Preliminary assessment of hydrometallurgical processes for the recovery of rare earth (Y), Sn, Ti, Zr, Nb and Ta of a polymineralic concentrate

The objective of this work was the recovery of tin, tantalum, rare earths(yttrium), niobium and zirconium contained in a low grade polymineralic concentrate from Pitinga (AM) mine . A comparative study was carried out between the routes of acid baking and alkaline/hydrochloric leaching. The best results were obtained for the acid baking route reaching values of 79% for Nb, 32% for Y and 26% for Ta. The statistical analysis of the acid baking step showed that the temperature of the oven was the most significant variable in the recovery of the analyzed elements, suggesting that the its reduction could favor an improvement in the extraction, mainly of Nb and Ta. The route using alkaline/hydrochloric leaching was more selective particularly for Y and Th, with maximum extraction values of 43.0% and 27.5%, respectively and with reduced extractions for the other elements analyzed. (author)