METHOD OF CONVERTING SOLUTION OF ALUMINIUM SALTS OF CARBOXYLIC ACIDS TO ALUMINA AND CARBOXYLIC ACIDS Russian patent published in 2010 - IPC C01F7/20 C01F7/36 

FIELD: chemistry.

SUBSTANCE: method has three versions. In the first version, an aqueous solution of aluminium, alkali and alkali-earth metal salts of carboxylic acids is neutralised with basic agents to obtain a suspension containing an aqueous solution of alkali and alkali-earth metal salts of carboxylic acids and a precipitate having formula Al(OH)_xAc_y, where Ac is an anionic carboxylic acid residue, x=0.1-3.0, y=2.9-0.0. The obtained precipitate is separated from the aqueous solution. In the second version, an aqueous solution of aluminium, alkali and alkali-earth metal salts of carboxylic acids is evaporated to obtain a suspension containing an aqueous solution of alkali and alkali-earth metal salts of carboxylic acids and a precipitate having formula Al(OH)_xAc_y, where Ac is a carboxylic acid residue, x=0.1-1.5, y=2.9-1.5. The obtained precipitate is separated from the aqueous solution. In the third version, an aqueous solution of aluminium salts of carboxylic acids is evaporated to form a suspension containing a precipitate of formula Al(OH)_xAc_y, where Ac is a carboxylic acid residue, x=0.1-1.5, y=2.9-1.5. The obtained suspension is neutralised with basic agents to form a suspension containing an aqueous solution of alkali and alkali-earth metal salts of carboxylic acids and a precipitate of formula Al(OH)_xAc_y, where Ac is an anionic carboxylic acid residue, x=0.1-3.0, y=2.9-0.0. The precipitate is separated from the aqueous solution. The precipitate obtained in the first, second and third versions undergoes thermal treatment to obtain aluminium hydroxide and a free carboxylic acid and/or its anhydride and/or a mixture of carboxylic acids and/or their anhydrides, which are returned to the step for dissolving aluminosilicate material, and the obtained aluminium hydroxide is calcined to obtain alumina.

EFFECT: invention reduces corrosion aggressiveness of medium, minimises consumption of carboxylic acid owing to its recuperation.

17 cl, 8 ex