METHOD FOR PRODUCING CALCIUM HYDROSULFIDE Russian patent published in 2021 - IPC C01F11/00 C01G1/12 

FIELD: chemical industry.

SUBSTANCE: invention relates to the production of calcium hydrosulfide and can be used in the flotation of copper-, zinc-, lead-containing ores, in the purification of technological solutions and wastewater and in the leather industry. The method for producing calcium hydrosulfide includes preliminary production of hydrogen sulfide by processing raw materials containing zinc sulfide with a size of 50-74 microns, sulfuric acid with a concentration of 55-70 wt% at a molar ratio of zinc sulfide to sulfuric acid equal to 1.0: (1.01.1), and heating the zinc sulfide pulp in the temperature range from 130 to 160C with a mass ratio of liquid sulfuric acid to solid zinc sulfide in the pulp equal to 35. Then hydrogen sulfide is separated from droplets of sulfuric acid and brought into contact with an aqueous suspension of calcium oxide with a molar ratio of hydrogen sulfide to calcium oxide equal to 2:1.

EFFECT: invention constitutes an economical technology of production of calcium hydrosulfate from the most accessible, cheap feedstock widely used in industry.

1 cl, 3 dwg, 5 tbl, 4 ex