FIELD: technological processes.
SUBSTANCE: invention may be used in chemical industry. At the first stage of method of composition preparation in vessel at first part of sodium silicate is introduced in the form of solution that has concentration in translation to SiO2 below 15 g/l, then solution of sulfuric acid is added until at least 60% of Na2O amount that is available in vessel is neutralised. At the second stage simultaneously solution of sulfuric acid and sodium silicate are added, additional amount of sulfuric acid is added until pH reaction mixture is obtained between 3 and 6.5, and mixture is conditioned at mixing for 1-5-30 minutes. Precipitate is flushed from Na2SO4. Precipitate is thinned with mechanical action, and also by addition of sodium aluminate until ratio of Al mass to SiO2 mass of 0.0027 ÷ 0.0030 is obtained. Sulfuric acid solution is added until pH value is 6.3 ÷ 6.7. Moist precipitate is heated up to 30 ÷ 70°C and activated by passing through magnetising device with magnetic field intensity of 250 ÷ 450 kA/m, for at least 0.3 seconds. After activation, not later than after 0.5 hours, powder is dried. Suggested invention permits to prepare composition that contains compounds of deposited silicon dioxide and aluminium, which has specific surface CTAB SCTAB 140÷240 m2/g, factor of deagglomeration by ultrasound Fd more than 11 ml, average diameter after deagglomeration with ultrasound below 2.5 mcm, which possesses property of reduced dusting.
EFFECT: allows to prepare composition that possesses property of reduced dusting.
4 cl, 2 ex
