METHOD FOR PROCESSING SYNNYRITE Russian patent published in 2021 - IPC C22B1/16 C22B3/08 C01F5/40 C01F7/26 C01D5/02 

FIELD: chemical industry.

SUBSTANCE: invention relates to the chemical processing of high-potassium aluminosilicate synnyrite to produce aluminum oxide, potassium and magnesium sulfates. The processing of synnyrite includes the preparation of raw materials, sintering it with an alkaline earth additive, sulfuric acid leaching, followed by dilution and filtration of the silicon-containing residue with the separation of a solution of sulfates, evaporation of a solution of sulfates and crystallization of alum. After that, the resulting suspension is filtered to obtain a crystalline product and a solution of magnesium sulfate. During sintering, which is carried out at a temperature of 1050-1200°C, magnesium-containing additives are used as an alkaline earth additive for 1-4 hours at a ratio of synnyrite : additive equal to 1:(0.25-1.25). Sulfuric acid leaching is carried out at a concentration of the initial sulfuric acid of 30-50%, at a temperature of 90-100°C, for 30-60 minutes and a ratio of S:L=1: (3-5) with further dilution to S:L=1: (6-8).

EFFECT: method makes it possible to isolate aluminum-potassium alum suitable for further production of alumina and/or aluminum-magnesium spinel and potassium magnesia using dolomite, magnesite or brucite as a magnesium-containing additive during sintering with synnyrite, with an increased degree of alum extraction.

4 cl, 1 dwg, 11 tbl, 3 ex