Nuclear Technology / Volume 162 / Number 2 / May 2008 / Pages 192-198
Technical Paper / First International Pyroprocessing Research Conference
The chemical behavior of lanthanide oxides has been studied both for the electrolytic reduction process and the electrorefining process. At high concentration of Li2O in LiCl, lanthanide oxides reacted with Li2O to form mixed oxides, LiLnO2 (Ln = lanthanides), which decomposed to the starting materials at relatively low Li2O concentration. The chemical behavior of lanthanide oxides under the condition of electrorefining process was investigated by optical fiber spectrophotometry and X-ray diffraction. Lanthanide oxides reacted with U3+ to produce Ln3+ and UO2. The solubility of lanthanide oxides was measured under the electrolytic reduction and the electrorefining condition. All of the lanthanide oxides except Eu2O3 had relatively low solubility values in LiCl-KCl eutectic mixture at 450°C. Electrochemical behavior of Br-, I-, and Se2- in LiCl was also investigated by cyclic voltammetry and by X-ray diffraction. All of the anions reacted with platinum anode and gave platinum compounds.