1 MEAB Chemie Tecknik GmbH, Aachen/Germany POTENTIAL of SCANDIUM SUPPLY from ORES and INDUSTRIAL PRODUCTS in the NEAR FUTURE By Dr. Şerif KAYA (presenter)1,2, Bengi YAGMURLU1,2, Dr. Carsten DITTRICH1, Prof. Dr. Bernd FRIEDRICH2 1 MEAB Chemie Tecknik GmbH, Aachen/Germany 2 RWTH Aachen University, IME Process Metallurgy and Metal Recycling, Aachen/Germany

OUTLINE Scandium Applications/Sources: Current Sc Sources and Supply/Demand Issues: Scandium from Bauxite Residues: Scandium from Lateritic Ni-Co Ores: Companies Developing New Sc Projects: References: The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 2

Al-Sc & Al-Sc-Mg Alloys APPLICATIONS of Sc In the Near Future 3D Printing Tech. Al-Sc & Al-Sc-Mg Alloys Solid Oxide Fuel Cells Lasers & Lighting The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 3

commercial applications will certainly boom! SOURCES of Sc No primary mine production yet! As a by product during Iron-Uranium Production, As a by product during Tungsten Production, As a by product during Titanium Production, As a by product during Zirconium Production, As a by product during REE’s Production, [1,2] Supply is only ~5-12 tons/year in the form of Sc2O3 and the price is too high (2000-4500 $/kg 99.9 Sc2O3) for commercial applications. [3] Currently, only used in appliations where performance is much more important than the price (military/sporting goods, space appl. etc.) However; when consistent, abundant, reliable and low cost scandium supply is achieved, commercial applications will certainly boom! Short term promising source for the huge and urgent scandium need of the industry? The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 4

Greek Bauxite Residue Composition Sc from Bauxite Residues (Red Mud) Worldwide there is an annual bauxite residue production of 120 million tonnes (dry matter) and a total inventory of 3 billion tonnes, stored in huge tailing ponds. Sc is enriched ~2 times in the BR and represents >95% of the economic value of rare earth elements in red mud. [4] Greek Bauxite Residue Composition [5] [5] Environmental concerns and huge economic potential, force the exploitation of Red Mud for Sc recovery. The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 5

Sc from Bauxite Residues (Red Mud) Environmental concerns and huge economic potential, force the exploitation of Red Mud for Sc recovery. Pyro-Hydrometallurgical Approach Reductive Roasting & Magn. Separation Reductive Smelting of BR for Fe rec. (Pig Iron) > 98% Sc reported in the slag Leaching & Recovery by IX-SX Hydrometallurgical Approaches Selective Leaching (mineral acids: H2SO4, HCl, HNO3), (carbonate leaching), (Ionic liquids), IX - Solvent Extraction (Recovery & Purification) The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 6

Sc from Bauxite Residues (Red Mud) ORBITE Alumina Flowsheet [6] RUSAL Flowsheet [7] Red Mud Red Mud HCl Leaching S/L Separation AlCl3.6H2O Crystallization Impurity Hydrolysis Sc/REE Recovery Al2O3 AlCl3.6H2O Calcination Impurities Carbonate Leaching (NaHCO3 + CO2) NaHCO3 CO2 HCl Leach Residue (Si, Ti, etc.,) S/L Separation Impurity Hydrolysis I Ti, Zr Hydrolysis II NaOH Sc Concentrate > 99% Sc2O3 Further Purification Pilot Plant in Urals Al Smelter ~95 kg Sc2O3 per year The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 7

Two main Ni-Co Recovery Options Sc from Lateritic Ni-Co Ores and Residues When compared to Bauxite leaching with NaOH during Al production; 80-95 % of Sc is reported to be dissolved together with Ni-Co during Sulphuric Acid Pressure Leaching depending on the ore mineralogy. [8, 9] Two main Ni-Co Recovery Options 1-MSP (Mixed Ni-Co Sulfide Ppt.) Method 2-MHP (Mixed Ni-Co Hydroxide Ppt.) Method The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 8

