Quantitative characterization of aluminosilicate gels in alkali-activated incineration bottom ash through sequential chemical extractions and deconvoluted nuclear magnetic resonance spectra

• Main Authors: Zhu, Weiping, Chen, Xu, Struble, Leslie J., Yang, En-Hua
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Civil engineering; Municipal Solid Waste; Incineration Bottom Ash
• Online Access: https://hdl.handle.net/10356/152125
• Institution: Nanyang Technological University

It has been reported that incineration bottom ash (IBA) from municipal solid waste can be a potential precursor for the synthesis of alkali-activated materials. It has been reported that the resulting alkali-activated IBA (AA-IBA) binder consists of 20 wt% calcium-containing phases. It is expected that aluminosilicate phases may coexist in the complex AA-IBA binder. Differentiating aluminosilicate phases from C-(A)-S-H phases could be challenging, for in general the two phases largely overlap in the spectra. In this study, aluminosilicate gels in a complex AA-IBA are separated and quantitatively characterized based on sequential chemical extractions, thermogravimetric analysis and nuclear magnetic resonance spectral subtraction and deconvolution. It concludes that the resulting AA-IBA binder consists of 17 wt% aluminosilicate gel with a Si/Al ratio of 2.52 resembling an aged alkali-activated coal fly ash. As understanding gel compositions in a binder is important, the methodology developed in this study is of significance and would benefit the development of alternative binders incorporating solid wastes and industry by-products.