METHOD FOR PROCESSING OF ALKALINE ALUMINOSILICATE RAW MATERIALS Russian patent published in 1996 - IPC

FIELD: production of alumina. SUBSTANCE: method involves preparing charge by mixing of alkaline aluminosilicate raw materials with limestone, waste slime and with compounds of alkali metals, grinding thus obtained charge and its adjustment. Said adjustment is carried out till molar ratio of CaO and SiO₂ and R₂O/Al₂O₃ are 1.9-2.1 and more than 1 or equal to it respectively. R₂O represents total amount of Na₂O and K₂O as calculated for Na₂O.. Thus obtained charge is affected by caking. Said cake is extracted with waste soda alkaline solution. Thus prepared aluminate solution is separated from belite residue. Said belite residue is washed with water and is then used in cement production. Mentioned above aluminate solution is affected by desilication. Thus obtained white residue is fed for production of charge, and said aluminate solution is affected by carbonization. The latter process is carried out with the help of gases being prepared during caking of charge. Soda product are isolated of solution being prepared during carbonization. Charge is ground till content of 80 μm fraction is 500-800 % of value of molar ratio Fe₂O₃/SiO₂ in raw materials. Molar ratio of R₂O/Al₂O₃ in said charge is maintained within ranges 0.003-0.06 of molar ratio of SiO₂/Al₂O₃. Concentration of aluminium oxide in aluminate solution during extraction is maintained within 150-350 of molar ratio of Al₂O₃/SiO₂ in said cake. EFFECT: improves efficiency of method. 1 tbl