METHOD OF DEEP ALUMINATE SOLUTIONS DESILICONISATION Russian patent published in 2015 - IPC C01F7/16 

FIELD: metallurgy.

SUBSTANCE: invention relates to alumina production, in particular aluminate solutions desiliconisation during alumina production out of high-silicon aluminium raw material. Method of deep aluminate solutions desiliconisation means lime treatment by aluminate-alkali solution with production of alumo-calcic element, two-stage desiliconisation of aluminate-alkali solutions with use of the produced alumo-calcic element as intensifying additive, concentration and filtration of desiliconisation products, clearing of desiliconised solution, according to the invention sludge of the second stage of desiliconisation is injected to the cleared aluminate solution after the first stage of desiliconisation, exposition of the produced pulp is performed for 30 minutes, and then to the pulp the alumo-calcic element is added by two successive portions with interval 30 minutes in amount 50% of total need of the injected chemical.

EFFECT: invention reduces consumption of alumo-calcic element to 1,7÷2,6 g/l of CaO_act in its composition to achieve practically complete separation of Al(III) and Si(IV) ions in strong electrolyte, produces alumina of high makes "Г"-00 and "Г"-000, and increases technical and economic parameters of the alumina production out of high-silicon raw material.

2 dwg, 12 ex