HEAT-INSULATION FORMULATION Russian patent published in 1997 - IPC

FIELD: insulation materials. SUBSTANCE: invention aims at developing formulation for low-density heat insulation operating at 1000 C and under mechanical loadings of the order of magnitude 5-7 MPa. Formulation contains liquid mineral glass as binder, 20-45% of hollow microspheres based on silicon-containing substance as refractory filler, and 3-11% alkali metal silicon- fluoride salt. Hollow microspheres comprise glass ones and microspheres in the form of smoke waste from burning coal, concentration of the latter being 80 wt % based on total amount microspheres. Size of microspheres ranges from 10 to 300 mcm. Formulation may additionally include 3-15% aluminum polyphosphate. Components are successively mixed to produce desired formulation, which is then poured into molds. Molding of samples is performed at 300-400 C, after which samples are removed from molds. Characteristics: heat stability up to 1000 C, mechanical strength 2-6 MPa, and apparent density 400-500 kg/cu.m. EFFECT: improved performance characteristics. 2 cl, 2 tbl