METHOD OF PRODUCING MAGNESIUM SULPHATE FROM MAGNESIUM-CONTAINING RAW MATERIAL Russian patent published in 2020 - IPC C01F5/40 C30B29/10 C22B3/08 C22B3/44 C22B3/22 

FIELD: metallurgy.

SUBSTANCE: invention relates to the technology of processing mineral raw materials and is intended for integrated use of metallurgical and mining wastes. Method of producing magnesium sulphate from magnesium-containing material involves preparation of initial material for leaching, leaching magnesium from raw material solution of sulphuric acid while heating with addition of washing water, filtering the obtained pulp with separating the magnesium sulphate solution from the insoluble cake with subsequent purification of the sulphuric acid solution from the impurities by neutralization and filtering the pulp to separate the ferriferous precipitate from the purified magnesium sulphate solution, evaporating and crystallising the purified magnesium sulphate solution, separation of magnesium sulphate crystals by filtration of the mother solution, wherein the magnesium-containing material used is serpentinite or magnesium-containing metallurgical dust, the leaching process is carried out with sulphuric acid with concentration of 300–500 g/l, and the magnesium sulphate solution neutralization is carried out with magnesium hydroxide with concentration of 200–300 g/l and the hydrogen peroxide addition to achieve pH = 7.0–7.5, wherein magnesium is extracted from produced ferruginous residue by means of acid repulping with sulphuric acid and separation of washed iron residue from flushing water, which is directed for leaching initial raw material.

EFFECT: technical result is obtaining magnesium sulphate heptahydrate and higher degree of magnesium extraction from initial raw material by optimizing parameters of main operations of method - leaching and purification of pulp from impurities, as well as additional extraction of magnesium from ferriferous sediment.

5 cl, 1 dwg, 7 tbl, 4 ex