1. 1 Facing the challenges of new low-grade orebodies with new economic circuit designs Malcolm Powell JKMRC - Queensland

2. 2 Driven by uncertainty & variability Modify process to respond to uncertainty (S. Begg) Vary processing routes to respond to known variability (Powell) Embrace uncertainty to develop a new range of economic/business options The variability of what comes your way will drive flexible processing Flexibility to create value

3. 3 DRIVERS Grade Energy Water Massive low-grade ore bodies Increasing demand GoldCopper price Comminution 36±10% mining energy Ballantyne 2011

4. 4 Considerably more challenging orebodies –rapid expansion by exploiting previously uneconomic deposits Rapidly increasing production costs cannot be sustained by continually increasing commodity prices –illustrated by the recent downturn in the industry A new mining era – a New mining industry

5. 5 processing of 50 to 100% more ore same amount of metal + finer grain structure - finer grinding more challenging recovery tweaking current technologies and relying on economies of scale will not turn the industry around Switch to considerably more efficient processing Reduction in grade Transform processing capability

6. 6 Throughput Collapse the rich orebody information to a standard single figure used in machine selection and circuit design Production prediction linked to conventional circuits average product size equipment gigantism Current approach Current approach is to extract less metal from more ore

7. 7 RISK is underperformance for the new orebodies Conventional circuits operated at historic inefficiencies Conventional design - locked in history Geometallurgical Modelling – at great cost and effort – No Upside Geometallurgical Modelling – at great cost and effort – No Upside

8. 8 The value-add of seeking upside In variability there is a lot of upside yet we choose to smooth and ignore blending and daily operation Upside lost opportunity in daily operation Limit average New average Process output

9. 9 Grade:0 - 3 Competence0.5 -1 Size (F80)40 – 130 mm Product requirement 40 – 100 µm Specific energy requirement 11 – 33 kWh/t Process fixed at 20±2 kWh/t ! Feed quality - extremely variable kWh/t Time10 yrs Conditional simulation

10. 10 Utilise the properties of the orebody – variability revolutionising our processing techniques Our new mantra: Selective mass mining with flexible processing Future approach - Utilise variability It is time to extract more metal from less ore

11. 11 Circuits designed to respond to variation in: –grade –competence –feed size distribution –liberation size by processing to varying: –target grind size –recovery options –cut-off grades Considerable, worthwhile challenge to ensure sustainability of our industry Future approach

12. 12 FlexiCircuits leverage ore variability to maximise resource utilisation Providing a range of alternative processing routes for a rock. Investigate processing options that provide extra capacity through sophistication rather than scale smart ore characterisation economic modelling innovative processing plant design FlexiCircuits

13. 13 A choice of processing routes respond to a wide variability in ore properties and throughput requirements –Shift workload slash processing costs and energy utilisation –Blast control –Reduced milling requirement –Progressive upgrade while enhancing overall recovery –Higher feed grades to flotation –Alternative recovery routes Novel Flexible Circuits

14. 14 Novel processing routes Novel or new application of equipment Devise and test the potential new processes Requires Ability to model equipment and circuit performance with confidence Enabling Technology Circuit Simulation Circuit response Individual machinery is useless Spot the HPGR

15. 15 Examples applied to novel flexible circuit design

16. 16 Uneconomic ore-body to viable Bulk sorter 60mm screen Gyratory Tag & load Smart blasting Flotation Ball mill Pebble crusher cyclone splitter Waste stockpile screen Low-grade SP Ore body knowledge Bulk grade detector Split stockpile Waste rejection Delayed processing

17. 17 fullupgrade% of full tph10000675668 recov, %8082103 Cu, tpd96095299 Power, MW1137264 specific power, kWh/t11.310.795 From uneconomic to viable 2 to 1 processing reduction 2x40 ft SAG, 2x26ft ball mill 1x42ft SAG 1x28ft ball mill

18. 18 Courtesy CSIRO Ore body knowledge Know what is coming your way & plan when Model Cells Contain processing parameters Courtesy CRC Ore

19. 19 Coarse Low Grade Coarse Waste Fine High Grade Ore Utilise variability – e.g. Blast Engineering by Grade Coarse low grade 19

20. 20 Ore body knowledge + flexible flowsheets Fine waste rejection Smart tag Process route Deferred stockpile Grade detector Know what is coming your way Making an orebody viable No grinding media 60% total energy Stable product + 3% recovery +25% metal production Upside 40% capacity AGSAG Reduced RISK

21. 21 Hybrid Circuit- HPGR - AG ball Mill Pump Sump SAG 5mm Coarse flotation Tailings concentrate 600 tph Middlings 3-product cyclone RoM 2000tph LG circuit / heap leach / waste Dry Clay clumps 70% energy Stable product Higher recovery Reduced RISK 50mm 20mm HPGR HPGR Feed 2200tph Wet Screen -1mm > water recovery < viscosity issues RoM 5000tph Dry fluidised bed separator Rejects Waste sorting Cone crush

22. 22 Model feed as average –little advantage in complex circuit Model variability of feed –advantages of hybrid flexible circuit over SABC circuit –response to ore variability –Multi-component simulation with advanced models Tuning variable processing to the variable processing regimes critical to advanced circuit development High quality ore body knowledge

23. 23 Hybrid + Stirred Mill Coarse flotation Middlings Grade-by- size sorter Grade splitter Multi-comp HPGR Multi-comp crusher Bimodal feed, multi-component SAG 3-prod cyclone, multi-comp Fine grinding Coarse recovery P80?

24. 24 Characterise ore –Base properties –Apply to variable circuits Model & Simulate –Multi-component –dynamic Pilot –larger capacity –process options Control –Dynamic simulation –test on large pilot plant (10 tph) Engineer –Physical layout –Turning concepts into reality Uptake

25. 25 Equipment suppliers & Engineering companies Transform complexity into elegance

26. 26 Exploiting lower grade and less favourable ore bodies Doubling comminution energy and processing equipment Unviable Geomet higher resolution of ore body knowledge tracks ore variability linked to flexible processing incorporating ore upgrade options Transform currently uneconomic resources into viable and reliable reserves New Mining Industry

27. 27 Design & build with todays technology, while allowing the uptake of tomorrows technology for tomorrows challenges. Ensure: Continued licence to operate Sustained profitability in the long-term Flexible circuits – Go Hybrid P.S. Invest in research, not mills

28. 28 Considerable team effort CMR Cape Town Rio de Janeiro TU Braunschweig Hacettepe Chalmers

29. 29 Resource definition (Geomet) Feeding into Flexible processing options Providing Increased recovery Greater resource value Future value Fresh & feasible Transform processing Conditional simulation Utilising Variability Process Drivers Geological model