The II-VI Selective-Ion Recovery (SIR) Technology includes the use of a composite extractant-enhanced ion-exchange resin to extract scandium (Sc) from acidic solution or slurries, and its subsequent recovery as Sc concentrate. The work presents the applicability of the SIR process for recovery of Sc from acidic waste solution from the carbothermal chlorination processing of titanium ores. It is known that titanium (Ti) loads to the SIR resin so the solution pre-treatment to remove Ti was required to increase the capacity of the resin for Sc loading. Precipitation experiments were carried out to determine the required pH and reagent at which Ti is preferentially precipitated to produce a Pregnant Leach Solution (PLS) while maintaining Sc in solution. Under the optimized conditions, the generated PLS was used to develop the adsorption isotherm and loading profile. It was determined that the Sc loading capacity could be as high as 20,000 mg/L SIR resin. Under this project, the SIR pilot plant was built. The acid waste solution was treated to remove Ti. The solution from the Ti Removal step contained low concentration of Ti, Th, Nb and Zr. During the pilot plant operation, 95% recovery of Sc through SIR IX was achieved. The crude Sc concentrate produced contained about 20% Sc. The research leading to these results has received funding from the European Community’s Horizon 2020 SCALE Programme (H2020/2014-2020/No. 730105).
Link to the paper : Recovery of Scandium from Titanium Tailings Solution Using II-VI SIR Technology