METHOD OF PROCESSING FRESH PHOSPHOGYPSUM Russian patent published in 2020 - IPC C04B11/26 C04B28/14 

FIELD: chemistry.

SUBSTANCE: present invention relates to chemical industry, specifically to processing wastes from chemical and metallurgical industries, in particular to the technology of recycling phosphogypsum, and can be used to produce a phosphogypsum processing product used as raw material, a material, an article or a semi-product in various industries, for example, as base or additive in composite and nano-compositions used in transport, industrial and civil construction industries. In the method for low-temperature treatment of fresh phosphogypsum, a fresh phosphogypsum hemihydrate with temperature of 37–40 °C on the conveyor layer with thickness of 1 to 30 cm is fed into a continuous cooling chamber, where low-temperature treatment is carried out with steam-air mixture with operating temperature of 0–20 °C and relative humidity of mixture of 50–95 % for one or two hours with subsequent loading of hemihydrate cooled to temperature of 20 °C of phosphogypsum into vapor-permeable container. Steam-air mixture can additionally be fed with carbon dioxide.

EFFECT: task of the technical solution is simplification, cheapening and minimization of power inputs of the process of processing fresh phosphogypsum by increasing duration of storage and transportation of fresh phosphogypsum in the state of phosphate hemihydrate of calcium sulphate with preservation of its binding properties.

1 cl, 3 dwg, 4 tbl