| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for treating ashes collected by a bag filter and by which elution of heavy metals can easily be prevented while the addition amount of a chemical agent is suppressed to the minimum and the running cost and the landfilling amount can be lowered. SOLUTION: In a flue gas treatment method wherein at first fly ashes are collected by passing a flue gas, which is emitted by incinerating wastes or melting and solidifying wastes and which contains incinerator fly ashes or melted fly ashes, through a bag filter 6 in the prior stage and then acidic gases in the flue gas are absorbed and removed by spraying slaked lime to the resultant flue gas from which the fly ashes are removed and passing the flue gas through a bag filter 8 in the posterior stage, about 10 wt.% concentration of a slurry is produced by adding an iron salt 15 of 0.1% or higher based on conversion into Fe to fly ashes 11 under stirring and water as a pH adjusting agent, to fly ashes collected in the bag filter in the posterior stage, and the pH value of the slurry is controlled to be 6-12 by adding an iron salt while stirring the slurry.</p> |
