Electrochemical extraction of neodymium by co-reduction with aluminum in LiCl–KCl molten salt

Abstract

The electrochemical behavior of Nd(III) ions in LiCl–KCl and LiCl–KCl–AlCl3 melts on a Mo electrode at 723K was studied by various electrochemical techniques. The results showed that Nd(III) ions are reduced to Nd(0) through two consecutive steps, and the underpotential deposition of neodymium on pre-deposited Al electrode formed two kinds of Al–Nd intermetallic compounds in LiCl–KCl–AlCl3 solutions. The electrochemical extraction of neodymium was carried out in LiCl–KCl–AlCl3 melts on a Mo electrode at 873K by potentiostatic and galvanostatic electrolysis. The extraction efficiency was 99.25% after potentiostatic electrolysis for 30h. Al–Li–Nd bulk alloy was obtained by galvanostatic electrolysis. X-ray diffraction (XRD) suggested that Al2Nd and Al3Nd phases were formed in Al–Li–Nd alloy. The microstructure and micro-zone chemical analysis of Al–Li–Nd alloy were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), respectively.