Separation of SmCl3 from SmCl3-DyCl3 system by Electrolysis in KCl-LiCl-MgCl2 Molten Salts

Pyrometallurgical reprocessing of spent nuclear fuel was now considered as one of the most promising options for an innovative nuclear fuel cycle. In this paper, the electrochemical behavior of Sm(III) and Dy(III) was studied by cyclic voltammetry in KCl-LiCl molten salts. Addition of magnesium chloride resulted in positive deposition potential of Dy(III), lower electrolysis temperature and higher recovery ratio of rare earth. According to different deposition potentials of Sm(III) and Dy(III), electrolysis in the molten KCl-LiCl-MgCl2 system constituted the main step in this reprocess, where SmCl3 was separated from the SmCl3-DyCl3 system at -2.20 V (vs. Ag/AgCl reference electrode) and the DyCl3 were formed the Dy-Mg alloys. It was proved that the main structures of the obtained alloys were Dy and DyMg3 without Sm by the analysis of XRD of alloys.