| Abstract Scope |
Rare elements such as the lanthanides, selenium, tellurium, or scandium are critical components of advanced materials for energy, structural components, or transportation. These low-tonnage elements are sourced together with other metals, an imposition often accomplished through tedious, complete hydrometallurgical dissolution of primary or secondary processing streams. Herein, we present selective sulfidation as a novel, high-temperature alternative for separation of rare by- and co-product elements, either as compounds or for further reduction. We demonstrate the technical promise of selective sulfidation as applied to selenium and tellurium recovery from copper minerals, scandium separation from iron, and rare earth element processing. Meanwhile, sulfidation chemistry enables the employment of emerging new electro-metallurgical methods of reduction such as molten sulfide electrolysis. We also include technoeconomic and life cycle analysis in the context of rare earth element processing via selective sulfidation, illustrating improved process economics and sustainability compared to conventional liquid-liquid hydrometallurgical solvent extraction. |