Technique for enhanced rare earth separation

Abstract

A process is demonstrated for the efficient separation of rare earth elements, using a combination of selective reduction and vacuum distillation of halides. The large differences in the redox chemistry of the rare earth elements and in the vapor pressures of rare earth di- and trihalides are exploited for separation. Experimental proof of concept is provided for the binary systems praseodymium-neodymium and neodymium-samarium. This process enhances the separation factor for the isolation of samarium and neodymium from their mixture by more than an order of magnitude.