Electrochemical behavior and extraction efficiency evaluation of Gd in chloride molten salt system

Abstract

The electrochemical behavior and thermodynamic properties of GdCl 3 in LiCl-KCl molten salt system on both Mo and Al electrodes at 773 K were investigated. An open circuit chronopotentiogram was used to determine the equilibrium potentials and standard apparent potentials of the Gd(III)/Gd(0) system in the temperature range 723-873 K. The results showed that the equilibrium potentials and apparent standard potentials became positive with increasing temperature. The activity coefficients of GdCl 3 were calculated at different temperatures. The depolarization values were calculated by steady state polarization tests, and the theoretical extraction efficiency was obtained at 773 K. Potentiostatic electrolysis was performed to extract gadolinium from LiCl-KCl-GdCl 3 molten salt on Al electrodes at -1.5 V. The extraction efficiency was about 94.22% after 20 h. The Al 3 Gd phase was identified in the deposit by X-ray diffraction (XRD).