Metallothermic reduction of Cerium Chloride in molten Salt using Li, Na, and Ca Metal

Abstract

Options for reducing purified metal chlorides to metallic form were evaluated in support of the development of a metal purification process based on the conversion of impure metal via hydriding followed by chlorination. Metallothermic reduction of CeCl3 was tested using Li, Ca, and Na as reductant metals with and without a molten salt solvent in MgO and Y2O3-coated MgO crucibles. The effects of added reductant metal form, crucible material and dimensions, and mixture hold times above Ce melting temperature were studied. Direct contact of Li and CeCl3 was ineffective due to their immiscibility. A low-density alloy was formed between Li and Ce using Li in a LiCl solvent. Na was ineffective at reducing CeCl3 to any measurable degree. The highest percent recovery (71.4 %) and consolidation of Ce was achieved when using Ca in a CaCl2-NaCl solvent with 99.8 % removal of CeCl3 from the salt. Side reaction with MgO crucibles was found to be at least partially responsible for reduced Ce recovery.