METHOD OF EXTRACTING SCANDIUM FROM RED MUD FROM ALUMINA PRODUCTION Russian patent published in 2019 - IPC C22B59/00 C22B3/12 C22B3/24 

FIELD: chemistry.

SUBSTANCE: invention relates to extraction of scandium from red mud - alumina production wastes. Extraction of scandium includes steps of redispoloration of red mud, sorption stepwise leaching of scandium from pulp using an ion-exchange sorbent to obtain scanned saturated ionite and pulp-depleted pulp, desorption of scandium with solution of sodium carbonate to obtain desorbed ionite, which is repeatedly sent to sorption leaching of scandium, and solution of commercial reclaimed scandium, which is directed to obtain scandium concentrate. Repulping red sludge is carried out with a solution of a mixture of carbonate and sodium bicarbonate with concentration of Na₂O_total 40–80 g/dm³, wherein Na₂O_bicarb content makes from 50 to 100 % of Na₂O_total. Sorption leaching of scandium from pulp of red mud is carried out stepwise on phosphorus-containing ionite continuously in counterflow mode with direct contact of "pulp-ionite" at temperature of 40–90 °C. At that, leaching of scandium at each stage is carried out at mass ratio of solid and liquid phases in pulp of red mud T: L = 1:2.5–5.0. Desorption of scandium from organic phase of ionite is carried out with sodium carbonate solution with Na₂CO₃ concentration 200–450 g/dm³ to obtain commodity recyclate of scandium, from which scandium concentrate is extracted.

EFFECT: method increases degree of extraction of scandium from red mud with improvement of quality of commodity reclamation of scandium at reduction of expenses for method implementation.

7 cl, 1 dwg, 7 tbl, 2 ex