Method and apparatus for reducing mercury of cement kiln exhaust gas

摘要

An object of the present invention is to efficiently reduce the amount of mercury contained in exhaust gas from a cement kiln at low cost. Cement kiln dusts D2 and D4 contained in a combustion exhaust gas G1 of a cement kiln are separated from a cyclone 4C (or 4B) excluding an uppermost cyclone 4D and a lowermost cyclone 4A of a preheater 4 for preheating a cement raw material R1. A mixing and heating device 19 that heats the cement raw material R2 by sensible heat while mixing with the cement raw material R2, a mercury recovery device 21 that recovers mercury Hg volatilized from the cement kiln dusts D2 and D4, and a mixing and heating device 19 Mercury of cement kiln exhaust gas provided with a supply device for supplying mercury removing dust D5, D6 discharged from the cyclone 4B (or 4A) located below the cyclone 4C (or 4B) from which the cement raw material R2 is separated Reduction device 11. [Selection] Figure 1