METHOD AND APPARATUS FOR TREATING DUST IN BLEED GAS OF CEMENT KILN COMBUSTION GAS

摘要

PPROBLEM TO BE SOLVED: To enhance purity of recovered heavy metals and gypsum at low equipment and operation costs in recovering the heavy metals from dust in a bleed gas of a cement kiln combustion gas. PSOLUTION: An apparatus 1 and the like for treating the dust in a bleed gas of a cement kiln combustion gas includes a bleeder 6 to cool and bleed part of the combustion gas from a kiln exhaust gas duct between the outlet port 5a of a cement kiln 5 and a lowermost cyclone; a wet dust collector 11 to perform wet collection of the dust D2 contained in the bleed gas G1 bled by the bleeder, removing sulfur oxides contained in the bleed gas, and to adjust the pH of a slurry S1 formed in the wet dust collection and desulfurization so that the heavy metals contained in the slurry dissolve in the liquid phase of the slurry; a first solid/liquid separator 21 to perform solid/liquid separation of the slurry of which the pH is adjusted by the wet dust collector; and a second solid/liquid separator 23 to separate and recover the heavy metals from a filtrate W1 separated by the first solid/liquid separator. PCOPYRIGHT: (C)2011,JPO&INPIT