RECOVERY OF CERIUM, NEODYMIUM AND LANTHANUM FROM MALAYSIAN MONAZITE USING OXIDATION AND SELECTIVE PRECIPITATION METHOD

Abstract

This study utilises a mixture of rare earth elements obtained from the Malaysian monazite through a series of processes from digestion to separation of non-radioactive and radioactive elements. The non-radioactive elements are the mixture of rare earth elements, mainly cerium, neodymium, and lanthanum. It is possible to separate cerium from other elements due to its ability to form +3 and +4 oxidation state compared to others. Therefore, the objective of this study was to compare the effectiveness of nitric acid HNO­₃ and hydrochloric acid (HCl) as dissolution media for the separation of cerium from mixed rare earth hydroxide concentrates. The oxidation using nitric acid media was found to be incomplete hence leading to poor separation. 2 M HCl was proven to be more effective, yielding a cerium concentrate of approximately 71.2% purity. The remaining neodymium and lanthanum were separated through selective precipitation and the products obtained were analysed using Energy Dispersive X-ray Fluorescence (ED-XRF).