POWDERED ALPHA-ALUMINIUM OXIDE, METHOD OF PREPARING SAID OXIDE AND OBJECTS THEREFROM Russian patent published in 2010 - IPC C01F7/44 

FIELD: chemistry.

SUBSTANCE: powdered alpha-aluminium oxide consists of rounded particles with size ranging from 40 to 250 micrometres, having specific surface area of not less than 100 m²/g, mainly in the range of 120-180 m²/g, kept at temperature ranging from 700°C to 1400°C. The surface of the particles is polycrystalline. The method of preparing powdered alpha-aluminium oxide involves addition of hydrated aluminium oxide particles with size ranging from 40 to 250 micrometres, containing from 10 to 30% chemically combined water, into a high-temperature gas stream in which powder particles are heated to temperature not below 700°C and not above 2000°C. The process is carried out in a single step. The product is obtained by mixing powdered alpha-aluminium oxide with an organic polymer gel, filling a mould with the obtained mixture, heating the mould to at least 700°C but not above 1500°C, sintering in a single step until complete evaporation and burn-out of the organic polymer gel and strong coalescence of particles of the initial powdered alpha-aluminium oxide.

EFFECT: invention enables use of powdered alpha-aluminium oxide in extreme temperature conditions, its preparation in a single step and making objects of different sizes and shapes.

4 cl, 10 dwg, 4 tbl