Electrowinning of cerium group metals from fused chloride bath

Abstract

Cerium group metals, namely, misch metal, lanthanum and cerium have been electrowon from their vacuum-dehydrated chlorides in fused sodium chloride-potassium chloride and lithium chloride-potassium chloride solvent. Temperature, cathode current density and composition of bath were optimised for high current efficiency and metal yield. In the case of lanthanum, current efficiency of 88% was achieved. The metals were free from inclusions and voids and analysed 99%⁺. The major non-rare earth metallic impurities were Fe, Mg and Al. The total gaseous impurities for lanthanum and misch metal were not more than 0·017%.