Extraction of Sm by Co-Deposition Method in LiCl-KCl-GaCl₃ Molten Salt System

The electrochemical behaviors of SmCl₃ and SmCl₃-GaCl₃ on Mo cathode in LiCl-KCl molten salt were studied by cyclic voltammetry(CV), square wave voltammetry(SWV), and open circuit chronopotentiometry(OCP). The electrochemical results of SmCl₃ on Mo cathode show that Sm³⁺ undergoes a single electron transfer reaction in the LiCl-KCl molten salt system, and can only be reduced to Sm²⁺. The diffusion coefficient of Sm³⁺ and apparent standard potential of Sm³⁺/Sm²⁺ at different temperatures were calculated. The co-deposition of SmCl₃ and GaCl₃ results indicate that Sm and Ga can form SmGax alloys. The phase of SmGa₂ that is obtained by electrolyzing of LiCl-KCl-SmCl₃-GaCl₃ at -1.600 V is confirmed by XRD and SEM&EDS. The results above reveal that on the addition of GaCl₃, Sm can be  effectively extracted from the LiCl-KCl molten salt system.