ABSTRACT
Sixty years ago, solvent extraction (SX) was employed mainly as an analytical tool for the separation and analysis of elements with very similar chemical properties. The discovery and isolation of the lanthanide and actinide elements provided impetus for the further development of these technologies, as the closely related properties of these f-group elements stretched the boundaries of knowledge in this young field (Nash 1993). During World War II, the Manhattan Project required significant quantities of high-purity isotopes of uranium and plutonium. The chemistry and engineering developed for these bulk separations were the first industrial applications of SX (Jenkins 1979; Seaborg 1963).
