TREATMENT OF WASTE GAS CONTAINING FLY ASH AND TREATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a treating method and a treating device for waste gas containing fly ash capable of reducing the volume of a dumping material by recycling the fly ash to a melting furnace to convert the ash to slag. SOLUTION: At the time of removing an acidic gas and fly ash from the waste gas containing the fly ash and the acidic gas generated at a gasifying and melting process of the waste, sulfur oxide is immobilized as a sulfate ion by subjecting the waste gas discharged from the melting furnace 40 and containing the acidic gas and the fly ash to gas-liq. contact with an absorbing liq. kept within a range of pH 2.0-6.0 and containing an alkali component as an absorbing agent to absorb the acidic gas into the absorbing liq. and moreover to oxidize the acidic gas at a reaction tank 1, and also the fly ash is stabilized by extracting heavy metals incorporated in the fly ash. Then a cake or slurry containing the stabilized fly ash subjected to solid.-liq. separation from the absorbing liq. is returned from a return pipe 22 to the melting furnace 40 to convert it into the slag.