Effect of Cr on the Mineral Structure and Composition of Cement Clinker and Its Solidification Behavior
College of Materials Science and Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
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Materials 2020, 13(7), 1529; https://doi.org/10.3390/ma13071529
Received: 8 March 2020
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Revised: 19 March 2020
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Accepted: 24 March 2020
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Published: 26 March 2020
(This article belongs to the Section Construction and Building Materials)
In order to reveal the solidification behavior of Cr in the cement clinker mineral phase, 29Si magic-angle spinning nuclear magnetic resonance, X-ray diffraction, and scanning electron microscopy with energy-dispersive X-ray spectroscopy techniques were used to analyze the morphology and composition of the cement clinker mineral phase doped with Cr. The results showed that the addition of Cr did not change the chemical environment of 29Si in the clinker mineral phase, and it was still an isolated silicon–oxygen tetrahedron. Cr affected the orientation of the silicon–oxygen tetrahedron and the coordination number of calcium, leading to the formation of defects in the crystal structure of the clinker mineral phase, by replacing Ca2+ into the mineral phase lattice to form a new mineral phase Ca3Cr2(SiO4)3. Cr acted as a stabilizer for the formation of β-C2S in the clinker calcination. As the amount of Cr increased, the relative content of C3S decreased and the relative content of C2S increased. Further, Cr easily dissolved in C2S, while it was not found in C3S. This study is conducive to further research on the mechanism of heavy metal solidification in cement clinker. Furthermore, it is important to evaluate the environmental risk of heavy metals in the process of sludge disposal through cement kiln and promote the utilization of sludge resources and the sustainable development of the cement industry.
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Keywords:
clinker; heavy metal; solidification; 29Si MAS NMR; Cr
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MDPI and ACS Style
Fan, H.; Lv, M.; Wang, X.; Xiao, J.; Mi, X.; Jia, L. Effect of Cr on the Mineral Structure and Composition of Cement Clinker and Its Solidification Behavior. Materials 2020, 13, 1529. https://doi.org/10.3390/ma13071529
AMA Style
Fan H, Lv M, Wang X, Xiao J, Mi X, Jia L. Effect of Cr on the Mineral Structure and Composition of Cement Clinker and Its Solidification Behavior. Materials. 2020; 13(7):1529. https://doi.org/10.3390/ma13071529
Chicago/Turabian StyleFan, Haihong, Mengqi Lv, Xiaosha Wang, Jianmin Xiao, Xiaofan Mi, and Luwei Jia. 2020. "Effect of Cr on the Mineral Structure and Composition of Cement Clinker and Its Solidification Behavior" Materials 13, no. 7: 1529. https://doi.org/10.3390/ma13071529
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