FIELD: building materials industry, more particularly liquid glass based compositions for manufacture of heat- insulating materials. SUBSTANCE: raw mix comprises, wt.%: liquid glass, 82-89; microsilicon filler which is crystalline silicon production waste; 8.93-16.4; and sodium bicarbonate, 1.6-1.77. Method comprises preparing liquid glass mix, filler, sodium salt of inorganic acid, granulating the resulting mixture and subsequently heating it at 100 C for 1 h, and then at 250 C for 1 h. EFFECT: greater strength, lower heat treatment temperature, simpler technological process for manufacturing heat-insulating material. 3 cl, 2 tbl
