Nanofiltration-enhanced solvent extraction of scandium from TiO acid waste

Abstract

Scandium is a critical raw material with a technological potential to reduce transportation costs and CO2 emissions. However, global supply and market adoption are crucially impaired by the lack of high-grade Sc ores and recovery strategies. A tandem nanofiltration solvent extraction route is demonstrated to enable effective Sc recovery from real-world acid waste from the chloride TiO2 production route. The process involving several filtration stages, solvent extraction, and precipitation was optimized, ultimately producing >97% pure (NH4)3ScF6.