Effect of the Temperature Conditions of Sulfation Process on Extraction of Rare-Earth Metals from Refractory Ore

摘要

Physical and chemical testing of sulfate product, obtained as a result of high-temperature treatment of ore from the Kundybai field with sulfuric acid mixture at 500 degrees C revealed the presence of cerium oxide corresponding to natural cerianite (CeO2). A mechanism of its formation is proposed, which includes a stage of cerium sulfate (Ce(SO4)(2)) formation followed by its dissociation to CeO2. The presence of this compound in the sulfate product allowed establishing the temperature required to further conduct the sulfation process and prevent cerianite formation.