HIGH-STRENGTH GYPSUM PRODUCTION METHOD Russian patent published in 2006 - IPC C04B11/02 

FIELD: binding material, particularly high-strength gypsum production.

SUBSTANCE: method involves hydrothermally treating natural dehydrate gypsum rock with saturated steam under 1.3 kg/cm² pressure; drying thereof under atmospheric pressure. Above treatment is performed at 100-130°C temperature for 7 hours. Then the gypsum material is subjected to evaporation under excessive pressure of 0.2-1 kg/cm² along with uniform temperature reduction up to 95-96°C temperature obtaining. Then the material is dried and cooled for 5.5 hours under atmospheric pressure to reduce gypsum temperature up to 45°C. The treated material is crushed and grinded to obtain gypsum particles having 0.2 mm dimensions, wherein not more than 0.2% of gypsum particles remain on sieve having 0.2 mm openings.

EFFECT: increased gypsum quality due to provision of uniform regular gypsum structure by uniform cooling of gypsum subjected to hydrothermal treatment.

1 tbl, 2 cl