EFFECTIVE UTILIZATION OF HEAVY METAL ELEMENTS (ANTIMONY ETC.) IN THE REFUSE INCINERATED ASH

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Ash from incinerated general municipal wastes of annual about 50 million tons are discharged from incineration plant. Recent years, the melting processing is mainly advanced as a treating process of the municipal waste, because it is feared that the dioxins and harmful heavy metals such as the arsenic affect the environment. However, the cost of initial plant investment is big and the power consumption necessary for the maintenance becomes also enormous. Besides, it becomes also a problem to continuously run. Ash from incinerated general municipal wastes contains fly ash and bottom ash. Though toxic substances such as heavy metal are mainly included for the fly ash, the toxic substances except for the small lead are not almost included for the bottom ash.In this study, it focuses on fly ash, and then environmental pollution control of toxic substance and effective utilization of fly ash are examined. To begin with, type, concentration and distribution of noxious heavy metals such as the antimony that the toxicity is strong is said by comparing arsenic in incinerated ash, etc. are examined and the particle size distribution of incinerated ash is examined. On the basis of those results, the comparison between the particle size and the content rate of heavy metal is carried out. Next, the recovery of the heavy metal using solvent extraction operation, etc. is tried.