Palabora Mining Company Limited

Palabora Block Cave Mine – a world class benchmark design

Dawid Pretorius, General

Manager Mining, Palabora

Mining Company, South Africa

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Background

Palabora Ore body forms part of the

Palabora Igneous complex formed

by a series of volcanic eruptions.

The Ore Body contains a unique

variety of minerals - copper,

Phosphates, magnetite, uranium,

zirconium, nickel, gold, silver,

platinum, and palladium.

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Background cont.

1965: Commissioning of Palabora Open pit Mine

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Background cont.

1996: Faced with decision to close in 2002 or to go underground.

Rio Tinto decided to start the block cave mine.

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Why Block Cave Mining?U/G mining method

• Suitable for massive orebodies which have a large, regular “footprint” and either dip steeply or are of a large vertical extent.

• By undercutting an area equivalent to the HR, caving is initiated.

• Two major drivers of the caving process are:

• Gravity

• Stresses

• Low OPEX but HIGH CAPEX

Extraction

Level

Draw Bell

Undercut

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Block Cave Mining

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Technical Challenges

•Greatest column height in the world

•Hardest rock for a block cave

•Coarsest fragmentation for a block cave

•Lowest grade underground copper mine in the world @ 0.7% Cu

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Equipment

•17 LHD (Load Haul and Dump) with 2 OEM’s – Caterpillar and Sandvik

•4 Mobile Rock breakers

•5 Water Canons

•Ancillary vehicles

•4 Medium Reach Rigs

•Production Shaft: 2 Cope Winders with 4*32 Ton skips

•Service Shaft: 30 Ton Cage and a Mary Anne

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Technology

PDS (Pedestrian Detection System)

•Dispatch (MMSA)- Fleet and Information Management System

•Gemcom Software (PCBC & CMS)

•Rebop and Arena (Simulation)

•SCADA for Fixed Plant enabling Conditional Monitoring

•Planning (Prima Vera and SAP)

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Management Principles

•Theory of Constraints •Rock Factory – managing value chain

•Planning based on bottleneck requirements

•Planning approach

•Do not skip any maintenance

•Draw Control

•Visible felt Leadership (Safety)

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Achievements

•Safety – One of the Safest underground mines in South Africa AIFR = 0.42

•85% Planned vs. 15% unplanned maintenance on all fixed and mobile plant

•Production: 34,000 tons vs. 30,000 design capacity – Highest volume single shaft in the world

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Achievements

•Best Day 42,998 tons May 2005

•Best Week 37,247 tons Week 22 2008

•Best Month 35,993 tons August 2008

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Future Rio Tinto Block Caves

0.1

1

10

100

0 5 10 15 20 25 30 35 40Contained Equ iv. Copper mineralisation - Mt

Cop

per E

quiv

. Gra

de -

% C

u

Oyu Tolgoi

Pebble

Resolut ion

La Granja

Note: bubble siz e reflects total annual capacity

CompetitorsRT Projec ts

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Where to from here?

•Low grade ore bodies

•Extension for open pit mines

•Mine of the future – remote and autonomous operation possibilities

•21st Century mining is here to stay

Mine-Tech International Conference and Expo, 2-4 November 2009, Johannesburg, South Africa

Questions?

Thank You