METHOD OF MAKING SCANDIUM OXIDE FROM RED SLAG Russian patent published in 2013 - IPC C22B59/00 C22B3/04 C22B3/20 C01F17/00 

FIELD: metallurgy.

SUBSTANCE: proposed method comprises multistep leaching of red slag by the mix of sodium carbonate and bicarbonate on forcing annealing furnace flue gases containing carbon dioxide there through to obtained solution. Then, three-step holding of said solution at increased temperatures is performed along with selective separation of precipitates after every said step. At first step, said solution is heated to temperature not exceeding 80°C for, at least, 1 hour. Thereafter, it is settled for, at least, two hours at natural cooling. At second step, said solution is boiled and mixed for, at least, two hours. At third step, said solution is evaporated to 50% of initial volume to add 46%-solution of sodium hydroxide to concentration of Na₂O_caustic of 1.5-2.0 kg/m³. Now, it is boiled for, at least, 2 hours and precipitate containing scandium oxide is settled for 10-16 hours at natural cooling.

EFFECT: simplified process, higher yield of scandium oxide.

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