Hydrometallurgical Options to Add Value to Copper Projects and Operations

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1 Hydrometallurgical Options to Add Value to Copper Projects and Operations Peter Rohner Core Resources, Brisbane 24 th March 2010

Process engineering, design and flowsheet development Scoping and Feasibility Studies Technology Development Partner

2 Company Overview Highlights Specialist services: hrltesting (metallurgical laboratory operating over 25 years). Marketing of licensed processing technology (Albion Process). Process engineering, design and flowsheet development Scoping and Feasibility Studies Technology Development Partner Strong Technical Team: Hydrometallurgical expertise Flowsheet development with an economic focus and outcomes that can be engineered and operated Project development and commissioning experience

3 Copper Leach Flowsheets ROM ore In-Situ Leaching ROM ore ROM ore ROM ore Fines Size Dump/Heap Leaching Concentration (Gravity / Flotation) High Grade Concentrate Leach Acid Alkaline Tailings Lower Grade Concentrate Neutralisation Concentrate - Lower Impurities (e.g. As,Sb) Metal Recovery SX/EW SX/Crystallisation Precipitation Cementation Residue Products - Cathode - Sulphate - Cement - Oxide / Sulphide - Other By-products - Gold/Silver - Cobalt - Molybdenum - Rhenium - Indium - Uranium - Other

4 Copper Leach Flowsheets In-Situ Leaching Minerals Oxides Lixiviant Acid or Alkaline Not widely applied, needs the right geology and permitting e.g. Mount Gordon - QLD e.g. Florence, Arizona ex- BHP Copper still on hold Dump/Heap Leaching Minerals Oxides / Sulphides Lixiviant Acid or Alkaline (see AmmLeach later) Widely applied Pads Permanent / On-off Pads e.g. Tintaya, Peru (On-off Pad) e.g. Nifty - WA, Lady Annie - QLD

$Copper Leach Flowsheets Concentrate Leaching Minerals Oxides / Sulphides / Refractory Sulphides Lixiviant$

5 Copper Leach Flowsheets Concentrate Leaching Minerals Oxides / Sulphides / Refractory Sulphides Lixiviant Acid/Alkaline Processes - Pressure Oxidation - BIOX - GEOCOAT - CESL - Albion Process - Galvanox - Many others

6 Copper Leach Technologies AmmLeach For high carbonate ores and other high acid consuming gangue minerals (i.e. > 40kg acid/t of ore) Ammonia used (typically ~3kg ammonia/t of ore) Similar downstream circuits (SX/EW) and similar capital costs to acid leaching Pilot Plant run at Leon Copper Project - Argentina in 2007.

7 Copper Leach Technologies Pressure Oxidation Mount Gordon 1998 A$93M plant commissioned and ran until 2004, converted to concentrate production in 2004 as more chalcopyrite ore in feed. Currently on care and maintenance. 44,000 t/y Cu capacity. Freeport 2002 US$40M Bagdad plant commissioned converted to Molybdenum leaching plant in ,000 t/y Cu capacity US$240M Morenci plant commissioned currently shut down. 70,000 t/y Cu capacity..

8 Copper Leach Technologies Pressure Oxidation cont. CESL First demonstration plant for Vale in Carajás region of Brazil US$58M plant commissioned. 10,000 t/y Cu capacity. Pressure oxidation with chloride Chelopech 2011 US$80M plant with 20,000 t/y Cu capacity. Activox Nickel demonstration plant commissioned, but no copper plant.

9 Copper Leach Technologies Bacterial Leaching BIOX / BioCOP 2004 US$50M Alliance Copper (BHP Billiton and Codelco) plant commissioned t/y Cu capacity. The plant was shut down and was converted to smelter dust leaching. GEOCOAT No copper demonstration plant yet, a pyrite gold plant run in Africa. Oxidation is typically complete within 45 to 120 days, depending on the mineralogy. Need a low carbonate support rock. Temperature of a GEOCOAT heap ranges from 25-70oC. Working capital is significant.

Copper Leach Technologies Albion Process

10 Copper Leach Technologies Albion Process No copper demonstration plant yet although unit operations widely used. Mount Isa Mines dust leach plant gradually to be converted to Albion Plant. Uses fine grinding and oxidation at ~90oC under atmospheric pressure. Oxidation is typically complete within 12 to 24 hours, depending on the mineralogy.

11 Copper Leach Technologies Nikko Chloride Process ( N-Chlo Process. ) US$27M pilot plant being built in Perth now. 100 t/y Cu capacity Chloride leaching technology and solvent extraction technology Galvanox Process No demonstration plant yet. Uses pyrite to catalyze reaction. Atmospheric leach (~80oC). Pure sulphate medium (no chloride). No fine grinding. Fully compatible with conventional SX-EW.

12 Copper Leach Technologies Other Processes HydroCopper - Outotec Zangezur Copper-Molybdenum Combine CJSC project demonstration plant operation in in Finland. Erdenet Mining Corporation demonstration plant operation at Outotec Research Center, demonstration of the process technology at Pori, Finland in Chloride based technology, using chlorine gas and hydrogen. Intec Demonstration plant was constructed and operated during 1998 and 1999 in Sydney. Complex chemistry using sodium chloride-sodium bromide electrolyte. Copper EW from the cuprous (one electron) state.

