Chen Yuxiang, Wu Shengping, Huang Hanhui, Rao Feng, Yang Lang
Zijin School of Geology and Mining, Fuzhou University, Fuzhou 350108, China.
Fujian Provincial Key Laboratory of Green Extraction and High-Value Utilization of New Energy Metals, Fuzhou 350108, China.
Materials (Basel). 2024 Sep 6;17(17):4409. doi: 10.3390/ma17174409.
This study aims to compare the effects of three calcium compounds on the workability, setting time and mechanical properties of red mud (RM)-blast furnace slag (BFS)-based geopolymers. The crystalline phase, hydration process and microstructure of RM-BFS-based geopolymers were characterized by X-ray diffraction (XRD), heat evolution, X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) tests. The results showed that an appropriate amount of calcium compounds can improve the flowability and compressive strength of the geopolymers, but the excessiveness causes a decrease in strength due to rapid hardening. Other than calcium carbonate, both calcium oxide and calcium chloride played important roles in accelerating the setting times of RM-BFS-based geopolymers. The acceleration in the setting times of geopolymers could be attributed to the calcium hydroxide produced by the dissolution of the calcium compounds, which also provides nucleation sites for the geopolymerization reaction. This study gives new insights into the effect of calcium on the setting times and mechanical properties of geopolymers in the geopolymerization process.
本研究旨在比较三种钙化合物对基于赤泥（RM）-高炉矿渣（BFS）的地质聚合物的工作性、凝结时间和力学性能的影响。通过X射线衍射（XRD）、热演化、X射线光电子能谱（XPS）和扫描电子显微镜（SEM）测试对基于RM-BFS的地质聚合物的晶相、水化过程和微观结构进行了表征。结果表明，适量的钙化合物可以提高地质聚合物的流动性和抗压强度，但过量会由于快速硬化导致强度下降。除碳酸钙外，氧化钙和氯化钙在加速基于RM-BFS的地质聚合物的凝结时间方面都起着重要作用。地质聚合物凝结时间的加速可归因于钙化合物溶解产生的氢氧化钙，其也为地质聚合反应提供了成核位点。本研究为钙在地质聚合过程中对地质聚合物凝结时间和力学性能的影响提供了新的见解。
