The Electrolytic Reduction of Gd2O3 in LiCl-KCl-Li2O Molten Salt

In the common spent fuels, actinides and fission products are generally in the form of oxide, so direct dealing with oxide will be the most convenient way for spent fuel reprocessing. In this work, the electrolytic reduction of Gd2O3 has been studied in LiCl-KCl-Li2O (1 wt%) melts at different conditions, and the effect of sintering temperature on the porosity of Gd2O3 powder and the electrochemical behavior of Li2O in LiCl-KCl molten salt were investigated, too. The diffusion coefficient of O2- was calculated to be 2.0 x 10(-5) cm(2)center dot s(-1) in LiCl-KCl melts on the Mo electrode at 923 K by cyclic voltammetry (CV). The electrode process of Gd2O3 powder was also analyzed in LiCl-KCl-Li2O (1 wt%) melts, and the formation process of composite oxide LiGdO2 was determined. By the analysis of XRD and oxygen content characterization, it was suggested that after 74 h electrolysis (923 K, 3.40 V), the oxygen content of Gd2O3 cathode decreased from 12.25 wt% to 1.41 wt%, indicating 88.5% Gd2O3 was reduced to metal.

Automated summary

The study investigated the electrolytic reduction of Gd2O3 and the diffusion coefficient of O2- in LiCl-KCl melts, indicating that under specific conditions, 88.5% of Gd2O3 was reduced to metal.