Method and apparatus for reducing mercury content of cement kiln exhaust gas

An apparatus for reducing mercury content of cement kiln exhaust gas comprising:

• a first feeder configured to receive cement kiln dust included in a cement kiln combustion gas;
• a mixing and heating device in operative communication with the first feeder to receive cement kiln dust therefrom, the mixing and heating device being configured to be placeable in operative communication with a cyclone other than a highest stage cyclone and a lowest stage cyclone of a preheater for preheating cement raw material to receive cement raw material withdrawn therefrom and to mix the received cement kiln dust into the received cement raw material while heating the cement kiln dust through sensible heat of the withdrawn cement raw material;
• a mercury recovery device for recovering mercury vaporized from the cement kiln dust by the mixing and heating;
• and
• a second feeder for feeding a mixture of the cement kiln dust and the cement raw material discharged from the mixing and heating device to a cyclone positioning at a lower stage from the cyclone from which the cement raw material is withdrawn.