Development & Construction Update of the Grasberg Block Cave Mine€¦ · Development &...

Development & Construction Update of the Grasberg Block Cave

MineMay 2016

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• Describe Designs, Development Status and Construction Status for the Grasberg Block Cave Mine (GBC)

• Overview of Grasberg Mining District• Summary Overview of Grasberg Block Cave Mine

• Caving Plan Overview

• Mine Design and Facilities Overview

• Backbone Systems

• Development and Construction Status

• Conclusions/Questions

Contents

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Grasberg (Ertsberg) District Location

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District Orebody & Access Overview

GBC Terminal:

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Grasberg Block Cave MineKey Facts

AB Adits 2500 m

Vent & Conveyor Drifts

Mill 3000 m

Extraction Level: 2830 m

1 kilometer

962 Mt @ 1.03% Cu, 0.78 g/t Au Cutoff grade ca. 0.60% EqCu 18 bn lbs copper; 16 mm ozs gold

(payable)

2,416 drawpoints El Teniente (Diagonal) Layout 700,000 m2 footprint 30m x 20m drawbells

Mining Rate: 160 ktpd Primary Mine Access via 6-km AB Adits

Gravity Drainage

Service Shaft for men & materials Rail Haulage to a 3-Crusher Complex

Incline conveyors to surface

Intake/Exhaust Adits

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• 1995: Initial GBC reserve established• 2003: Prefeasibility Study completed• 2004: Initiate AB Adit Access Development• 2006: Initiate GVD (Vent Declines); Upper Access Development

• Initiate Feasibility Study• 2008: Feasibility Study Completed• 2011: Initiate Shaft-Sinking (2016 Commissioning)• 2012: Commission Main Fan #1• 2015: Commence fixed facility construction• 2016: Commence extraction level construction• 2017: Commission Crushing & Conveying System; Commission Rail System• Early 2018: Initiate Undercutting & Drawpoint Production• 2024: Full Production

Project History and Plan

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Summary of GBC Mine Layout

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GBC Mine General Layout

GRS Final Pit

GBC

CrushersPumpsInterlevel Ramp

AB Adit

3000 Amole Adits

Hoistroom

BatchPlant

ServiceShaft

2535 GBC Terminal

Interlevel Ramp2850 Undercut Level

2830 Extraction Level2810 Vent/Service Level2760 Haulage Level

2710 Drainage Level

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GBC Mine General Arrangement

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Caving

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Current Undercutting Sequence

PB1N

PB1S

PB1E

PB2N

PB2S

PB3C

PB3N

PB3S

PB4C

PB4N

PB4S

PB5N

200 m

N

1

2

3

1

2

3

4

5

6

7

8

9

10

PB2C

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Advanced Undercutting System Average column height >450m Caving Initiated in year 2018

- Caving @ hydraulic radius = 33 8 drawbells per month maximum opening rate

- 4 per month in one cave front (2,400 m2)- 6 per month when only one cave front available

0.28m (11”) per day maximum draw rates Initiate undercutting in two production blocks

- “Crinkle-cut” style undercutting- Accelerate production ramp-up- Maximize early metal production

GBC Feasibility - Caving

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Production Forecast

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Infrastructure

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GBC Service Shaft

Primary mode of transportation for men & materials

- 353m long, 8.5m diameter concrete-lined

- Hoist: 4.88m diameter double-drum modified Blair

- 38.4 tonne payload- Cage: double deck, 300 miner

capacity- Not for ore or waste delivery- Commissioning 2016

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GBC Service Shaft

• Working Levels• Hoistroom/Shaft Collar – 2875m El.• Undercut/Batch Plant – 2850m El.• Extraction Level – 2830m El.• Rail Haulage Level – 2760m El.• AB Terminal – 2535m El.

• Major Materials Desinations• Undercut (Batchplant), Extraction

• Most Personnel to:• Extraction Level, Haulage Level

• All Men/Materials delivered via AB Terminal

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GBC Service Shaft

Galloway on the AB Terminal Level

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GBC Service Shaft: Hoistroom

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GBC Fixed Facilities

Underground Facilities:

Maintenance and Repair Shops for Rubber Tire Equip

Rail Shop

Warehouses and Offices

3 Fuel bays

Bus Terminals and Light Vehicle Parking

3 Lunchrooms

3 Mosques and 3 Chapels

1 Wastewater Treatment Facility

AB Terminal 2535 m

Service Shaft

Extraction Lvl 2830 m

Haulage Lvl 2760 m

200 meters

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GBC Extraction Level

200 meters

Rubber Tire Shop

Material Handling Area

Mine Offices

Fuel and Lube Station

Lunchroom & Ancillary Facilities

Mine Warehouse

Shop Warehouse

Construction Laydown Area

Shop Lunchroom

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250 m3/day concrete / shotcrete Dual streams Cement silos with 2-day supply Direct-dump aggregate and sand bins Commissioned 2014

Underground Batch Plant

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Manage projected inflows to the cave from surface & groundwater sources Provide process water for the concentrator 1,260 L/sec capacity with standby of 315 L/s Dedicated Drainage Level: fail safe overflow system via AB tunnels Lower and Upper Pumping Stations ~150m head each Excavation of stations complete in 2016; commissioning in 2017

GBC Pumping System

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GBC Pumping System: Lower Pump Station

GIW 10x 600 hp centrifugal slurry pumps

Drainage Level sumpsAccumulators

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Total Flow = 6.6 million cfm (3,100 m3/s) @ Full Production (2024)- 4 primary intake drifts & 4 primary exhaust drifts (6.8 mW x 9.0mH)- Vent on Demand Systems required

Four x 5,000 kW Howden Mixed Flow Main Fans- 4.05m diameter; 5,000 kW; 710 rpm; 775 m3/s

Fan #1 Commissioned 2012; Fan #2 commissioned 2014; Fan #3 2017

Ventilation

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Rail Haulage: Ore Delivery

Automated Rail System- 1435 mm (standard) gauge

- Overhead Catenary System on main lines

- 40t Schalke electric locomotives (11-12 trains plus one spare)- 20 x 20m3 NMT bottom-dump cars

- 120 loading chutes in full layout

- NMT Unloading Station x 3 delivers ore to 1400-tonne bins / crusher

- Communication-Based Train Controls System: Midroc / Bombardier

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Ore Flow Schematic

Primary Crushing Plants (3)- 1,000 kW 63x89 Gyratory

Crushers (Krupp)

- 1,400–tonne coarse ore bin

- Apron feeder – above crusher

- Metal detectors & magnets

- Discharge conveyor

- Dual conveyor systems

Construction in progress - Commissioning in 2017

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GBC Oreflow Construction April 2016

Apron Feeder

Conveyor601 Tail

O/H Crane Crusher

Eccentric

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Detailed Engineering Ongoing- GBC Ventilation on Demand (VOD) - Ongoing Geotechnical Studies & Caving Design Optimisation- GBC Rail and Ancillary Support Facilities

Construction in Progress to be Completed by end-2017- GBC Service Shaft- GBC Rail System- GBC Fan #3- GBC Ore Flow- GBC Pumping System- GBC Fixed Facilities- GBC Extraction Level infrastructure – lintels, rock-breakers/grizzly's, ore passes and roadways

Current EPCM Activities

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2016 Q2 Schedule – Development to start of Production –Jan 2018

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Thank You