METHOD OF PREPARING LIQUID GLASS BY HYDROTHERMAL METHOD Russian patent published in 1999 - IPC

FIELD: building materials industry, more particularly manufacture of silicate building materials, porous heat- and sound-insulating materials adhesive hardenable compositions, absorbents, and various industries which use sodium silicate solutions. SUBSTANCE: silica- containing component with specific area of 1000-7000 sg/g (grain size of less than 0.3 mm) is mixed at SiO₂/N₂O molar ratio of 2-3.5 with second component (34-36 wt %) using aqueous sodium hydroxide solution and the resulting mixture is admitted into stirred autoclave or rotary autoclave in which said mixture is subjected to hydrothermal treatment at 170-190 C (saturated steam pressure at given temperatures varies from 0.8 to 1.2 MPa) for 30-60 minutes. The resulting product under residual pressure is forced out of autoclave and is mixed with water having temperature from 40 C to 90 C to attain final product, e.g. liquid glass. Two-stage preparation method is actually realizable method of hydrothermal synthesis of final product with wide range of properties at extremely low reaction parameters such as pressure, temperature and time, from comparatively coarsely dispersive natural or industrial stock which requires no preliminary activation. EFFECT: more efficient preparation method. 1 ex, 1 tbl