Managing the Giant A Mine Geologist s Perspective to the Mining of the Olympic Dam Deposit

Transcription

1 Managing the Giant A Mine Geologist s Perspective to the Mining of the Olympic Dam Deposit Charles Nzama and Mathias Kapo Superintendent Geology (Acting) and Geologist Mine Area 18 August 2014

2 Important Notices Reliance on Third Party Information The views expressed here contain information that have been derived from publicly available sources that have not been independently verified. No presentation of warranty is made as to the accuracy, completeness or reliability of the information. This presentation should not be relied upon as a recommendation or forecast by BHP Billiton. Forward Looking Statements This presentation includes forward-looking statements within the meaning of the U.S. Securities Litigation Reform Act of 1995 regarding future events and the future financial performance of BHP Billiton. These forward-looking statements are not guarantees or predictions of future performance, and involve known and unknown risks, uncertainties and other factors, many of which are beyond our control, and which may cause actual results to differ materially from those expressed in the statements contained in this presentation. For more details on those risks, you should refer to the sections of our annual report on Form 20-F for the year ended 30 June 2013 entitled Risk factors. Forward looking statements and Operating and financial review and prospects filed with the U.S. Securities and Exchange Commission. No Offer of Securities Nothing in this release should be construed as either an offer to sell or a solicitation of an offer to buy or sell BHP Billiton securities in any jurisdiction. Non-GAAP Financial Information BHP Billiton results are reported under International Reporting Standards (IFRS). References to Underlying EBIT and EBITDA exclude net finance costs and taxation for jointly controlled entities, and exceptional items. A reconciliation to statutory EBIT is contained within the profit announcement, available at our website SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 2

3 Important Notices Mineral Resources The FY2013 Mineral Resource information in this presentation is extracted from the report entitled BHP Billiton Annual Report 2013 published on 25 September 2013 and can be viewed at The company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement and, in the case of estimates of Mineral Resources, that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person s findings are presented have not been materially modified from the original market announcement. Competent Person for Olympic Dam Mineral Resource is S O Connell (MAusIMM) who is a full time employee of BHP Billiton. Competent Persons for Escondida District Mineral Resources are L Soto (MAusIMM), M Cortes (MAusIMM) who are employed by BHP Billiton and R Turner (MAusIMM) who is employed by Golder Associates. Mineral Resource classification (100% basis) for each province, where relevant, are listed in Table 1. Table 1 Province Measured Resource (Mt) Indicated Resource (Mt) Inferred Resource (Mt) Olympic Dam 1.02% Cu 0.3kg/t U 3 O g/t Au 0.84% Cu 0.27kg/t U 3 O g/t Au 0.70% Cu 0.23kg/t U 3 O g/t Au BHP Billiton interest Escondida district 0.67% Cu 0.52% Cu 0.47% Cu 57.5 % 100 SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 3

4 The Giant: Olympic Dam Deposit Location 560km NNW of Adelaide, South Australia Middle Proterozoic: Gawler Craton, Stuart Shelf geological province Occurrence Hosted within the Roxby Down Granite, Hiltaba Suite Iron Oxide Copper Gold deposit (IOCG): Key IOCG features OD Breccia Complex: Ore forming process Magmatic-hydrothermal brecciation, Fluid mixing and mineralisation Ore minerals and Cu species 2cm 2cm SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 4

5 The Giant: Olympic Dam Deposit Why giant? 6km by 3.5km, exceeding 1km depth Resource 1 : % Cu, 0.26 kg/t U 3 O 8, 0.31 g/t Au, 1 g/t Ag Largest underground mine in Australia FY13 Production 2 : 166kt Cu cathode, 4.1kt of U3O8, 113k oz Au and 880k oz Ag 1. A complete breakdown by Resource classification is provided on slide 3, table 1 2. Information extracted from the report entitled BHP Billiton Annual Report 2013 published on 25 September The report can be viewed at Chart depicts contained metal. Sources: Company Annual Reports, press releases and International Atomic Energy Agency (as at September 2012). Witwatersrand figure is BHP Billiton estimate and is approximate only. # Based on Codelco reported figures at 0.2% Cu cut-off grade. BHP Billiton Mineral Resources for Olympic Dam and Escondida district (includes Pampa, Pinta Verde and Chimborazo) are on a 100% basis. The FY2013 Mineral Resource information for Olympic Dam and Escondida district on this slide is extracted from the report entitled BHP Billiton Annual Report 2013 published on 25 September The report can be viewed at The company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement and, in the case of estimates of Mineral Resources, that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person s findings are presented have not been materially modified from the original market announcement. A complete breakdown by Resource classification is provided on slide 3, table 1. SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 5

