FIELD: production of gypsum products.
SUBSTANCE: invention can be used in ceramic industry for manufacturing porous moulds. Method for making gypsum moulds for casting ceramic products includes preparing a mould set. A gypsum mortar is prepared by pouring water and pouring gypsum into a mixer. The mixture is exposed and mixed, the gypsum mortar is poured into the mould set, the material is exposed, the mould set is dismantled, and the mould is dried. At the same time, when preparing a gypsum mortar, gypsum based on α-calcium sulphate hemihydrate is used. The water temperature is 10-20°C. The water-gypsum ratio is 0.75-0.90. The gypsum is filled out for 1.0-2.5 minutes, the exposure of the mixture to saturate the gypsum particles with water is carried out for 1.0-2.0 minutes, mixing is carried out for 2.0-5.0 minutes.
EFFECT: increase of service life of large plaster moulds for manufacturing of ceramic products.
1 cl, 4 tbl, 12 ex