13 Copper Leach Flowsheets Opportunities to Add Value Alternative products By-products In-situ acid production reduce acid cost Use of alternative neutralising materials reduce neutralising cost Impurity removal Integrated flowsheets Additional metal recovery Key drivers

14 Copper Leach Product Options Copper Cathode Larger scale projects Low/moderate power costs Remote / high transport costs Copper Sulphate Premium over metal Smaller scale projects Power costs higher Local demand zinc flotation, fertilizer plant, feedlot Cu2 Fe = Fe 2 Cu Other (Cement, Copper Sulphide, Copper Oxide) Copper cement concentrates or low cost scrap iron available Intermediate product market nearby or integrated flowsheet

15 Copper Leach By-product Recovery Smelters don t pay for many of these elements Leaching provides an opportunity to recover additional value e.g. Cobalt, Molybdenum, Rhenium, Indium, Uranium Oxide ore / Concentrate Air/ Oxygen Acid Leach Circuit Limestone Neutralisation Copper Solvent Extraction Advance to EW or Crystallisation Raffinate to Leach Bleed to by-product recovery and neutralisation

16 Copper Leaching In-situ Acid Production Generate excess acid in leaching circuit for oxide leach Separate pyrite oxidation circuit to generate acid - e.g. Sepon Underlying secondary and primary ore FLOTATION Flotation Tailings Recover more pyrite to leach circuit and oxidise Oxygen Acid Oxide ore Limestone Leach Circuit Neutralisation e.g. Freeport s Morenci and Bagdad POX plants HEAP LEACH Raffinate to Leach SX/EW Raffinate to Heap Leach

17 Alternative Neutralising Materials Turn neutralising stage from cost to a credit e.g. Use copper oxide ore (high grade fines) or copper oxide concentrate instead of limestone / lime. Concentrate Oxide ore Coarse Fines Oxygen Acid Leach Circuit Neutralisation HEAP LEACH Raffinate to Leach SX/EW Raffinate to Heap Leach

18 Impurity Removal Many large undeveloped copper deposits have significant impurity issues. Salobo, Brazil High Fluorine La Granja, Peru High Arsenic Tampakan, Philippines High Arsenic Nena, PNG High Arsenic Many other South American Copper Projects High Arsenic Core continues to be active further developing alkaline leaching technology to remove arsenic and antimony from copper concentrates.

19 Copper Leaching / Smelter Synergies Low Grade Concentrate Arsenic Rich Smelter Dust Iron Source Smelter Acid Oxygen Limestone Air Leach Circuit Neutralisation Liquid Solid Copper Solution to Copper Recovery Ferric Arsenate Gypsum Residue

20 Concentrate and Leaching Synergies Case Study Normal grade concentrate for sale vs. High grade concentrate for sale plus Low grade concentrate to leaching

21 Copper Recovery Copper Grade/Recovery Copper Grade - % Cu Liberated Chalcopyrite Perfect Separation Target Concentrate Grade - 25% Cu Max. Theoretical Recovery Copper Recovery %

22 Copper Recovery Copper Grade/Recovery Copper Grade - % Cu Liberated Chalcopyrite 30 Perfect Separation Plant Separation Liberated Gangue recovered by "Entrainment" or "True" Flotation 25 Target Concentrate Grade - 25% Cu 20 Plant Recovery Copper Recovery %

23 Copper Recovery Case Study Copper Grade/Recovery Copper Grade - % Cu Liberated Chalcopyrite 30 Target Concentrate Grade - 30% Cu 25 Concentrate for Sale 30% Recovery to Lower Grade Copper Concentrate - 7.5% Cu Concentrate for Leaching Copper Recovery %

24 Case Study Base Case 1,500,000 tonnes per year of 2% Copper. Conventional concentrate production 80% Copper recovery Sell concentrate 96,000 25% Copper grade (24,000 tonnes of Copper contained) Assumed Copper Price TC RC US$3.00 /lb US$50 /t US 5c /lb

25 Case Study Alternative Hydromet. Case 1,500,000 tonnes per year of 2% Copper. High grade concentrate production 60% Copper recovery Sell high grade concentrate 60,000 30% Copper grade (18,000 tonnes of Copper contained) Recover low grade concentrate and treat hydrometallurgically Low grade concentrate 120,000 tonnes 7.5% Copper grade ( 9,000 tonnes of Copper contained) Leach low grade concentrate 90% Copper recovery to Copper Sulphate product (8,100 tonnes of Copper contained) Total payable copper 26,100 tonnes (vs. 24,000 for base case)

26 Case Study Positives Additional 2,100 tonnes of copper recovered Higher revenue per tonne of copper (copper sulphate premium, higher payable lower deduct) Lower freight and treatment charges Additional ~$30M in net revenue (from above) Additional by-product revenue? Negatives Additional leach circuit and product to handle / sell Additional capital cost ~$50M, Additional leach circuit costs ~$10M Conclusion Robust project

27 Summary Key drivers that provide opportunities Can only produce dirty unsaleable concentrates Concentrate transport costs high - far from markets Low power costs Limestone/other neutralising material available and low cost Acid available and low cost (or low power cost) Existing infrastructure available (old oxide leaching operation SX/EW plant) Local demand for copper sulphate or intermediate Potential for by-products credits Significant recovery improvements

28 Questions?

Innovations in Copper Mineral Processing Technology

Innovations in Copper Mineral Processing Technology Peter Rohner Core Resources, Brisbane www.coreresources.com.au 17 th June 2014 Company Overview Highlights Specialist Metallurgical services: hrltesting