Feasibility study on heavy metals recovery from fly ash of ash melting furnace by utilizing existing production facilities as social resources

摘要

Since fly ash generated in ash melting furnace involves valuable nonferrous materials, especially zinc and lead, the materials should be extracted and reused for production from viewpoint of resource recovery. Zinc and lead in the ash can be recovered in a smelting furnace named ICP, which is a large scale furnace to smelt ore. Ash with high chlorine concentration needs pre-treatment to remove chlorine and the salt by thermal operation or rinsing. Hence, it is important to minimize recovery energy and CO{sub}2 emission in the processes and material transportation. In this study, it is considered that the melting furnace fly ash and/or the pre-treated matter are transported over a long distance in Japan by tracks and/or ships and an existing nonferrous metal smelting facility and a pretreatment facility are utilized as much as possible. From the evaluation of possible paths to recover the zinc and lead from the melting furnace fly ash it was found the path of transporting fly ash to the existing pre-treatment facility by ship and treating it together with a large amount of other ash lowers energy consumption and CO{sub}2 emission.