slusher layouts

Focus areas:

Caving of massive, low strength and usually low-grade ore bodies which produced fine fragmentation

Gravity and “Chimney” caving

Manual operations

Stability of small extraction layouts

Support of extraction levels

Rock mechanics

Dilution

1st GENERATION CAVE MININGPre- 1980

Example of focus areas:

Cave mining in strong ore rocks (primary rock) and at moderate depths

Alternation mining layouts (panel caving)

Mechanisation

New ground support concepts

Production efficiency utilising batch systems and current extraction level layouts e.g. Teniente and Herringbone

Rock mechanics and Numerical modelling

Increased safety

2nd Generation Cave Mining1980 to Current

Orebody knowledge (plus variability and uncertainties)

Rapid and safe access to deep orebodies (Rock cutting vs. drilling and blasting)

Rapid and Safe cave establishment (Rock cutting, long-rounds and rapid short round)

Continuous and automated production systems

New cave mining layouts for automated and continuous production)

Significantly reduced mining costs (CAPEX and OPEX)

Minimum environmental impacts (licence to operate)

Human capital

New generation cave mining operators, technicians, and engineers and management processes

Better integration between mining and processing (next generation Mine to Mill)

Risk and Safety

Focus areas (The Next Generation Cave Mining)

Vision of the Next Generation Cave Mining

Feasibility of machine mining

Mechanical Undercutting System

Drill and Blasting Undercutting

Chitombo, 2010

Peng, 1983Work area ahead of cutting front

Work area behind cutting front

CODELCO’SSupercaves

Comparisons

(approximations)

Current caving operations

Footprint ± 200m X 200mBlock heights ≤ 500mTonnages: 10,000 – 40,000 tpdUndercut level = < 1.5 km

± 500 drawpoints

SupercavesFootprint=± 2km x 2kmBlock heights ≥ 500m approaching 1000mTonnages 70,000 tpd approaching 160,000 tpd (single panel)Undercut levels = >1500m approaching 2000m1000 – 2000 drawpoints

20

1500m

To form an international mining industry collaboration (consortium) to fund, support and therefore accelerate the development of critical and high impact innovations as well as the underpinning knowledge (supporting research) needed to ultimately achieve the desired End-State (Vision 2018/2025)

To also collaboratively address and develop solutions to manage a number of the foreseen technical, economic and environmental challenges that the cave mining industry is likely to face henceforth and worldwide (known-unknowns).

The Goal (an industry perspective)

Benefits of electronic detonator blasting demonstrated

Fragmentation

Throw

Vibration control

Bulk delivery systems standard practice

Mine to Mill philosophy attempted but with mixed results

Little change in the bulk explosive product energy range

Little work tailoring blasting to different geology's. Tendency one size fits all at sites.

Much improved drilling technology (More accurate drilling)

MWD (not readily used for D&B design and optimisation)

Advancements in computer blast modelling (e.g. HSBM)

The drilling and explosives industry:The last 15 to 20 years

Geomechanical code

Detonation codesIdeal and non-

ideal

VixenBlo-Up

Modelling EngineDetonation

Fracturing

Fragmentation

Displacement

Near-field Damage

Rock and fragment Conditioning

Back of

detonation

driving zone

(sonic surface)

Shock front

End of

reaction

zone

Detonation modelling The rock breakage engine

The Hybrid Stress Blasting Model (HSBM)

Some OPPORTUNITIES FOR EXPLOSIVES COMPANIES

Rapid and safe development (long round drilling and blasting or short rounds)

Preconditioning to enhance caving (confined and/or unconfined blasting)

Sublevel caving blasting to improve fragmentation and recoveries

Ultra-deep pits – blasting for increased productivity

More effective wall control practices for the ultra-deep pits

Leaching- Blasting for increased leaching recoveries (in-situ and heap)

Fragmentation for alternative mills (e.g. HPGR)

Fragmentation for optimal ore/waste sorting or “Grade Engineering”

Truckles mining – controlled fragmentation for conveyors or IPCC

Wireless booster for increased blasting flexibility

Blast monitoring and sensors

PRECONDITIONING BY CONFINED BLASTING

Hole diameter 165mm

Hole length 150m

Charge length 130m

Charge weight ~3,285 Kg

Density Emulsion 1.18 g/cm3

VOD Emulsion >5,500 m/s

Stemming high strength plug

20m

Cure time stemming plug 72hr (minimum)

UCS stemming plug 50MPa (minimum)

Location initiation pointsEvery 8m along of explosive column

Initiation time Every point in the column are started simultaneously

PC1-S1

Lift 1

UCL level

EXT level

Hydrofracturing Level (5050mRL)

Finally

The Next Generation Mass Mining

….novel initiatives are being considered for the next generation of both underground and surface mass mining systems.

This in order to access and established mass mining methods much faster and safer than current, significantly reduce mining costs (CAPEX and OPEX), substantially increase productivity (continuous) while being cognisant of license to operate issues.

NEXT GENERATION MINERAL EXTRACTION: a more integrated mineral extraction system.

World Mining – Future mass mining options under consideration28 September 2014

Thank You