EXHAUST GAS TREATMENT METHOD

PROBLEM TO BE SOLVED: To provide an exhaust gas treatment method capable of supplying the appropriate amount of caustic soda aqueous solution and slaked lime powder so as to reduce a slaked lime supply amount, evade the excess supply of the caustic soda aqueous solution and surely remove an acidic gas. SOLUTION: The exhaust gas treatment method includes: a cooling process of cooling an exhaust gas to 200°C or lower in a gas cooling tower 10; an acidic gas removal process of supplying the caustic soda aqueous solution and slaked lime powder to cooled exhaust gas and neutralizing the acidic gas in a flue between the gas cooling tower and a bag filter 70 or at the entrance of the bag filter 70; and a dust collecting process of removing dust in the exhaust gas by the bag filter 70, removing the reaction product of the acidic gas and the caustic soda aqueous solution, and then removing the reaction product of the acidic gas and the slaked lime powder. The ratio of the equivalent ratio of the caustic soda aqueous solution to the total of the equivalent ratio of the supplied caustic soda aqueous solution and the equivalent ratio of the slaked lime powder is controlled to 0.2-0.3. COPYRIGHT: (C)2011,JPO&INPIT