METHOD OF PRODUCING HIGHLY PURE α-ALUMINIUM OXIDE Russian patent published in 2012 - IPC C01F7/46 

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and can be used to produce highly pure alpha-aluminium oxide. Aluminium hydroxide, having average particle diameter equal to or less than 55 mcm, contains 0.11 wt % or less sodium, 6 ppm or less iron, 1.5 ppm or less calcium and 10 ppm or higher silicon, in terms of aluminium oxide. Said aluminium hydroxide is calcined at 1100-1500°C in a baking chamber, containing 85-93 wt % aluminium oxide and 7-14 wt % silicon oxide. The obtained alpha-aluminium oxide is washed. The highly pure alpha-aluminium oxide has silicon content of 20 ppm or less, iron - 10 ppm or less, calcium - 2 ppm or less, and sodium - 10 ppm or less.

EFFECT: invention enables to obtain a highly pure product.

8 cl, 5 dwg, 7 tbl