| 摘要 |
PROBLEM TO BE SOLVED: To decompose/detoxify dioxins in burned ash and to stabilize heavy metals simultaneously by making the burned ash contact a gaseous medium containing steam at a specified temperature in the presence of an alkaline substance. SOLUTION: Crushed, and pretreated burned ash 2 with iron components removed is supplied to a drier 22, where the ash is dried by evaporating water, and is contacted with a gaseous medium containing oxygen at 300 deg.C or above, and unburned substances contained in the ash is burned enough. the dried ash discharged from the drier 22 is crushed into particles of 10 mesh undersize by a crusher 23. The crushed, and dried ash 3 is supplied to a treatment/reaction apparatus 24 together with an alkaline substance additive 4. In the apparatus 24, the ash 3 is contacted with a gaseous medium containing steam at 600-980 deg.C in the presence of an alkaline substance. In this way, dioxins are decomposed/ detoxified, and treated ash 6 with heavy metals stabilized/detoxified is obtained.
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