Cathodic Behaviour of Moisture in LiCl-KCl Eutectic Melt: Applications to Pyroprocessing

摘要

Presence of moisture in LiCl-KCl eutectic melt is known to be detrimental to its performance during electrorefining of metal fuels. Cyclic voltammetry was used to investigate the redox behaviour of LiCl-KCl eutectic melts containing moisture and compare it with chlorinated melts. Voltammetric signatures of one-step reduction of H_2O and HC1, adsorption of OH~-, and reduction of OH~- to form O~(2-) were observed. Voltammograms were evaluated based on difference between onset Li~+|Li potential and theoretical equilibrium potential of LiCl in LiCl-KCl eutectic melt and residual cathodic current density estimated in the potential range -1.50 to -2.0 V. This two-point criteria could be helpful in ascertaining purity of eutectic melts applicable for engineering scale applications involving bulk handling of LiCl-KCl eutectic mixture.