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

Аннотация

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°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.