| 摘要 |
PROBLEM TO BE SOLVED: To surely make heavy metals of lead, etc., in dry method fly ash stable and harmless as insoluble sulfide such as lead sulfide by a method in which after cement and water being added and mixed into dry method fly ash, the mixture is added with calcium sulfide and kneaded. SOLUTION: When dry method fly ash generated from an incinerator, a melting furnace, etc. is treated, after the fly ash being added with cement and water to be mixed into sludge slurry-shaped mixture, the mixture is added with calcium sulfide and kneaded. By this mixing order, the insolubilization effect of heavy metals by calcium sulfide is strengthened so that the elution of heavy metals into water from a disposal kneaded material can be prevented surely. In this process, preferably 100 pts.wt. of the fly ash 100 containing 10-50wt.% of a lime component is added with 1-30 pts.wt. of cement and 30-60 pts.wt. of water and they are mixed. After that, the mixture is added with 1-5 pts.wt. of calcium sulfide, and the alkaline mixture of 10 or more pH is kneaded and treated. |
