Cesium and strontium recovery from LiCl-KCl eutectic salt using electrolysis with liquid cathode

Abstract

Deposition behaviors of Sr and Cs in various liquid cathodes, such as Zn, Bi, Cd, and Pb, were examined to evaluate their recovery from LiCl–KCl eutectic salt. Cations in the salt were deposited on the liquid cathode, exhibiting potential of −1.8 to −2.1 V (vs. Ag/AgCl). Zn cathode had successful deposition of Sr and exhibited the highest recovery efficiency, up to 55%. Meanwhile, the other liquid cathodes showed low current efficiencies, below 18%, indicating LiCl–KCl salt decomposition. Sr was recovered from the Zn cathode as irregular rectangular SrZn13 particles. A negligible amount of Cs was deposited on the entire liquid cathode, indicating that Cs was hardly deposited on liquid cathodes. Based on these results, we propose that liquid Zn cathode can be used for cleaning Sr in LiCl–KCl salt.

Keywords

• Recovery
• Strontium
• Cesium
• Liquid cathode
• LiCl–KCl salt
• Pyroprocessing