Electrochemical reduction of UO2 to U in a LiCl-KCl-Li2O molten salt

An electrochemical reduction of UO2 to U in a LiCl-KCl-Li2O molten salt has been investigated in this study. A diagram showing equilibrium potentials (relative to Cl2/Cl-) plotted versus the negative logarithms of oxide-ion activity (pO2-) was constructed. The crushed UO2 pellets in the cathode basket of an electrolytic reducer were successfully reduced to U. The reduction of UO2 is proved to proceed mainly through chemical reaction with in situ generated Li and K at the cathode. The control of cathode potential is essential to prevent the deposition and subsequent vaporization of K metal at the cathode for the applications of a LiCl-KCl-Li2O molten salt as an electrolyte for the metal production from its oxide sources. (author)