METHOD OF PRODUCTION OF HYDRAULIC BINDER Russian patent published in 2003 - IPC

FIELD: manufacture of building materials; production of hydraulic binders. SUBSTANCE: proposed method includes preparation of raw material mixture containing silica oxide SiO₂, calcium oxide CaO, magnesium oxide MgO, aluminum oxide Al₂O₃, ferrous iron FeO and ferric iron Fe₂O₃ followed by heat treatment and grinding of product thus obtained; content of said oxides in raw material mixture is no less than 70%; heat treatment of raw material mixture thus prepared is performed in presence of reductant by heating to temperature of 1300-500 C, after which melt is heated to 1800 C and iron-containing product is separated; then, melt is cooled to 1500 C and grinding of product is performed after granulation of melt; oxides contained in granulate have the following ration: (CaO+MgO)/SiO₂-0.5-1.7 and Al₂O₃/SiO₂-0.3-0.6. Water in the amount of 30 to 35% of weight of solid product may be added to ground product. Granulation of melt may be performed by cooling it with natural gas; gas formed after granulation of melt may be used as reductant. Wastes of coal concentration process or low-grade coal may be used as reductant. Ground product may be additionally mixed with finely-dispersed filler at ratio of 1?0.1-2). Ash-and-slag wastes of thermal power plants may be used as finely-dispersed filler. Flyash of coat thermal power plants and red mud of silica production process may be also used as finelydispersed filler. Water in the amount of 30 to 35% of weight of mixture may be added to mixture. Solutions of NaOH and/or KOH and/or Na₂CO₃ and/or Na₂SO₃ and/or K₂SO₃, and/or CaSO₃ may be added to mixture. Amount of said solutions is no less than 2-10 mass/% in terms of dry substance. EFFECT: reduced power requirements; improved quality of product; enhanced ecological safety. 14 cl, 1 dwg