Abstract
The changes of leaching behavior and chemical states for Pb and Cu in various conditions of heat-treated fly ash, which were generated from a gasification melt furnace and stoker-type municipal waste incinerator, were investigated. In this study, chemical states for trace elements on fly ash (e.g. Pb and Cu) were investigated by XAFS spectroscopy at beam line BL01B1 in SPring-8. In the case of agitating fluidized bed heating in air, the leaching rate of Pb and Cu were decreased, and the chemical state of the oxides was estimated and found to be in a more dissolvable state than PbO, CuCI and CuC12⋅ 3 Cu (OH) 2. In heat-treatment in a crucible, the leaching rate of Pb and Cu were not decreased in the pH range 12.5-13.0, and the chemical states of the mixture of chloride and oxide were estimated. We considered that the leaching behavior of Pb and Cu were controlled by oxidizing and forming a dissoluble chemical state when the fly ash was heated under good contact efficiency of gas and fly ash.
