RAW MEAL FOR MANUFACTURING GYPSUM PRODUCTS AND METHOD OF PREPARATION THEREOF Russian patent published in 1997 - IPC

FIELD: manufacture of building materials. SUBSTANCE: raw meal for manufacturing wall and finishing materials contains, as binding agent, calcium sulfate $$-semihydrate, 33.5-75.0 wt %; as filler, sludge from chemical water treatment at heat power stations, 7.5-47.5 wt %; and, additionally, monosubstituted ammonium phosphate, 0.83-2.48 wt % (water to balance). Invention is distinguished with that the two first components in dry state are mixed on millstone for 1 min and then complemented with monosubstituted ammonium phosphate aqueous solution keeping agitating until pH of meal is changed from 4.5 to 7.0. EFFECT: improved performance characteristics. 2 cl, 2 tbl