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

Abstract

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.

Keywords

• sm
• co-deposition
• electrochemical behavior
• molten salt
• dry reprocessing