3rd Africa Iron Ore Conference 2013 Cape Town, South Africa

OPTIMISING AUSTRALIAN MAGNETITE CIRCUIT DESIGN USING ISAMILL™ TECHNOLOGY

Acknowledge : Barns, Twomey, Walstra

Presented : H de Waal

Disclaimer

This presentation and its contents are confidential and may not be reproduced, redistributed or passed on, directly or indirectly, to any other person or published, in whole or in part, for any purpose without the written consent of Xstrata plc (“Xstrata”). This presentation does not constitute or form part of any offer or invitation to sell or issue, or any solicitation of any offer to purchase or subscribe for any securities, or a proposal to make a takeover bid in any jurisdiction. Neither this document nor the fact of its distribution nor the making of the presentation constitutes a recommendation regarding any securities. This presentation is being provided to you for information purposes only. Certain statements, beliefs and opinions contained in this presentation, particularly those regarding the possible or assumed future financial or other performance of Xstrata, industry growth or other trend projections are or may be forward looking statements. Forward-looking statements can be identified by the use of forward-looking terminology, including the terms “believes”, “estimates”, “anticipates”, “expects”, “intends”, “plans”, “goal”, “target”, “aim”, “may”, “will”, “would”, “could” or “should” or, in each case, their negative or other variations or comparable terminology. These forward-looking statements include all matters that are not historical facts. By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future and may be beyond Xstrata’s ability to control or predict. Forward-looking statements are not guarantees of future performance. No representation is made that any of these statements or forecasts will come to pass or that any forecast result will be achieved. Neither Xstrata, nor any of its associates or directors, officers or advisers, provides any representation, assurance or guarantee that the occurrence of the events expressed or implied in any forward-looking statements in this presentation will actually occur. You are cautioned not to place undue reliance on these forward-looking statements. Other than in accordance with its legal or regulatory obligations (including under the UK Listing Rules and the Disclosure and Transparency Rules of the Financial Services Authority), Xstrata is not under any obligation and Xstrata expressly disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. This presentation may contain references to “cost curves”. A cost curve is a graphic representation in which the total production volume of a given commodity across the relevant industry is arranged on the basis of average unit costs of production from lowest to highest to permit comparisons of the relative cost positions of particular production sites, individual producers or groups of producers across the world or within a given country or region. Generally, a producer’s position on a cost curve is described in terms of the particular percentile or quartile in which the production of a given plant or producer or group of producers appears. To construct cost curves, industry analysts compile information from a variety of sources, including reports made available by producers, site visits, personal contacts and trade publications. Although producers may participate to some extent in the process through which cost curves are constructed, they are typically unwilling to validate cost analyses directly because of commercial sensitivities. Inevitably, assumptions must be made by the analyst with respect to data that such analyst is unable to obtain and judgment must be brought to bear in the case of virtually all data, however obtained. Moreover, all cost curves embody a number of significant assumptions with respect to exchange rates and other variables. In summary, the manner in which cost curves are constructed means that they have a number of significant inherent limitations. Notwithstanding their shortcomings, independently produced cost curves are widely used in the industries in which Xstrata operate. No statement in this presentation is intended as a profit forecast or a profit estimate and no statement in this presentation should be interpreted to mean that earnings per Xstrata share for the current or future financial years would necessarily match or exceed the historical published earnings per Xstrata share. The distribution of this presentation or any information contained in it may be restricted by law in certain jurisdictions, and any person into whose possession any document containing this presentation or any part of it comes should inform themselves about, and observe, any such restrictions. By attending the presentation and/or accepting or accessing this document you agree to be bound by the foregoing limitations and conditions and, in particular, will be taken to have represented, warranted and undertaken that you have read and agree to comply with the contents of this notice including, without limitation, the obligation to keep this document and its contents confidential.

Presentation Outline

• IsaMill™ Technology

− Development

− Operating Principles

• Ernest Henry Mine

− Background

− Life Extension

− Magnetite Plant

−Test Work

−Grinding Test Work

−Flow Sheet

• Conclusion

IsaMillTM Technology Development

• Development of IsaMillTM driven by inability to efficiently treat fine grained ore bodies

• Late 1980s, Xstrata required 7µm grind for new Pb/Zn ore bodies in Australia

• Conventional mining technologies previously tested, 1975-1990, but

− Too high power consumption to achieve target size

− Ball/tower mills ineffective below 20-30μm

− Negative influence of steel grinding on flotation

Broken Hill

0 40 micron

Broken Hill

0 40 micron

McArthur River

0 40 micron

McArthur River

0 40 micron

IsaMillTM Technology Development

A technology was found...

