METHOD OF PROCESSING MAGNESITE DOLOMITE RAW MATERIAL Russian patent published in 2014 - IPC C22B3/06 C22B26/22 

FIELD: chemistry.

SUBSTANCE: invention relates to the mining and processing industry and can be used in utilisation of wastes of magnesite ore mining and benefication. A method of a magnesite dolomite raw material processing includes raw material crushing, classification and further leaching of magnesium by an acid. Particles with coarseness of 0.2-4.0 mm are separated from the magnesite dolomite raw material. Leaching is carried out at a temperature of 15-20°C by 10-50% water solution of nitric acid with stoichiometric composition: dolomite from 1.1:1 to 1.3:1 with dolomite dissolution. A magnesite sediment is separated from the obtained solution, containing magnesium and calcium ions, by filtration, sulfuric acid is added into a solution with precipitation of calcium in the form of gypsum and obtaining nitric acid as a result of reaction Ca(NO₃)₂+H₂SO₄+2H₂O→CaSO₄·2H₂O↓+2HNO₃. Gypsum is separated by filtration, the solution is blown with carbon dioxide, the sediment of magnesium hydrocarbonates is obtained and separated by filtration. The obtained solution of nitric acid is conditioned to the required concentration and supplied to leaching.

EFFECT: invention ensures higher extraction of magnesium from the magnesite dolomite raw material.

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