METHOD OF PREPARING MAGNESIUM OXIDE FORM SERPENTINOUS ULTRABASIC ROCK Russian patent published in 2000 - IPC

FIELD: chemical industry. SUBSTANCE: serpentinous ultrabasic rock comprising wt %: SiO₂, 36; MgO, 34; FeO, Fe₂O₃ manganese, titanium, nickel, chromium oxides, 6; water, 13 and impurities, the balance, is dissolved in H₂SO₄. 1 hour later H₂O₂ is added, and mixture is cooled to +5C under stirring. Stirring rate is 30-300 rpm. Stirring gives crystals. Crystallized mixture is poured with water, precipitate is separated by filtration. 8 % alkali is added to MgSO₄ filtrate solution and sulfates of admixed metals. Deposit of compounds of admixed metals is precipitated and filtered. Pure MgSO₄ solution filtrate is fed into spraying drier. Temperature of gas and air mixture is 200-600 C and air to gas ratio is 1:10. The resulting anhydrous MgSO₄ is decomposed at 1100-1200 C for 20-30 min, washed, and precipitate is separated. Desired MgO product comprises, wt %: MgO, at least 99; Fe₂O₃, 0.21; and H₂O, the balance. Method is simple and economical. EFFECT: more efficient preparation method. 3 ex