METHOD OF PRODUCTION OF HIGH-MODULUS WATER GLASS Russian patent published in 1999 - IPC

FIELD: technology of production of high-modulus water glass for manufacture of building materials; applicable in manufacture of heat- insulating and other articles. SUBSTANCE: method includes preparation of suspension from silica-containing amorphous substances in solution of sodium hydroxide and subsequent hydrothermal treatment. Silicon- containing amorphous material is used in form of wastes of production of crystalline silicon - microsilica containing 83-93 wt.% of SiO₂ and 6-16 wt wt.% of carbonaceous impurities (graphite and carborundum). Suspension is prepared from microsilica and sodium hydroxide with solid-liquid phases ratio of 1:(1.66-1.92) and concentration of Na₂O in solution of 52.1-69.3 kg/cu.m. Hydrothermal treatment of suspension is carried out at 95-98 C and atmospheric pressure for 15-30 min. EFFECT: reduced consumption of alkali and process duration, simplified technology. 3 tbl