METHOD OF PRODUCING A SMALL-CRYSTALLINE ALUMINATE OF MAGNESIUM Russian patent published in 2017 - IPC C30B29/26 C01F7/16 C04B35/443 C04B35/626 B01J3/00 

FIELD: chemistry.

SUBSTANCE: method comprises the autoclaving of the initial mixture of water in the autoclave, comprising a molar ratio of 1.0-1.2 oxyhydroxide or aluminium hydroxide with magnesium oxide and an activating additive, which uses an aqueous solution of glycerol (C₃H₅(OH)₃) and aluminium chloride⋅ AlCl₃⋅6H₂O. The treatment is carried out first under subcritical conditions, at a temperature of 200 to 360°C and steam pressure from 1.5 to 19 MPa for 6-20 hours, and then under supercritical conditions, water vapor at a temperature of 370 to 420°C and steam pressure from 21.5 to 30.4 MPa for 1-12 hours, after which the water vapor is removed, the autoclave is cooled to room temperature, the magnesium aluminate obtained is discharged, washed with distilled water until a pH of 7 washing waters is obtained and dried at temperature up to 70°C to constant weight, while glycerin is taken in an amount of 1-12 wt %, and aluminium chloride in an amount of 0.01-0.8 wt % relative to the weight of the final product, magnesium aluminate, the weight ratio of aluminium chloride to glycerol being 0.01-0.1. A mixture of magnesium oxide powders and hydroxide or aluminium oxyhydroxide can be preliminarily sifted or processed in a planetary or ball mill to form a homogeneous mass.

EFFECT: invention makes it possible to obtain a single-phase fine-crystalline magnesium aluminate with an average crystal size of 0,2-0,5 mcm and a content of the main substance of not less than 99,99 percent.

2 cl, 1 dwg, 1 tbl, 6 ex