建設材料 電気集じん機により段別採取したフライアッシュの特性と脱炭素処理によるフライアッシュの改質

Abstract

This paper discusses the chemical, physical and mineralogical properties of classified fly ashes by using of electrostatic precipitator and modified fly ashes by calcination at 500°C or plasma reactor. In addition, the influences of burning conditions and types of coals on the properties of fly ashes are investigated. It is proposed that the electrostatic precipitator can also be applied to the separator. The electrostatic precipitator in coal fired power plant has a number of hopper in the direction of flue gases. Blaine values of fly ashes collected at 1st, 2nd and 3rd hoppers are respectively about 3000 (ordinary), 5000 (fine) and 8000cm2/g (superfine), regardless of burning condition and types of coals. The glass contents of fly ashes become greater as their blaine values are raised. The adiabatic temperature rise of mortar containing fly ash is increased with the fineness of fly ash. The pozzolanic reactivity of fly ash at early stage and at later stage are respectively related to the fineness and the glass contents of fly ash. But, the early hydration of cement was retarded by addition of superfine fly ashes. The carbon content in fly ash influences on the paste fluidity. The carbon content in fly ash is decreased by calcination and plasma treatment and the fluidity of paste is improved by the removal of carbon, .