著者
万福 裕造 八田 珠郎 矢板 毅 佐藤 努
出版者
一般社団法人 日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.56, no.2-3, pp.28-40, 2017-12-25 (Released:2018-01-15)
参考文献数
26

In this study, we examined the mineralogical and chemical properties of the 11 soils weathered from different rock-types and Kanto loam, and their properties after heat treatment at 1550°C.The constituent mineral of the weathered soils does not necessarily reflect the mineral and chemical compositions of the host rock. The sum of SiO2, Al2O3, Fe2O3 in the weathered soil shares a considerable ratio as weathered materials while it's not necessarily reflect the chemical composition of the base material rock.With heat treatment of the 11 weathered soils and Kanto loam at 1550°C, the considerable weight loss and phase change was observed. The minerals produced after heating at 1550°C were mullite, cristobalite, hematite. While cristobalite is formed from all soils, mullite and hematite were existed after limited soil treatment. From this chemical weathering index (WI), the formation of mullite from the soil where the weathering is considerably advanced was clarified.The correlation between the formation of hematite and WI is not clear, but the dependence of the content of Fe2O3 is considered. After the heat treatment, significant weight loss was observed in the soils containing large amount of Fe2O3, weathered from andesite, basalt, gabbros, serpentinite, limestone as base materials and Kanto loam. It is thought that it depends on the difference of the content of clay minerals, the dehydration due to the change of clay minerals etc., and the reduction of iron (III) oxide. The basic data obtained in this study are considered to be important for future direction toward the heat treatment and volume reduction of the actual radioactive Cs-contaminated soil in Fukushima Prefecture.