The Electrochemical Behavior of Neodymium(III) in FLiNaK Molten Salt on Pt Cathode

Abstract

The extraction of rare earth element neodymium (Nd) from LiF-NaF-KF (FLiNaK) molten salt by electrochemical reduction was introduced in this paper. Cyclic voltammetry (CV) and square wave voltammetry (SWV) results showed that Nd(III) can be reduced to Nd(0) by a one-step three electrons process: Nd(III) + 3e− → Nd(0), and the diffusion coefficient (D), the transfer coefficient (α) and the rate constant of standard reaction (k 0) of Nd (III) in FLiNaK melt at 823 K were calculated by CV and sem-integral analysis of the CV curves. The deposits of Nd on Pt cathode were confirmed by the potentiostatic electrolysis and characterized by SEM, EDS and XRD. The electrolytic products were composed mainly of Nd metal and two intermetallic compounds NdPt2 and NdPt. All of these results demonstrated the feasibility of electrolytic separation of Nd(III) on Pt cathode in FLiNaK molten salt.