METHOD FOR PREPARATION OF ALUMINUM HYDROXIDE Russian patent published in 2021 - IPC C01F7/44 C01F7/02 B01J20/08 B01J21/04 B01J23/10 B01J32/00 B01J35/10 B01J37/02 

FIELD: chemical industry.

SUBSTANCE: invention can be used in the production of aluminum oxide adsorbents, desiccants, catalyst carriers and catalysts. To prepare aluminum hydroxide containing isolated lanthanum atoms, the product of rapid heat treatment of hydrargillite is crushed to particles with a volumetric average diameter of 5-25 microns, then hydrated by 0.3wt. %, nitric acid solution, filtered and washed from impurity sodium. The wet sediment is subjected to hydrothermal treatment in the form of a suspension in an aqueous solution of nitric acid and a lanthanum source. After drying, aluminum hydroxide is obtained with the general formula Al₂O₃⋅nH₂O, where n = 1.5-1.9, consisting of pseudoboehmite and a disordered χ-like phase of aluminum oxide at a ratio of these phases, wt.%: 60-95 pseudoboehmite, 5-40 disordered χ-like phase of aluminum oxide. Aluminum hydroxide contains isolated La atoms on its surface with a surface density of 2-50 atoms per 10 nm² surface and a ratio of Al atoms to La atoms equal to 50-10000, includes constitutional water, contains impurity Na in the range of 0.001-0.04 wt. %. The specific surface area after calcination at 550°C is 200-300 m²/g, the average pore diameter is 8-15 nm, the pore volume is 0.45-0.75 cm³/g.

EFFECT: invention makes it possible to increase the catalytic activity and selectivity of aluminum hydroxide, reduce the cost of obtaining it.

7 cl, 1 tbl, 7 ex