• Horizontal Bead Mills

− Technology existed in industries other than mining (Netzsch)

− Small scale

− Batch operation

− Very expensive and exotic media types

• Cross-over from manufacturing into minerals required:

− Much larger scale

− Continuous operation

− Ability to use cheap, local media

Source: AMIRA P336

Horizontal Bead Mill Technology

Other Technology

IsaMillTM Technology Development

• The first 3,000 litre, 1.1 MW IsaMillTM developed in partnership with Netzsch

• Affordable ceramic and local medias such as sand used

• First installed at Mount Isa Mine, 1994

• Enabling technology for McArthur River Mine, 1995

McArthur River Mine

IsaMillTM Technology Development

• Larger mills wanted

− Scale-up to 10,000 litres in 2003 (developed jointly with Anglo Platinum)

− Motor size increased from 1.1 MW to 3.0 MW

− Allows significantly higher throughputs and feed size (F80 up to 300µm)

− Scale up to M50,000 with 8MW motor in development

M10,000 IsaMillTM

IsaMillTM Technology Overview

IsaMillTM Technology Operating Principle

Media centrifuged to outside of grinding chamber by high centrifugal force (60g) generated inside the mill

Product separator pumps coarse

material back into the grinding

chamber

Discharge End

Multiple Stages of Grinding

Feed End

Coarser particles centrifuged into zone of high media concentration for size reduction before passing to next

stage of processing

Shaft rotating at high speed generating disc tips speeds of between 19–23 m/s

IsaMillTM Grinding Chamber

IsaMillTM Technology Operating Principle

The rotor fingers pump coarse particles and media back towards the feed end

of chamber for further grinding

A volume of slurry, equal to the mill feed flow, passes

through holes in the discharge ring and exits the mill

Material passing through the rotor disc holes moves across the

face of the discharge ring end plate towards the rotor fingers

Rotor Disc

Last Disc

Discharge Ring

Ground slurry passes through holes in the last disc to enter the classification zone

Ernest Henry Mine Background

• 38 km north-east of Cloncurry in the Mount Isa – Cloncurry mineral district of north-west Queensland

• Ore Reserve Estimate as at 30 June 2010

− 88 million tonnes Iron Oxide Cu Au deposit

− 1% Cu as chalcopyrite

− 0.5 g/t Au

− 23% Fe3O4

• Annual production

− 350,000 t Cu concentrate (100,000 t Cu)

− 120,000 ounces Au

− 1.2 Mtpa magnetite after expansion

Ernest Henry Mine Life Extension

• Extend life of EHM to at least 2024

− Transition from open pit to underground and associated magnetite plant through $589 million investment.

− Magnetite Plant

−Numerous studies on magnetite in ore

−Early studies focussed on magnetite removal

−Subsequent studies demonstrated viability of producing high grade magnetite

−Control PSD and liberate valuable material

Ernest Henry Mine AMMTEC Test Work- Grinding Efficiency

• Large tonnage magnetite plants- grinding energy efficiency important

• Test work looked at grinding circuit flow sheet optimisation

− Pilot autogenous primary milling

− Laboratory work (Levin test)

− Pilot secondary ball milling

− Laboratory and limited continuous secondary IsaMill™ testing

− Laboratory tertiary, limited continuous and pilot IsaMill™ test work

Ernest Henry Mine Previous Test Work IsaMill™ Selection

: EHM Tails Tower Mill™ vs IsaMill™ Test Work (Burford & Niva 2008)

Ernest Henry Mine AMMTEC Test Work- Grinding Efficiency

• Primary AG product 420µm

• Magnetic separator gangue rejection 40% of feed

• 2,200 tph feed to secondary grinding stage at a P80 of 770µm (the magnetic fraction coarser than gangue)

• Secondary Ball and IsaMill™ test work

Previous Test Work- Grinding Efficiency

IsaMill™ - Levin test comparison (David, Larson & Li 2011)

Ernest Henry Mine Test Work- Grinding Efficiency

Section Feed Rate

(t/h)

Specific Energy (kWh/t)

Installed Power (MW)

Annual Media Cost Estimate

($AUD million)

Autogenous Mill 770 µm Product

3800 8.5 40 $0

Single Stage Ball Mill 34 µm Product

2200 47 114 $86

Single Stage IsaMill™ 34 µm Product

2200 34 78 $57

Ball Mill 100 µm Product

IsaMill™ 34 µm Product

Total

2200

1720

12

13

34

24

58

$13

$11

$24

Circuit comparison (David, Larson & Li 2011)

Ernest Henry Mine Grinding Efficiency

• Magnetite plant

−1.2 million tons premium quality magnetite concentrate per annum

−Revenue stream from previous tailings stream

−Reducing amount of tailings

−Construction commenced in July 2010

−First magnetite concentrate produced in December 2010

Ernest Henry Mine Flow Sheet

Conclusion

• IsaMill™ technology has evolved from ultrafine grinding technology to mainstream and regrind technology and has wide acceptance in many metalliferous applications utilising the IsaMill™’s key advantages

− Energy efficiency

− High intensity

− Circuit efficiency

• These advantages have now been transferred to the magnetite beneficiation flow sheet

• Carefully considering the strengths of different technologies and exploiting these strengths has resulted in cost effective, efficient circuit design

Thank You

Questions