METHOD OF PREPARING ALUMINIUM OXIDE POWDER TO MANUFACTURE TRANSPARENT CERAMIC PRODUCTS Russian patent published in 1998 - IPC

FIELD: building industry, more particularly preparation of aluminium oxide powder. SUBSTANCE: aluminium oxide powder is prepared by liquid phase hydrolysis carried by mixing aluminium alkoxide with aqueous solution of one or more organic polymers, at least one of which is insoluble in alcohol resulting from hydrolysis. Said aqueous solution also contains sealing additive in dissolved form. The resulting mixture is stirred. Water to aluminium alkoxide molar ratio is from 2.5 to 5.0. Total amount of said organic polymers is 3- 30 wt % of equivalent content of aluminium oxide. Alcohol and water remnants are removed from the resulting hydrolysate till hydrolysate is converted to fragile state (xerogel). When removing alcohol and water remnants from hydrolysate, hydrolysate temperature should not exceed 200 C. The resulting aluminium hydroxide xerogel is ground to particle size of not greater than 50 mcm. Ground xerogel is heat treated in the air or in other oxidative medium at 1100-1350. EFFECT: increased specific efficiency of equipment and lower power consumption. 6 cl, 1 tbl