METHOD FOR COMPLEX PROCESSING OF SERPENTINITE

摘要

FIELD: chemistry.;SUBSTANCE: invention can be used to produce magnesium chloride, silica and red pigment. Serpentinite calcined at 680-750°C is treated with 4-8% hydrochloric acid solution with weight ratio of serpentinite to hydrochloric acid equal to 1:(15-40). The hot pulp is then decanted and filtered. The residue is dried to obtain silica, the filtrate is evaporated and silicic acid is separated. After separating silicic acid in form of sol-gel, hydrochloric acid is added to a solution containing magnesium and iron (III) chlorides until 4-8% hydrochloric acid solution is obtained. The obtained hydrochloric acid solution is used to treat a new portion of serpentinite. Further, the decantation, filtration, evaporation of filtrate, separation of silicic acid and treatment of the obtained solution with hydrochloric acid are repeated 3-5 times using new portions of calcined serpentinite. The solution concentrated that way at 90°C is mixed with serpentinite and filtered. Magnesium chloride is separated from the residue which contains iron (III) hydroxide. Said residue is treated at 350-400°C to obtain red pigment.;EFFECT: invention simplifies the processing serpentinite, improves environmental safety and reduces expenses and wastes.;1 dwg, 1 ex