Electrochemical extraction mechanism of Nd on Ga-Al alloy electrode

Abstract

In order to reveal the extraction mechanism of Nd on Ga-Al alloy electrode, the electrode reactions and alloy formation between Nd(III), Ga(III) and Al(III) ions in different molten salt systems were studied by multiple electrochemical methods. The cyclic voltammetry curves measured in melts with different concentrations confirmed that only three intermetallic compounds were formed in both Ga-Nd and Al-Nd systems. The preferential interaction of Nd with Ga in Ga-Al-Nd ternary system was further verified by cyclic voltammetry curves with varying potential window. In particular, the co-reduction process of three ions was gradually determined by the comparison of electrochemical behaviour in different melts. In addition, the interfacial reaction of Nd(III) ion on liquid Ga-Al alloy cathode was investigated, and the corresponding exchange current densities were measured through galvanostatic pulse (0.0049, 0.0047, 0.0056 and 0.0055 A cm−2) and Tafel method (0.0029 A cm−2).