کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
577230 1453097 2013 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بهداشت و امنیت شیمی
پیش نمایش صفحه اول مقاله
Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials
چکیده انگلیسی
In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, 27Al MAS NMR and 29Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of AlIV and AlVI, but mainly in the form of AlVI. Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO4] to [AlO6] and inhibits the combination between [AlO4] and [SiO4] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO4] in the hydration products declines.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 262, 15 November 2013, Pages 428-438
نویسندگان
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