METHOD FOR COMPLEX PROCESSING OF MAGNESIUM-CONTAINING RAW MATERIALS WITH OBTAINING PURE MAGNESIUM OXIDE Russian patent published in 2022 - IPC C01F5/02 C01B33/142 

FIELD: magnesium oxide production.

SUBSTANCE: invention relates to a technology for producing magnesium oxide from magnesium-containing mineral raw materials and is intended for the complex processing of magnesium ores and solid waste from the mining industry. Thermomechanical preparation of raw materials is carried out by its thermal activation at 500-600°C with mechanical activation in the form of grinding to d<0.1 mm. Decomposition is carried out with a solution of sulfuric acid 20-50%, after which the undecomposed precipitate is subjected to wet magnetic separation to separate amorphous silica from magnetic minerals of chromite and magnetite. Hydroxides of chromium-nickel-iron composition are separated from the magnesium-containing solution and magnesium is isolated from the magnesium-containing solution by selective oxalate precipitation in the region of pH 10.5-11 with preliminary precipitation of calcium oxalates in the region of pH 6-6.5 and annealing of the precipitate to magnesium oxide at temperatures 480-520°C.

EFFECT: method makes it possible to obtain zinc oxide not contaminated with calcium ions, to carry out waste-free processing of magnesium-containing raw materials with an increase in the degree of magnesium extraction.

1 cl, 1 ex, 2 dwg