METHOD FOR PRODUCING ALUMINUM OXIDE DISPERSED AT pH GREATER THAN 8 Russian patent published in 2021 - IPC C01F7/02 C01F7/44 C09C1/40 

FIELD: aluminum production.

SUBSTANCE: invention relates to a technology for producing highly dispersed aluminum oxide. The method for its production includes following steps: i) obtaining aluminum oxide suspension; ii) aging of aluminum oxide suspensions to obtain aged aluminum oxide suspension containing aluminum oxide with crystallite size of 38-450 (Plane 120), while aluminum oxide suspension is aged by holding at temperature of 95-220°C for a period of 30 minutes to 8 hours; iii) adding tricarboxylic acid to aged slurry of aluminum oxide to obtain acid-modified suspension; iv) aging of acid-modified suspension at temperature of 75°C до 125°C to produce the target suspension; and v) spray drying of the target suspension, the method being characterized by addition of dicarboxylic acid, either at Step iii) of the method together with tricarboxylic acid, or by adding dicarboxylic acids in the target suspension after stage iv) before spray drying stage v). The resulting aluminum oxide is dispersed at a pH greater than 9.5 by more than 95% and has viscosity lower than 0.4 Pa·s at 10 wt % on solid basis.

EFFECT: technology makes it possible to obtain highly dispersed aluminum oxide for aluminum production.

14 cl, 1 tbl, 5 ex, 1 dwg