6 The Olympic Dam Mine Mining method Mechanised sublevel open stoping with an integrated metallurgical processing plant Mine decision processes; from rock to cathode Data collection Interpretation and modelling MINE GEOLOGY Mine design and evaluation Production planning and scheduling Metallurgical processing, monitoring and reconciliation Mine geology objectives PROCESSING MINING PLANNING Defining ore body characteristics Optimise mine production design processes Supply quality ore to the processing plant SMELTING REFINING FINAL PRODUCT SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 6

7 Mine Area Management Mine Area Divisions 12 Mine Areas, actively mining in 8 Size varies, up to 5km 2 Division based on geological and operational factors Mineralisation and structural trends Ventilation districts Mine Geologists are custodians of mine areas 1km 1km SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 7

8 Mine Area Management Mine Area Geologist N mpg N mpg Technical expert in a mine area Accountable for quality of geological data Coordinates the geological functions Data collection and presentation Drill program design and management (>65km per year) Interpretations and models validation Primary contact for facilitating area specific technical queries 50m Drill program planning and design ~ 50m E Stope design processes 50m Infill drilling for resource model update Final resource model for mine design SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 8

9 Mine Geology Interpretations Resource Modelling Critical in stope design and metallurgical processes 26 elements assayed, models generated for: Metal grades, Cu:S and 15 process critical minerals Domain drivers deterministic Cu species models based on geological interpretations Importance of the Cu species models Relate to Cu:S ratio Ore grade distribution Relationship with other ore minerals Reliable local estimates: Mine design parameters Metallurgical processing and smelting parameters Models: K. Ehrig, 2013 SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 9

10 Mine Geology Interpretations Copper Sulphide interpretations Copper distribution has a broad spatial correlation with hematite alteration Provide the behaviour of the Cu sulphide species across the deposit Targeting tool for resource extension testing and resource category conversion drilling Rock Types Copper-sulphides interpretations 50m Combined Mine Area interpretations ~1km SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 10

11 Mine Geology Interpretations Geological Structures Preliminary geotechnical models are based on orientated surface drill core Models refined with underground drillcore, and groundtruthed via underground mapping (>20km per year). Underground mapping provides input data for mine area structural trends RQD data, faults, joints and veins Local and regional variations: mine area vs in-stope Structural data used in stability and performance assessments Ground support and blast packets designs Stope performance: over-break and under-break N(mpg) Mine regional structures ~ 1km 10 m Local structures interpretations 5 m SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 11

12 Grade Control Long Term Planning: 5 YP for volume and grade Grab samples are used for development headings and as a spot check for stope performance Managing of ore characteristics: Optimise ore quality management Blending during extraction Minimise impact on metallurgical performance Fe:SiO 2, Chlorite, Carbonates, Cu:S Exaggerated scale Comminution Flotation Leaching Smelting Refining low density (quartz, sericite) easily slimed (sericite, chlorite) acid soluble (sid, chl, flu); gelling minerals (chlorite) slow settling (sericite) low Cu:S ratio (py and cp); F-, Cl-, K-, Mg-, Zn-, Mo- minerals As-, Se-, Bi-, Te-, Sb- Pbminerals SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 12

13 Reconciliation Reserve model performance monitoring through the production value chain Blast packet grade assessments Daily production grade assessments Over-break/under-break assessments Reconciliation: effective sampling density (1:2500 tons) Process Plant to Ore Reserve (contained tonnes & grade) Final Product to Ore Reserve (recovered metal) Mineral Resource to Ore Reserve SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 13

14 Conclusion Olympic Dam is a giant deposit in both size and contained metals Effective management of the deposit has been achieved through its division into smaller manageable units Mine geologists are key to the collection, interpretation and dissemination of the data, and its application to the mining and metallurgical processes Planning decisions are based on key deposit-wide geological data At Olympic Dam, the decisions made by mine geologists have far-reaching consequences to the final outcome as they are carried through the whole mine value chain SC Nzama and MK Kapo, Mine Geology, Olympic Dam, 18 August 2014 Slide 14

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