METHOD FOR REPROCESSING ALIMUNA-CONTAINING CAKE Russian patent published in 1994 - IPC

FIELD: alumina production. SUBSTANCE: this method prescribes subjecting alumina-containing cake to agitational leaching with use of soda-alkali solution and strong wash water by wet grinding of cake and repulpational treatment of slime to produce pulp, separating pulp into aluminate solution and thickened slime, subjecting thickened slime to multiple countercurrent washing-out to produce strong wash water and wash slime, returning strong wash water to agitational leaching unit, forwarding washed slime to cement manufacturer, desiliconizing and decomposing aluminate solution to produce aluminum hydroxide, carbonate solution to be used for separating soda products, and preparing soda solution needed for agitational leaching. Wet grinding demands from 60 to 100 % soda-alkali solution. Volume ratio between rates of consumption of soda-alkali solution and strong wash water should be 1 : (0.2 to 1.2). Disclosed method further prescribes that remaining part of solutions be employed for repulpational treatment of slime. EFFECT: more advanced technique. 1 tbl