Chlorination of UO2, PuO2 and rare earth oxides using ZrCl4 in LiCl–KCl eutectic melt

Abstract A new chlorination method using ZrCl 4 in a molten salt bath has been investigated for the pyrometallurgical reprocessing of nuclear fuels. ZrCl 4 has a high reactivity with oxygen but is not corrosive to refractory metals such as steel. Rare earth oxides (La 2 O 3 , CeO 2 , Nd 2 O 3 and Y 2 O 3 ) and actinide oxides (UO 2 and PuO 2 ) were allowed to react with ZrCl 4 in a LiCl–KCl eutectic salt at 773 K to give a metal chloride solution and a precipitate of ZrO 2 . An addition of zirconium metal as a reductant was effective in chlorinating the dioxides. When the oxides were in powder form, the reaction was observed to progress rapidly. Cyclic voltammetry provided a convenient way of establishing when the reaction was completed. It was demonstrated that the ZrCl 4 chlorination method, free from corrosive gas, was very simple and useful.