| Abstract Scope |
While the demand for rare earth elements (REEs) continues to grow, the supply situation for REEs has become increasingly volatile leading nations to develop new REE mines and explore alternative REE sources such as end-of-life products. Compositionally, these new REE sources can differ significantly from the usual REE ores for which extractive metallurgical practices are well-established. To bring new REE sources to market requires development of impurity removal practices to ensure minimal entrainment of impurities in REE concentrates and final products. This work comprehensively reviews recent progress in impurity removal during REE processing covering techniques including solvent extraction, ion exchange and adsorption, selective precipitation, and emerging techniques. Regarding impurities, most of the periodic table is covered with special attention given to iron, thorium, uranium, and aluminum. |