METHOD FOR PROCESSING DOLOMITE Russian patent published in 1998 - IPC

FIELD: processing of mineral raw materials, preferably, low grade dolomite; production of magnesium oxide or its derivatives being used by producing fillers for paper, for producing plastics and mineral fertilizers. SUBSTANCE: dolomite is mixed with serpentinite or with sungulite till mass ratio of CaO is CaO = 1,87 SiO₂ + 0,35 Fe₂O₃ + 0,55 Al₂O₃,. Thus prepared mixture is briquetted and roasted within 0.75-1.25 h at 800-900 C. Product of heat treatment is alkalized by solution of magnesium chloride or magnesium sulfate or by sulfurous acid, ratio of solid and liquid phases being 1: 20-100. Precipitate is filtered, magnesium compound is isolated of filtrate. Solution being saturated with sulfur dioxide (which is residue of isolation of magnesium compound) is used as mentioned above solution of sulfurous acid. Content of impurities in desired product is not more than 0.85-2.5 mass %. EFFECT: increased degree of purification of desired product; decreased temperature of the process. 5 cl, 1 tbl