METHOD FOR PRODUCING ALPHA-ALUMINIUM OXIDE OF HIGH PURITY Russian patent published in 2017 - IPC C25B1/00 C01F7/02 C01F7/42 

FIELD: chemistry.

SUBSTANCE: method includes anodic dissolution of high purity aluminium in an aqueous solution of ammonium nitrate, refining the electrolyte by removing 50-100% of the first batch of aluminium hydroxide with preliminarily settling in the electrolyte for 12-24 hours, separating subsequent batches of aluminium hydroxide and electrolyte, washing the subsequent batches of aluminium hydroxide with distilled water and their thermal treatment, which is carried out by pre-drying for 12-24 hours at a temperature of 200-250°C and final calcination for 15-18 hours at a temperature of not less than 1100°C, stirring of the product is carried out every 3 hours during calcination.

EFFECT: invention allows to obtain alpha-aluminium oxide with a high content of the main component and with an average dispersion of 40-45 mcm.

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