Scandium Extraction from Bauxite Residue Using Sulfuric Acid and a Composite Extractant-Enhanced Ion-Exchange Polymer Resin

This work presents the results of scandium extraction from Greek Bauxite Residue (BR) using sulfuric acid as the leaching agent and a composite extractant-enhanced ion-exchange resin for a new novel, selective-ion recovery (SIR) process developed by II-VI. The BR produced in Mytilineos's plant contains approximately 75-130 mg/kg of Sc and given the plant's current production capacity, more than 100 t of Sc are discarded each year within the BR stream. The optimum conditions for selective Sc extraction from BR were determined at lab scale in conjunction with the efficiency in Sc uptake by the resin. Under the SCALE research project, a BR leaching pilot plant (Mytilineos) and Sc extraction pilot plant (II-VI) have been established and operated in Mytilineos's plant to demonstrate this process.