Development of Scandium-Recovery Process from Titanium-Smelting Residue

Residues from titanium smelting tend to contain scandium. The scandium is discarded because no suitable process exists for its recovery from the residue. Valuable-metal recovery from discharged residue is critical for environmental conservation and to achieve a sustainable society. Since 2015, JX Nippon Mining & Metals has been developing a process for scandium recovery from the residue of a titanium-smelting process. The process consists of the following steps: scandium concentrating by classification or neutralization, selective scandium leaching, impurity removal by neutralization, solvent extraction of scandium by using D2EHPA, purification, and roasting. We optimized the above steps to achieve an effective process to obtain scandium oxide (Sc2O3). In this paper, we introduce results from the bench-scale test of the scandium recovery flowsheet developed by JX Nippon Mining & Metals.