Anodic Behaviors of Noble Metals in Eutectic LiCl-KCl Melt

Abstract

The anodic behaviors of some noble metals and their alloys in dehydrated LiCl-KCl eutectic melt have been studied as a basic study on a new reprocessing process of spent UO2 nuclear fuel by an electrorefining technique. Palladium and Ru dissolved anodically as Pd2+ and Ru3+, respectively. Rhodium dissolved as Rh3+, and was passivated by surface film formation. The potentials where the steady dissolution current density was 10-3 A/cm2 were 3.02V for Pd, 3.08V for Rh and 3.12V for Ru, These values were more positive than the reported value of UO2. The anodic behaviors of Pt-Rh and Pd-Ru alloys were explained from those of each component, and no peculiar influence by alloying was seen. These results indicate that the noble metals and alloys can be separated from UO2 by leaving them in the anode by the control of the anode potential.