METHOD FOR TREATING EXHAUST GAS CONTAINING FLY ASH

摘要

PROBLEM TO BE SOLVED: To provide a method for treating an exhaust gas containing fly ash capable of decomposing and detoxifying a dioxin and the like by removing the ash containing the dioxin and the like and acid gas contained in the gas generated in a waste incinerating facility and stabilizing the ash. SOLUTION: The method for treating exhaust gas containing fly ash comprises a smoke cleaning step 10 of bringing a hydrochloric acid absorption liquid held at 2.0 to 6.0 of a pH at the gas generated in a waste incinerating facility 1 into contact with a gas to transfer the acid gas and the ash into the liquid to extract a soluble inorganic chlorine and heavy metal contained in the ash by the liquid to stabilize the ash, a dioxin decomposing step 23 of including the liquid containing the stabilized ash obtained in the cleaning step in a reaction catalyst melting state and holding it under a lower temperature condition than 100 deg.C in a pH range of 2.0 to 6.0 to decompose and detoxify the dioxin and the like in the ash, and a treating step of the ash slagged by solid-liquid separating the liquid containing the stabilized ash obtained in the decomposing step and supplying an ash-containing slurry or cake containing the separated stabilized ash to the facility 1 or other incinerating facility.