ALUMINIUM OXIDE, LUMONOPHORES AND MIXED COMPOUNDS AND RESPECTIVE METHODS OF PREPARATION Russian patent published in 2015 - IPC C01F7/30 C09K11/80 C09K11/02 

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic chemistry and can be used in obtaining luminophores for coatings of fluorescent lamps. Gamma aluminium oxide, obtained from alumen, in an amount of 85 wt % - 95 wt % is mixed with 0.4 wt % - 1.8 wt % of a sintering agent - NH₄F and 2.5 wt % - 13 wt % of alpha aluminium oxide nuclei. The mixture is annealed in a furnace at a temperature from 1150°C to 1400°C for 1-6 hours, crushed for 16 hours in a ball mill with milling aluminium oxide balls, the number of which is at least by 20 times greater than the amount of the annealed mixture. The diameter of the milling aluminium oxide balls is from 3 cm to 5 cm. The crushed mixture is sieved through a net, made from a non-polluting material, with a cell size from 150 mcm to 250 mcm.

EFFECT: obtained alpha aluminium oxide consists mainly of particles with d₅₀ size from 0,3 mcm to 2 mcm mainly of a spherical shape, which makes it possible to optimise the emitting properties of a fluorescent layer.

6 cl, 4 dwg, 7 ex