GYPSUM BINDER MANUFACTURE METHOD Russian patent published in 2002 - IPC

FIELD: manufacture of building materials. SUBSTANCE: in a method of manufacturing gypsum binder comprising separate firing of gypsum raw to give gypsum cement and insoluble anhydrite and mixing of components, said gypsum cement is preliminarily stored under dry conditions during 1-3 months, after which it is screened for use into following fractions: 1.25 mm (28-37%), 0.20 mm (47-62%), 0.08 mm (1-25%), whereas insoluble anhydrite is screened for use into following fractions: 1.25 mm (7- 13%), 0.2 mm (35-38%), and 0.08 mm (52-55%), ratio of gypsum cement to insoluble anhydrite being (0.25-0.3): (0.70-0.75). Insoluble anhydrite can be activated in the course of grinding to give fraction 0.08 mm under conditions favoring formation of gas-dust plasma at mill rotor speed at least 1410 rpm. EFFECT: retarded hardening time and increased strength of gypsum stone. 2 cl, 4 tbl