PRODUCTION OF CONCRETE ADMIXTURE FROM COAL ASH

摘要

PURPOSE:To produce a concrete admixture from coal ash with a reduced evolution of NOx and a little energy consumption. CONSTITUTION:A combustion furnace 40 is charged with coal from a coal hopper 42, coal ash from a coal ash hopper 43 and oxygen 59. In the combustion furnace 40 and SiO2 in the coal ash is selectively vaporized, flows into a cooler 41, is cooled by air 56 sent from a blow fan 45 and a SiO2 gas is condensed to provide a high-temperature gas containing ultrafine particles of SiO2. The sensible heat of a high-temperature exhaust gas is recovered by a heat exchanger 46. Oxygen 59 to be supplied to the combustion furnace 40 is produced by an oxygen producing device 57 by a temperature swing method of a molten alkali salt. The molten alkali salt in the oxygen producing device 57 is heated by the heat exchanger 46.