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Synthesis and Characterization of Geopolymer from Bayer Red Mud with Thermal Pretreatment
Author(s) -
Ye Nan,
Yang Jiakuan,
Ke Xinyuan,
Zhu Jing,
Li Yalin,
Xiang Cheng,
Wang Huabin,
Li Lei,
Xiao Bo
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12840
Subject(s) - red mud , geopolymer , calcination , materials science , dissolution , bayer process , aluminosilicate , solubility , compressive strength , microstructure , composite number , chemical engineering , ground granulated blast furnace slag , metakaolin , mineralogy , composite material , metallurgy , chemistry , aluminium , fly ash , catalysis , organic chemistry , engineering
A composite geopolymeric material was synthesized from Bayer red mud combined with granulated blast‐furnace slag. Thermal pretreatment was applied to improve the solubility of red mud in alkaline solution to promote geopolymerization. The dissolution efficiencies of alumina and silica reached a maximum when red mud was calcined at 800°C, resulting in the highest compressive strength of binders. It was demonstrated that a higher solubility of calcined red mud led to a higher strength of the composite binders. The characteristic microstructures of hydration products were studied to illustrate the geopolymerization process by XRD , FTIR and SEM . The results showed that aluminosilicates were dissolved in the alkaline solution to form nanostructural particulates during the early dissolution process, and then accumulated to form highly dense geopolymeric matrices through solidification reaction. The coexistence of geopolymer and C–(A)–S–H is suggested to contribute to the good performance of the composite binders.