METHOD FOR PRODUCING BINDING AGENT Russian patent published in 1998 - IPC

FIELD: production of building materials, more specifically, production of high-grade binding agent (binder) from high- calcium fly ash resulting from combustion of mineral fuel. SUBSTANCE: fly ash having high calcium content is recovered from filters at temperature about 700 C and subjected to rapid quenching down to temperature at least 100 C, followed by adding to fly ash active mineral additive (sandstone, polymictum variety having particularly high strength and hardness), gypsum bihydrate stone (in amount 3-5 wt. % of binder weight) and calcium chloride (in amount 1-3 wt.%). Resulting mixture is subjected to grinding to achieve grinding fineness 550-600 sq. m/kg. EFFECT: binder produced by proposed method has initial activity (strength) 25,3 MPa after 28 days of hardening in normal humid air atmosphere; when subjected to heat treatment in high- humidity atmosphere using process procedure (3+8+3) and after subsequent 28 days of hardening, strength increases up to 39,7 MPa; binder is highly reliable and immune to non-uniform volume variations.