Sc from Lateritic Ni-Co Ores and Residues 1-MSP (Mixed Ni-Co Sulfide Ppt.) Method Laterite Ore HPAL-Autoclave pH ~3.0 Primary Neut. and S/L Separation Leach Residue + Hydrolyzed Impurities H2S Ni-Co Sulfide ppt. Ni-Co Sulfide Sc containing soln. Sc Upgrading by IX Sc Precipitation pH ~5.0 Re-leaching Sc Recovery by SX Sc Recovery by IX or SX The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 9

Sc from Lateritic Ni-Co Ores and Residues 2-MHP (Mixed Ni-Co Hydroxide Ppt.) Method Laterite Ore HPAL-Autoclave Primary Neut. and S/L Separation Leach Residue pH 2.75-3.0 pH 4.75-5.0 Impurity Removal and Sc ppt. 4-7 times Sc enrichment Ni-Co Hydroxide ppt. Re-leaching pH 7.0-8.0 Sc Recovery by IX or SX The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 10

Sumitomo Metal Mining Co. Sc from Lateritic Ni-Co Ores and Residues Companies Developing New Sc Projects Companies Having Operating HPAL Plants for Ni-Co Production Sumitomo Metal Mining Co. Coral Bay & Taganito MSP HPAL Plants (Philipinnes) In 2013, Pilot Plant constructed in Coral Bay 10 kg/month Sc2O3 capacity, and the industrial plant having 7.5 ton/year Sc2O3 capacity is planned to start production in 2018. Proven Process in Pilot-Scale, Patent Applications for IP. META Nikel-Kobalt A.Ş. Gördes MHP HPAL Plant-Eskişehir Yunusemre Deposit (50-120 g/ton Sc) Patent Applications for IP. Proposed product is not only oxide but also different Sc compounds especially fluorides [10]. No pilot plant announced yet. The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 11

Sc from Lateritic Ni-Co Ores and Residues Companies Developing New Sc Projects Lateritic Ni-Co resources seem highly advantageous; Urgent, Reliable, Sufficient, Long-term, Reasonaly priced, Sustainable, Sc Production in the near future! [11] The 2nd Conference on European Rare Earth Resources, 28-31 May, Santorini, Greece 12

REFERENCES Wang W. and Cheng C.Y. (2011). "Separation and purification of scandium by solvent extraction and related technologies: A review." J. Chem. Technol Biotechnol 86 (10): 1237-1246. Gambogi J. (2017). USGS Mineral Commodity Summaries, January 2017, United States Geological Survey (USGS): 146-147. Riggall S. (2015). Australian scandium supply - A paradigm shift for a strategic metal AeroMat'15, Long Beach, California ASM International. Binnemans K., et al. (2015). "Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review." Journal of Cleaner Production 99: 17-38. Dimitrios P. (2016). Recovery of Metals from Bauxite Residues. REDMUD Summer School, 'From Bauxite to Aluminium', Leuven, Belgium. Orbite Technologies Inc., The Orbite Process. Retrieved 11.05.2017, from http://www.orbitetech.com/English/technology/the-orbite-process/default.aspx. Petrakova O. V., et al. (2015). Improved Efficiency of Red Mud Processing through Scandium Oxide Recovery. Bauxite Residue Valorisation and Best Practices, Leuven, Belgium. Haslam H. and Arnall B. (1999). An investigation into the feasibility of extracting scandium from nickel laterite ores. Proceedings of ALTA 1999 Nickel/Cobalt Pressure Leaching & Hydrometallurgy Forum, Perth, Australia, ALTA Metallurgical Services. Kaya Ş. and Topkaya Y.A. (2016). Extraction behaviour of scandium from a refractory nickel laterite ore during the pressure acid leaching process. Rare Earths Industry: Technological, Economic and Environmental Implications. Ismar Borges de Lima and Walter Leal Filho: 171-181. İplikçioğlu A.S. and Topkaya Y.A. (2015). Recovering scandium and derivatives thereof from a leach solution loaded with metals obtained as a result of leaching lateritic ores comprising nickel, cobalt and scandium, and secondary sources comprising scandium. WO2016209178. Ricketts N. and Duyvesteyn W. (2017). The current status of scandium supply projects and their technical challenges. ALTA'17 Nickel-Cobalt-Copper Conference 20-27 May, Perth/Australia, ALTA Metallurgical Services. 13

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