METHOD FOR PRODUCTION OF ALUMINIUM Russian patent published in 1999 - IPC

FIELD: production of aluminium by electrolytic separation of it from aqueous solutions simultaneously with hydrogen. SUBSTANCE: use is made in the method of a pool cathode, for example gallic one. The content of aluminium in metal is increased up to 6 mass percent, the alloy is withdrawn from electrolyzer, cooled within 98 to 26 C, aluminium is separated by crystallization, and primary saturated solid solution with a content of aluminium of about 80 mass percent composition is returned to electrolysis as cathode metal, and primary solid solution is melted and subjected to recrystallization at a temperature of below 660 C, separating in succession the secondary, tertiary, etc, solid solutions from liquid until aluminium of commercial purity is obtained from them. The residual quantities of gallium are removed by isothermal holding of metal in a furnace at a temperature of 660 C, draining off the surface aluminium layer, and separately the bottom layer, enriched by gallium. EFFECT: prevented processes of passivation of the cathode surface, electrolysis is accomplished easily with guaranteed separation of aluminium to cathode alloy. 6 cl, 2 dwg, 4 tbl