METHOD OF PRODUCTION OF ALUMINUM OXIDE Russian patent published in 2005 - IPC

FIELD: hydrometallurgy; production of aluminum oxide.

SUBSTANCE: the invention is pertaining to the field of hydrometallurgy of aluminum compounds and bauxites and may be used for production of aluminum oxide at processing of the bauxites containing alumina. The method of production of aluminum oxide provides for a settling of aluminum hydroxide from a solution of sodium aluminate, its drying and calcination. At that sodium aluminate is produced from aluminum-containing raw material in the capacity of which use a by-product of etching of an aluminum band in production of aluminum constructions. Aluminum-containing raw material is treated at the temperature of 70°C with 3-7 % solution of a sodium hydroxide in amount of 100, 125 or 150 cm³ within 3-5 hours. Produced sediment is filtered out and fed to retreatment with sodium hydroxide, and the filtrate containing sodium aluminate is mixed with about 1-2 M solution of sulfuric acid till obtaining pH = 6.4-7.4, the produced sediment of aluminum hydroxide is filtered out and flushed by water to remove sodium ions, then the produced aluminum hydroxide is heated up in a drying cabinet up to the temperature of 200°C at the rate of heating of 10-20°C /hour and annealed in the muffle furnace within 9 hours up to the temperature of 650°C at the speed of heating of 50°C /hour. The offered method of production of aluminum oxide allows: to reduce the net cost of aluminum hydroxide, to utilize a by-product of etching of an aluminum band in production of aluminum constructions.

EFFECT: the invention allows to reduce the net cost of aluminum hydroxide, to utilize a by-product of etching of an aluminum band in production of aluminum constructions.

1 tbl, 15 ex