Sulphide Oxidation Typical Albion Process leach test results Low - PowerPoint PPT Presentation

Sulphide Oxidation • Typical Albion Process leach test results Low Oxidation High Oxidation 100 90 80 70 Gold Recovery (%) 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Sulphide Oxidation (%) 21

Commercial Plant – Flowsheet & Equipment 22

Commercial Plant • Integrated Flowsheet Bulk Pyrite Con Ultrafine grind Albion Limestone Process Albion Leach Oxygen Plant Slurry Cooling Barren Carbon NaCN Cyanide Leach Elution Loaded Carbon GOLD DORE Thickening Underflow Cyanide Destruct Tailings 23

Commercial Plant • Albion Process Reactor Atmospheric leaching tank  Centrally mounted impeller  Dual hydrofoil agitators  Ring of supersonic oxygen spargers at  base of reactor Fitted with baffles and slurry riser  Staged limestone slurry dosing from  limestone ring Autothermal operation  No internal cooling coils or flash stages  24

Commercial Plant • Albion Process Plant  Low cost materials due to neutral pH nature of slurry (304/316 and duplex steels LDX 2101)  Low cost and efficient oxygen mass transfer through combination of agitation power and sparger pressure  Conventional field erected or modular tanks  Xstrata Technology now offers options for prefab modular tanks that the elements can be shipped in sea containers 25

Capital & Operating Costs 26

Capital & Operating Costs • Generic Case Study Inputs Feed Type Concentrate Treatment rate 219,000 tpa 100 Gold grade 20.0 g/t 90 80 Sulphide sulphur grade 40.0% w/w 70 Gold Recovery (%) Principle gold bearing mineral Pyrite 60 Albion Process Design Basis 50 Sulphide sulphur oxidation requirement* 70% 40 30 Sulphide sulphur oxidation rate* 61,320 tpa 20 CIL Process 10 Gold recovery 90.0% 0 Gold production 126,752 oz/y 0 10 20 30 40 50 60 70 80 90 100 Sulphide Oxidation (%) Project Input Costs Power 100 US$MWh Limestone 50 US$/t Oxygen 45 US$/t Weighted average labour cost 50,000 US$/person 27

Capital & Operating Costs • Generic Case Study Order of Magnitude Capex ( ± 30%) Fully Installed Albion Process Plant Area Base 70% SOx Mechanical equipment Structural Steel 600 tpd Electrical distribution and plant substations (US$) Piping, valves, launders Instrumentation and control $ 38,200,000 Concrete, ring beams and bunding ALBION PLANT Buildings and Architectural Civil Works (assuming level site) $ 24,500,000 EPCM Labour OXYGEN PLANT EPCM Expenses Commissioning Labour Commissioning Expenses Insurances TOTAL COST $ 62,700,000 Temporary Works First fills and Reagents Spares Contingency NB: Oxygen plant is outside Albion Process and Xstrata Technology scope of supply Unit Operations Oxygen plant costs are order of magnitude costs IsaMill Fine Grind Capex costs converted to operating cost (discount rate 12.5% Leaching Neutral Slurry Thickening over 10 years) = 185 US$/t SOx Slurry Cooling 28

Capital & Operating Costs • Generic Case Study Order of Magnitude Opex ( ± 30%) Category US$/t con US$/oz Au Dist'n Maintenance Power (IsaMill) 6 10 7% supplies & Power (Rest of plant) 2 3 2% consumables Power Limestone 45 77 50% Power (Rest 3% (IsaMill) Oxygen 29 50 32% of plant) 7% 2% Labour 6 10 6% Maintenance supplies & consumables 3 5 3% Labour 6% Total 90 155 100% NB: Oxygen Oxygen plant is outside Albion Process and Xstrata Technology scope of supply 32% Oxygen plant costs are order of magnitude costs that will require validation from vendors Limestone 50% Gold price US$/oz 1,000 750 500 Gold equivalent opex oz/y 19,669 26,226 39,339 g/t Au 2.8 3.7 5.6 Opex ~19.7M US$/y SOx units % w/w sulphide 28.0 28.0 28.0 ~320 US$/t SOx g/t Au per % SOx 0.10 0.13 0.20 29

Capital & Operating Costs • Generic Case Study- Sensitivity to Limestone and Power Direct Opex Costs 321 US$/t SOx Amorised Capex Costs 185 US$/t SOx Limestone: US$50 /t 505 US$/t SOx TOTAL Power: US¢10/kWh 245 US$/oz Au Oxygen: US$45/t Discount Rate 12.5% Project Life 10 years Direct Opex Costs 261 US$/t SOx 185 US$/t SOx Amorised Capex Costs Limestone: US$40/t TOTAL 445 US$/t SOx Power: US¢8/kWh 215 US$/oz Au Oxygen: US$35/t Discount Rate 12.5% Project Life 10 years Direct Opex Costs 205 US$/t SOx Amorised Capex Costs 185 US$/t SOx Limestone: US$30/t 390 US$/t SOx TOTAL Power: US¢6/kWh 189 US$/oz Au Oxygen: US$27/t Discount Rate 12.5% Project Life 10 years 30