Solidification Technique for Fluorine Contaminated-Bassanite Using Composite Recycling Materials for Ground Improvement Applications

機関リポジトリ HANDLE

この論文をさがす

抄録

Waste management is a serious problem over the world due to the huge amount of waste materials produced and increased annually. This paper investigates the development of solidification technology, based on the formation of ettringite, for fluorine contaminated bassanite using waste and recycled materials. For this purpose, recycled bassanite was mixed with coal ash, blast furnace slag and furnace cement type-B in different proportions to obtain the optimal production for ettringite based on their chemical responses. Leaching tests were performed on these different admixtures to measure the solubility of fluorine. Scan electron microscope (SEM) and X-ray diffraction (XRD) tests were conducted on the investigated samples to explore the formation and intensity of ettringite. Results show that the suggested admixture has a significant effect on the production of ettringite and increasing cement content in admixture increases the formation of ettringite. The increase of the ratio of cement-admixture has a clear effect on the production of ettringite and the reduction of fluorine solubility compared to the case of cement-bassanite mixture. Both size and length of ettringite crystals are increasing with the increase of the ratio of cement-admixture/bassanite and intensity of ettringite in material matrix. The solubility concentration of fluorine decreases with the increase of admixture content due to concomitant increase in the production of ettringite. Dimensions of ettringite crystals have a significant effect on the reduction of the solubility of fluorine, the increase of ettringite prisms the decrease of fluorine solubility. The investigated limits of the suggested admixture did not show any adverse effect on the geo-environment properties in term of the release of fluorine. The suggested admixture is recommended to be used as stabilizer material for soft clay soil since it is friendly with environment, economic and meet the standards of environment in Japan.

収録刊行物

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