METHOD FOR PRODUCING ULTRAFINE ACTIVATED ALPHA ALUMINA Russian patent published in 2023 - IPC C01F7/23 B22F9/04 B82Y40/00 

FIELD: chemical technology.

SUBSTANCE: method includes dry grinding of calcined alumina in a ball mill. To alumina before dry grinding, over the mass of raw materials, polyethylene glycol is added in an amount of 0.5% or polyethylene glycol simultaneously with polycarboxylate ether in an amount of 0.085-0.68%. As a feedstock, metallurgical alumina with a median particle size D₅₀ of 10-20 mcm is used, represented by a crystalline phase of γ-Al₂O₃, to which water is added until a pasty state is obtained, briquettes are prepared by laying in molds and dried to constant weight at a temperature of 110±15°C. The resulting briquettes are subjected to calcination at a temperature of 1250-1550°C for 1-3 hours, the baking products are crushed. Dry grinding is done in a ball mill for 0.5-8.5 hours.

EFFECT: obtaining particles with a primary crystal size from 0.2 to 1.1 mcm and a submicron fraction content from 65 to 87%, high fluidity of suspensions based on the obtained particles, as well as a high density of sintered samples at low baking temperatures.

1 cl, 1 dwg, 3 tbl, 4 ex