METHOD OF PRODUCING CALCIUM SULPHIDE FROM PHOSPHOGYPSUM Russian patent published in 2020 - IPC C01B17/44 C01F11/08 C30B29/46 C30B29/64 C01G1/12 C09K11/55 C09K11/56 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing calcium sulphide from phosphogypsum and can be used in chemical industry, for example, in preparative inorganic synthesis and in production of semiconductor or luminescent materials. Method of producing samples of calcium sulphide is carried out by homogenisation of initial pre-dried at 100 °C of phosphogypsum and crystalline citric acid in ratio of phospho-gypsum : acid 3.0–4.0:1 in mixer with power of 0.45 kW at rate of 1,500 rpm, placing in alundum crucibles into working space of muffle furnace and heat treatment of produced charge at temperature of 700–900 °C for 1 h.

EFFECT: technical result consists in using a safe reducing agent – citric acid, reducing the duration of the process, simplifying the apparatus design while simultaneously obtaining materials with improved characteristics.

1 cl, 10 dwg, 1 tbl, 5 ex