METHOD FOR OBTAINING A SUBMICRON POWDER OF ALPHA-OXIDE OF ALUMINIUM Russian patent published in 2017 - IPC C01F7/44 B22F9/04 C04B35/10 

FIELD: chemistry.

SUBSTANCE: way of obtaining a submicron powder of alpha-aluminium oxide involves processing of aluminium hydroxide derived way Bayer in the mill with zatravochnymi particles, drying, calcination and disaggregation of the received powder by grinding in an organic solvent. As a dose, the alpha alumina nanopowder with particle sizes less than 25 nm in the amount of 1-5 masses % is used. The mixture of aluminium hydroxide with seed is treated by the dry grinding method in a ball mill with the addition of 20-30 wt % of hexane. Then, drying is carried out in air and calcination at 900-950°C in the airflow. Forced air flow over the calcined material has a temperature in the range of 500-950°C. Rate of temperature rise at calcination 300°C/hour.

EFFECT: invention makes it possible to obtain a powder consisting of alpha-alumina particles of spherical shape, weakly aggregated, with a narrow particle size distribution, suitable for obtaining a dense aluminium oxide ceramic with a reduction in energy costs.

3 cl, 1 dwg, 5 ex