FIELD: construction materials.
SUBSTANCE: invention relates to construction materials and can be used in production of cements for various purposes with active mineral additives and an auxiliary component. Method of producing cement with low clinker content involves mixing and joint grinding of portland cement clinker with gypsum and an active mineral additive in the form of aluminium-silicon-containing wastes of processing mineral raw materials from thermal power plants from burning coal (flue ash and slag). At that, aluminium-silicon-containing wastes (ASW) are subjected to magnetic separation to separate ferromagnetic impurities for their utilization as a separate product, after which ASW is accumulated in a vertical tank and moistened with a circulating solution to moisture content of 40-60%, then the first part of the accumulated ASW is removed from the bottom of the tank and filtered to obtain a first cake and a first aqueous solution, then the second part of accumulated ASW is removed from the bottom of the tank and mixed with the first aqueous solution to obtain a suspension of the second part of the accumulated ASW of the required fluidity for supply into the inner cavity of the device, through which waste flue gases from the cement furnace are passed. Obtained suspension of the second part of ASW is removed from the device for interaction with flue gas substances and mixed with the first cake of accumulated ASW to obtain a combined mixture of the first and second parts of ASW, which is filtered to obtain a third cake of ASW and a third aqueous solution, which is prepared as a recycled solution by mixing with such an amount of calcium quicklime until its complete slaking, at which concentration of hydrated lime in this solution is 0.01-0.09 mol./l. Then the third cake of ASW is mixed with finely dispersed calcium sulphate, weight fraction of which of dry ASW weight of the third cake is 0.1-5% in terms of sulphur oxide (VI). Obtained mixture of ASW with sulphates is dried to moisture content of not more than 0.1-3% and supplied, in amount of 5-40% of the weight of the Portland cement clinker, for mixing and joint grinding with Portland cement clinker and gypsum, wherein amount of supplied gypsum, from weight of Portland cement clinker, is 0.5-8% in terms of sulphur oxide (VI).
EFFECT: providing stable activity of cement with low content of clinker containing an active mineral additive with required pozzolanic properties.
7 cl, 1 dwg, 1 tbl, 6 ex
