| 摘要 |
PROBLEM TO BE SOLVED: To provide a low cost recycling process, as a means for recovering a valuable metal from a waste to be treated by a heating device, by which it is possible to effectively enhance the quality level of the valuable metal contained in fly ash and mitigate the load of a metal recovering operation in an after-process using the fly ash as a raw material. SOLUTION: An additive which reacts with and forms a bond with a valuable metal is added to fly ash and/or an additive which reacts with and forms a bond with an unnecessary component to separate the same from the fly ash is added to the fly ash. Then the mixture is returned to a heating device to thermally treat it a plurality of times. Thus the fly ash containing the highly concentrated valuable metal is obtained. The heating temperature in the thermal treatment is preferably as high as 500-1,400 deg.C and a heating atmosphere is made to be a reduction atmosphere.
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