PRODUCTION OF A SCANDIUM-CONTAINING CONCENTRATE AND SUBSEQUENT EXTRACTION OF HIGH-PURITY SCANDIUM OXIDE THEREFROM

The invention relates to a technology for producing a scandium-containing concentrate from alumina production waste and obtaining a high-purity scandium oxide. The method comprises leaching red mud with a solution containing a mixture of sodium carbonate and sodium bicarbonate, sorbing scandium from the solution on a phosphorus-containing ion exchanger, and desorbing the scandium with a sodium carbonate solution to obtain commercial-grade reclaimed scandium, from which scandium concentrate is precipitated. Said concentrate contains no less than 15 mass% ScO, no more than 3 mass% TiO, and no more than 15 mass% ZrO, and the scandium in the concentrate is in the form of a mixture of the hydroxide Sc(OH)and the basic salt ScOHCCOx4HO. A method is also proposed that comprises dissolving a scandium-containing concentrate in sulfuric acid, removing the acid-insoluble precipitate, transforming the scandium into a precipitate, filtering, washing, drying, and sintering to obtain a scandium oxide precipitate. After the acid-insoluble scandium precipitate is removed, the scandium is precipitated from the filtrate, removed by filtration, and washed, the binary salt is dissolved in water, and scandium hydroxide is precipitated with caustic soda. The cake is then transformed into scandium oxalate, removed by filtration, and washed with water, and the scandium oxalate is calcined to obtain scandium oxide with a purity approaching 99 mass %.