MAXIMISING THE RECOVERY OF USEFUL METAL FROM ORES: THE CHALLENGE

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1 MAXIMISING THE RECOVERY OF USEFUL METAL FROM ORES: THE CHALLENGE Metal By-Products Recovery Conference, Brussels - 12 November 2015 Dr Chris Broadbent BSc, PhD, CEng, CEnv, MAE Director: Wardell Armstrong International Ltd Coordinator: FAME Project

2 Contents Resource V Reserve Polymetallic Processes Case Studies Au / Sb from sulphides Zn / Pb from Fluorspar In from Sn ore Conclusions

3 Resource V Reserve DEFINITIONS MINERAL RESOURCES: JORC Potentially valuable and for which reasonable prospects exist for eventual economic extraction. MINERAL RESERVES: Valuable and legally, economically and technically feasible to extract

4 Resource / Reserve Implication If there is no proven processing route there can never be a Reserve quoted and without a semi-known route it is difficult to justify some resource categories.

20 TH CENTURY PYRO-METALLURGICAL PROCESS THAT WAS

5 The Challenge (1) TO DEVELOP TRULY POLYMETALLIC PROCESSES HISTORICALLY VERY FEW PERHAPS THE ONLY 20 TH CENTURY PYRO-METALLURGICAL PROCESS THAT WAS A POLYMETALLIC PROCESS WAS THE IMPERIAL SMELTING PROCESS

6 The Challenge (2) SUSTAINABLE METAL PRODUCTION REQUIRES EFFECTIVE AND OPTIMISED RESOURCE UTILISATION RECOVERY OF ALL VALUABLE COMPONENTS i.e. RECOVERY OF METAL BY-PRODUCTS

7 The Challenge (3) ARE THERE EXISTING PROCESSING OPTIONS? DO WE ALWAYS KNOW WHAT IS PRESENT do we know what we are missing? IS THERE ACCESS TO FINANCE TO DEVELOP NEW TECHOLOGIES?

8 Case Study 1 RECOVERY OF GOLD AND ANTIMONY FROM SULPHIDE ORES (1) PROBLEM: LACK OF PRODUCTION CAPACITY FOR ANTIMONY OR ANTIMONY OXIDE PRODUCTION ALL FACILITIES OLD AND CAN T HANDLE ORES CONTAINING GOLD (i.e. GOLD NOT RECOVERED)

Case Study 1 GOLD / ANTIMONY (2) FUNDAMENTAL RESEARCH NEEDED FOR THE ROASTING ASPECTS OF A PROPOSED NEW PROCESS FLOW SCHEME CONCERNS: NO FACILITY IN EUROPE IDENTIFIED TO UNDERTAKE

9 Case Study 1 GOLD / ANTIMONY (2) FUNDAMENTAL RESEARCH NEEDED FOR THE ROASTING ASPECTS OF A PROPOSED NEW PROCESS FLOW SCHEME CONCERNS: NO FACILITY IN EUROPE IDENTIFIED TO UNDERTAKE PILOT SCALE ROASTING TESTS PROCESS FLOW DIAGRAM: Sb concentrate Roasting Fume Sb (+As / Zn) controlled quenching to precipitate various oxides smelting Sb 2 O 3 refining to pure Sb

10 Case Study 1 GOLD / ANTIMONY (3) KEY STEPS: ROASTING CONTROL OF QUENCHING TO PRECIPITATE METAL OXIDES Pb / Zn / As / Sb No European Facility therefore work undertaken at Hazen, Colorado

11 Case Study 1 GOLD / ANTIMONY (4) CALCINE: CONTAINS GOLD SUBJECT TO CIL PROCESSING FOR RECOVERY No Au Plant to produce Gold from sulphidic ores Product Sb Recover Au Phase II ores. Client raised finance to construct facility in Oman build Au Roaster Recovery plant for Refractory gold

12 Case Study 2 REMOVAL AND RECOVERY OF ZINC AND LEAD FROM FLUORSPAR ORES (1)

13 Case Study 2 REMOVAL AND RECOVERY OF ZINC AND LEAD FROM FLUORSPAR ORES (2)

14 Case Study 2 REMOVAL AND RECOVERY OF ZINC AND LEAD FROM FLUORSPAR ORES (3) CHALLENGE - FOR ACID GRADE FLUORSPAR IMPURITY LEVELS NEED TO BE VERY LOW - OVERALL 97% CaF 2 - But ppm levels Pb, Zn As

15 Case Study 2 REMOVAL AND RECOVERY OF ZINC AND LEAD FROM FLUORSPAR ORES (4) NEED HIGHLY EFFICIENT FLOTATION (OR OTHER SEPARATION TECHNIQUES). R&D NEEDED NEW REAGENTS? NEW TECHNIQUES?

Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (1) There are extensive tin (and tungsten) resources within the EC (e.g. UK, Spain, Saxony) and elsewhere (e.

16 Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (1) There are extensive tin (and tungsten) resources within the EC (e.g. UK, Spain, Saxony) and elsewhere (e.g. Syrymbet Kazakhstan) that are not exploited because their relatively low tin content prohibits economic production using current technology

17 Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (2) Current Smelting Technology - Needs Cassiterite concentrate containing 60%+ Sn

18 Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (3) Many Sn Resources contain Indium + Tantulum, gallium, germanium, scandium and niobium. BUT - Minor Metals can not be included in Reserve (and / or Resource) Statements. New Processing technologies Extractive Metallurgy are required to recover tin economically as well as the associated by-products. Development of hydro or pyro-metallurgical routes designed to maximise metal(s) recovery, recycled secondary material and minimise environmental footprint

Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (4) Mineral Processing - R&I Programmes such as FAME can help Extractive Metallurgy - Pyrometallurgy R&I

19 Case Study 3 RECOVERY OF BY-PRODUCTS FROM Sn ORES (4) Mineral Processing - R&I Programmes such as FAME can help Extractive Metallurgy - Pyrometallurgy R&I needed - Hydrometallurgy R&I needed Development of these technologies can lead to: Utilisation of more European ores; and Increase to Resource / Reserves Base

Conclusions Reserve for many By-product metals are often understated Under International classification schemes such as JORC this is always going to be the case unless there are proven recovery

20 Conclusions Reserve for many By-product metals are often understated Under International classification schemes such as JORC this is always going to be the case unless there are proven recovery methods Sustainable mining requires utilisation of all valuable components in an ore Truly poly-metallic Processing technologies are not common Need to Develop new technologies both mineral processing (beneficiation) a well as extractive (e.g. smelting) technologies to recover multi-element components General lack of experimental facilities in Europe H2020 is addressing some of the technology issues

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