FIELD: process engineering.
SUBSTANCE: invention relates to nonferrous metallurgy. Alumina-bearing stock is leached to obtain aluminate solution to be separated from red mud and directed to crystallisation to produce mother solution and precipitate containing aluminium hydroxide. Aluminium hydroxide is subjected to calcination for production of alumina. Crystallisation is performed at 25-39°C by adding
aluminium sulphate to aluminate solution in amount of 3.8-10.2 wt % of aluminium oxide content in aluminate solution.
EFFECT: higher yield, accelerated process, ruled out aluminium hydroxide seeding.