Selective Formation of Rare Earth-Nickel Alloys via Electrochemical Reactions in NaCl-KCl Molten Salt

摘要

Toward the establishment of the electrochemical recovery process of rare earth elements from used magnet scraps, selective electrochemical formation of RE-Ni alloys (RE = Nd, Dy, and Pr) was investigated in molten NaCl-KCl added with NdCl_3, DyCl_3, and PrCl_3 (0.50mol% each) at 973 K. Alloy samples were prepared by potentiostatic electrolysis using Ni plate electrodes at various potentials. Compositions of the formed alloys were analyzed by EDX, and separation factors defined as x_(Dy)/(x_(Nd) + x_(Pr)) were compared. High separation factors of 9.9 and 22.9 were obtained at 0.42 V and 0.45 V (vs. Na~+/Na), respectively, indicating the possibility of effective separation and recovery of REs from the used magnet scraps.