METHOD OF PRODUCING HEAT-INSULATING MATERIAL Russian patent published in 2020 - IPC C04B20/04 C04B28/26 C04B40/02 C04B111/20 

FIELD: chemistry; construction.

SUBSTANCE: invention relates to production of construction materials, particularly those relating to production of porous heat-insulating articles, and can be used in production of heat-insulating material, especially light concrete, as well as heat-insulating fillings and heat-resistant insulation of heat apparatus. In the method of producing a heat-insulating material based on liquid glass, involving thorough mixing, milling and heat treatment of the components of the composition, additionally used as a fly ash component, lime-dust of lime produced during calcining of limestone, and waste solution of iron etching with sulphuric acid at the following ratio of components, wt. %: liquid sodium glass 25–30, flue ash 42–44, lime-dust lime 9–12, waste solution of iron etching with sulphuric acid 18–20, wherein milling, mixing and heat treatment of components is carried out in three stages: at the first stage in the bead mill, mixing liquid sodium glass and fly ash to particle size of 1–3 mm, heating to temperature of 150–160 °C for 6 hours, obtained suspension of sodium aluminosilicate is transferred to two-roller high-speed mixer; at the second stage in a reactor with a high-speed stirrer, neutralization of the spent solution of iron etching with sulphuric acid by lime-dust dust is performed to pH = 8.5–9.0 at temperature of 80–90 °C and a suspension of calcium sulphate and iron hydroxide is obtained, then flue ash is added and neutralization of said suspension is performed to pH = 6.5–7.0 and a suspension containing a mixture of gypsum and calcium aluminate is obtained, which is fed into a high-speed two-roller mixer, in which it is mixed with a suspension of sodium aluminosilicate, in a third stage the resulting slurry from the high-speed two-roll mixer spray fed to the fluidized bed furnace, in which it is heat treated flue products with an excess of oxygen at temperature of 140–350 °C and obtaining heat-insulating material with particle size of 0.6–1.0 mm, including expanded sodium aluminosilicate, expanding cement - product of interaction of calcium aluminosilicate with gypsum and iron oxide pigments of yellow colour at temperature of 140 °C and red colour at temperature of 350 °C.

EFFECT: technical result is high strength, possibility of producing heat-insulating materials of yellow or red colours, recycling wastes from production.

1 cl, 1 dwg, 1 tbl, 2 ex