【Special Issues: Recycling and Resourse Recovery of Inorganic Solid Wastes】
Resource Recoveryof Inorganic Waste
――Conversion into Environmental Purification Materials――
Michihiro Miyake* and Motohide Matsuda*
* Department of Environmental Chemistry and Materials, Okayama University
† Correspondence should be addressed to Michihiro Miyake:
Department of Environmental Chemistry and Materials, Okayama University
（Tsushima-Naka, Okayama, 700-8530 Japan）

Abstract
Resource recovery of waste incineration fly ash and industrial dust, exhausted from cupola, have been investigated. It was found that waste incineration fly ash treated in the presence of NaOH solution using the hydrothermal method exhibited removal properties for toxic cations. Pre-treatment of waste incineration fly ash with repeated water washing and heating at 800℃ was essential for preparing reproducible tobermorite as a major product at 180℃. On the other hand, pre-treatment with HCl solution, in addition to the repeated water washing and heating at 800℃, was essential for preparing reproducible zeolites A and P as major products at 60−120℃. Cupola dust treated in the presence of NaOH solution using the hydrothermal method was found to exhibit sorptive property for H2S gas. The property was induced by spinel nanocrystals such as（MnxZn1−x）（MnyFe1−y）2O4 solid solution in the cupola dust.

Key words: resource recovery, waste incineration fly ash, cupola dust, hydrothermal treatment, environmental cleanup materials