METHOD OF PROCESSING RED MUD TO PRODUCE SCANDIUM OXIDE Russian patent published in 2025 - IPC C22B59/00 C22B3/12 C22B3/20 C01F17/212 C22B7/00 

FIELD: chemistry.

SUBSTANCE: invention relates to processing red mud in order to obtain scandium oxide. Method involves filtration of red sludge from the liquid phase, repulping the red sludge cake with a soda-bicarbonate solution, bubbling the sludge pulp with a gas-air mixture to activate scandium compounds in the sludge, carbonizing leaching of slime pulp, filtration to produce production scandium-bearing solution. Obtained solution is mixed with alkali-aluminate solution to produce precipitate, which is filtered and repeatedly leached to obtain scandium-containing alkali-aluminate solution and insoluble precipitate. Precipitate is repeatedly leached to obtain scandium-containing soda-bicarbonate solution. Scandium-containing alkali-aluminate solution and the scandium-containing soda-bicarbonate solution are mixed to obtain a concentrate, from which scandium is extracted into the sulphuric solution by two-stage sulphuric acid leaching. From the scandium-containing solutions filtered after 1st and 2nd stages, scandium sulphate is deposited, which is treated with sulphuric acid solution to obtain basic scandium sulphate and then treated with oxalic acid. Obtained scandium oxalate precipitate is filtered and calcined to obtain scandium oxide.

EFFECT: high extraction of scandium.

7 cl, 4 tbl, 1 dwg, 21 ex