| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: magnesium-containing materials are subjected to decarbonising burning at temperature 720-780C in a weakly reducing atmosphere, oxygen potential of which is less than 385 kJ/mol O2. The burnt material is then cooled in a neutral atmosphere to temperature 100C, leached with mineral acid and filtered to remove precipitate from the obtained solution. The obtained filtrate is neutralised with sodium carbonate or sodium hydroxide in stages: at the first stage at pH 4-4.5 with addition of hydrogen peroxide for oxidation of iron (II) to iron (III) and its precipitation in form of Fe(OH)3, at the second stage - at pH 7.0-8.0, for precipitation of calcium and aluminium hydroxides. Magnesium precipitate is obtained from the filtrate at pH 12 in form of carbonate or hydroxide, which is taken for thermal processing, obtaining magnesium hydroxide. The magnesium-containing material used is wastes from rougher flotation in talc production, which are subjected to preliminary gravity concentration. ^ EFFECT: invention allows for comprehensive use of magnesium-containing materials. ^ 3 cl, 1 ex |
