FIELD: waste processing and disposal.
SUBSTANCE: invention relates to processing of ash-slag wastes (ASW) of current output of thermal power plants and thermal cogeneration plants operating at coal-fuels, for the purpose of large-scale industrial recycling of processed ASW as active mineral additives for cement, concrete and other materials in production of construction articles. Method of processing ash-slag wastes at coal thermal power plants for production of construction products includes heat treatment in rotary furnace, providing sublimation of alkalis with subsequent removal thereof with exhaust furnace gases into aspiration system, in temperature range 1,200–1,600 °C slag melt, mixed with fly ash, taken directly from bins installed under ash catchers of power plant boilers, fast cooling of produced mixture by air-water jets at its aero-hydrodynamic spraying, drying the processed mixture to moisture content of not more than 1 % with subsequent magnetic separation for separation of iron oxides contained in the mixture, at that, alkali and iron oxides recovered from the mixture are recycled as independent products, separation of the processed dry mixture into two fractions – average size within range of 40–50 mcm and not more than 120 mcm and more than 120 mcm, wherein fraction of not more than 120 mcm, if necessary, is recycled as an independent product, and the mixture fraction of more than 120 mcm is subjected to fine dry grinding together with additives hardening type lime or cement clinker with additionally added additives hardening type activators of gypsum and/or aluminum sulphate and materials from screenings of crushing carbonate rocks with subsequent separation of said ground mixture in a closed cycle by separation into a ready mixture with a given fineness and grits, which is returned after separation for grinding, final mixing of all obtained components and storage, wherein amount of introduced double-gypsum is 0.5–3.5 % of dry weight of processed mixture of slag melt with fly ash, and amount of aluminum sulphate is 0.1–3 % of dry weight of processed mixture slag melt with fly ash, wherein total amount of all additives is 1–15 % of dry weight of processed mixture of slag melt and fly ash.
EFFECT: providing stable characteristics and guaranteed quality of ash-slag wastes processing products.
1 cl, 1 dwg, 1 ex
