Extraction of Rare Earth Metals from Nd-based Scrap by Electrolysis from Molten Salts

Abstract

The possibilities of recovery of rare earth metals and alloys from Nd-based scrap by electrolysis from high temperature molten salts were investigated. The realization of such a process will eliminate the oxide or halide conversion steps, leading to a more effective and environmental process, as many hydrometallurgical steps are avoided. The NdFeB compound (which could be scrap from the magnet production or demagnetized spent magnet) is placed in the anode compartment from where the rare earth elements present in the material (Nd, Dy, Pr) will be anodically dissolved in the form of ions, which will be discharged at the cathode as metals and/or magnetic alloys. Different electrolyte compositions and temperatures are tested and the feasibility, kinetics, and efficiency of the process are evaluated.