LOW-CARBON ALKALI-ACTIVATED CEMENT Russian patent published in 2024 - IPC C04B7/153 C04B18/04 C04B18/08 C04B18/24 

FIELD: construction materials.

SUBSTANCE: invention relates to alkaline and alkaline-earth hydraulic binders and is intended for preparing concrete and mortar in prefabricated and monolithic construction, as well as for repair and restoration works. Low-carbon alkali-activated cement includes flue dust from a gas cleaning system of an air medium of a cupola with a specific surface of 700–800 m²/kg and an alkaline activator, wherein said flue dust is mechanically activated to a specific surface area of 700–800 m²/kg together with dry sodium hydroxide, taken in an amount to achieve the required concentration in the two-component alkaline activator, wherein the cement additionally contains a stabilizing active mineral additive from a fine mixture consisting of flue ash and ash residue formed during combustion of buckwheat husks in a vortex furnace, containing in the mixture a total amount of calcium oxide and magnesium of not less than 30 wt.% with an average particle size of not more than 40 mcm with specific surface area of 1,000 m²/kg and more, and as the liquid part of the alkaline activator, it contains an aqueous solution of sodium silicate with density at temperature of 20°C of not less than 1.36–1.5 g/cm³ with a weight fraction of sodium oxide of 8.1–13.3 % with a silicate modulus of 2.7–3.3, taken in ratio 1:1.2–1:1.43 or to achieve total equivalent of Na₂O from 12 to 17%, with the following ratio, wt.%: flue dust from gas cleaning system 74–82, caustic soda 6–14, mixture of flue ash and ash residue from combustion in vortex furnace of buckwheat husks 12 %, aqueous solution of sodium silicate in excess of 100% to W/T 0.45–0.6.

EFFECT: obtaining alkaline and alkaline-earth hydraulic binders, having a low carbon footprint, aiming at reduction of process conversions, as well as promoting recycling of industrial and agricultural wastes without deterioration of mechanical characteristics.

1 cl, 4 tbl