RECOVERY OF DYSPROSIUM(DY) FROM LIQUOR OBTAINED THROUGH COLUMBITE LEACHING

Abstract

The processing of columbite ore is a significant source for obtaining steel alloys, iron, niobium, and tantalum. However, a residue rich in rare earths is produced during the leaching stage of columbite. In this context, the aim of this research project is to develop more sustainable technological routes for purifying and recovering dysprosium from this residue using various purification techniques such as solvent extraction, selective precipitation, and chelating ion exchange resins to obtain dysprosium solutions with lower concentrations of impurities such as iron, aluminum, and silicon. The research phases of the project involve: I) characterization of (a) the organic extractants to be used, (b) the received residue and (c) ion exchange resins; II) parameter studies for the purification and separation of dysprosium present in the residue through solvent extraction; III) batch and fixed-bed column ion exchange tests; IV) study of selective precipitation for impurity removal to determine if the purified liquor can be used in subsequent auxiliary techniques. Finally, the obtained liquors will be precipitated and subsequently subjected to calcination stages to produce dysprosium oxide. This project is linked to the thematic project FAPESP 19/11866-5.