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Preparation of blended geopolymer from red mud and coal gangue with mechanical co-grinding preactivation
Abstract In preparing geopolymer based on red mud (RM), preactivation processes that are generally energy-intensive are employed, including two indispensable steps, namely, calcination and fine grinding. A novel co-grinding preactivation method without calcination was proposed in this study. RM was pretreated by mix grinding with blended coal gangue (CG) (weight ratio of 8:2) for 20 min. The powdered mixture was characterized by alumina silicate dissolution efficiency test, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy. The corresponding geopolymer was also synthesized and characterized by XRD and scanning electron microscopy to assess the mechanical properties and polymerization reaction. Results showed that under co-grinding effect, the main alumina silicates of the RM/CG mixture were transformed into low-coordinated or low-polymerized phases. The phases were then dissolved in alkaline solution and repolymerized. Alkali activation with high compressive strengths completely formed dense amorphous geopolymer matrices. This work demonstrated that CG, as a milled conditioner, could efficiently expedite the preactivation of RM by grinding without calcinations. Moreover, an RM/CG-based geopolymer was successfully synthesized from the preactivated mixture.
Preparation of blended geopolymer from red mud and coal gangue with mechanical co-grinding preactivation
Abstract In preparing geopolymer based on red mud (RM), preactivation processes that are generally energy-intensive are employed, including two indispensable steps, namely, calcination and fine grinding. A novel co-grinding preactivation method without calcination was proposed in this study. RM was pretreated by mix grinding with blended coal gangue (CG) (weight ratio of 8:2) for 20 min. The powdered mixture was characterized by alumina silicate dissolution efficiency test, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy. The corresponding geopolymer was also synthesized and characterized by XRD and scanning electron microscopy to assess the mechanical properties and polymerization reaction. Results showed that under co-grinding effect, the main alumina silicates of the RM/CG mixture were transformed into low-coordinated or low-polymerized phases. The phases were then dissolved in alkaline solution and repolymerized. Alkali activation with high compressive strengths completely formed dense amorphous geopolymer matrices. This work demonstrated that CG, as a milled conditioner, could efficiently expedite the preactivation of RM by grinding without calcinations. Moreover, an RM/CG-based geopolymer was successfully synthesized from the preactivated mixture.
Preparation of blended geopolymer from red mud and coal gangue with mechanical co-grinding preactivation
Geng, Junjun (author) / Zhou, Min (author) / Zhang, Ting (author) / Wang, Weixing (author) / Wang, Teng (author) / Zhou, Xian (author) / Wang, Xiaoshu (author) / Hou, Haobo (author)
Materials and Structures ; 50 ; 1-11
2016-12-12
11 pages
Article (Journal)
Electronic Resource
English
| British Library Online Contents | 2017
| British Library Online Contents | 2017