Study on Aggregation Forming of Cathode Liquid Cerium Metal in Molten Salt Electrorefining Process

Abstract

The research on the electrorefining purification of metallic cerium is a useful way to lay the foundation for dry reprocessing technology of spent nuclear fuel in molten salt. This paper investigated the aggregation law and the effect of aggregation on the recovery percent of the cathodic liquid cerium metal in CeCl3-KCl melt. The simulation experiments showed that the cathodic metal cerium was not ingot metal but metal beads, which decreased the direct recovery percent (direct yield,Cathodic collection /Anode depletion) of cerium metal. The theoretical analysis and design experiments revealed that the cerium oxide film prevents the formation of cerium ingot metal. A compact metal cerium ingot was obtained by introducing chlorine gas, which was in situ produced by a pair of auxiliary electrodes. Moreover, the influence of electrolytic reduction current and four-electrode arrangement, and electrolytic current on the results of electrorefining was also deeply studied, and the direct recovery percent increased from ~ 60% to ~ 90%.