Hubei Key Laboratory of Mineral Resources Processing and Environment, Luoshi Road 122, Wuhan, Hubei, 430070, China; CONACYT Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mich., 58030, Mexico.
Hubei Key Laboratory of Mineral Resources Processing and Environment, Luoshi Road 122, Wuhan, Hubei, 430070, China.
Chemosphere. 2020 Aug;253:126754. doi: 10.1016/j.chemosphere.2020.126754. Epub 2020 Apr 11.
This study sought to analyze the effect of curing temperature on mechanical strength and microstructure of a copper tailing-based geopolymer via scanning electron microscopy (SEM), HCl extraction, nuclear magnetic resonance (NMR), and X-ray diffraction (XRD). The distribution of gel formed in geopolymers tended to be uniform with increasing curing temperature from 25 to 80 °C. Moreover, the percentage of Si sites in C-S-H and N-A-S-H gels increased from 62.08% to 78.94% and more tetrahedral [AlO] was incorporated into the tetrahedron [SiO] backbone, leading to an increase of compressive strength from 10.2 to 39.6 MPa. When the curing temperature was increased to 120 °C, the percentage of Si sites in C-S-H and N-A-S-H gel decreased to 69.52%, and the compressive strength decreased to 27.5 MPa. Moderately elevated curing temperature promoted the dissolution of aluminosilicate while curing temperatures above 80 °C hindered it. Excessive curing temperature led to a decrease in the geopolymer alkaline medium.
本研究通过扫描电子显微镜（SEM）、盐酸提取、核磁共振（NMR）和 X 射线衍射（XRD）分析了养护温度对基于铜尾矿的地质聚合物机械强度和微观结构的影响。随着养护温度从 25°C 升高到 80°C，地质聚合物中形成的凝胶分布趋于均匀。此外，C-S-H 和 N-A-S-H 凝胶中 Si 位的百分比从 62.08%增加到 78.94%，更多的四面体[AlO]被掺入到四面体[SiO]骨架中，导致抗压强度从 10.2MPa 增加到 39.6MPa。当养护温度升高到 120°C 时，C-S-H 和 N-A-S-H 凝胶中 Si 位的百分比下降到 69.52%，抗压强度下降到 27.5MPa。适度升高养护温度促进了铝硅酸盐的溶解，而养护温度高于 80°C 则阻碍了其溶解。过高的养护温度会降低地质聚合物的碱性介质。
