Petrus Himawan Tri Bayu Murti, Olvianas Muhammad, Shafiyurrahman Muhammad Faiz, Pratama I Gusti Agung Arvin Nanda, Jenie Siti Nurul Aisyiyah, Astuti Widi, Nurpratama Muhammad Istiawan, Ekaputri Januarti Jaya, Anggara Ferian
Department of Chemical Engineering (Sustainable Mineral Processing Research Group), Faculty of Engineering, Universitas Gadjah Mada, Jalan Grafika 2, Yogyakarta 55281, Indonesia.
Unconventional Geo-Resources Research Group, Faculty of Engineering, Universitas Gadjah Mada, Jalan Grafika 2, Yogyakarta 55281, Indonesia.
Gels. 2022 Apr 11;8(4):233. doi: 10.3390/gels8040233.
The study of geopolymers has become an interesting concern for many scientists, especially in the infrastructure sector, due to having inherently environmentally friendly properties and fewer energy requirements in production processes. Geopolymer attracts many scientists to develop practical synthesis methods, useful in industrial-scale applications as supplementary material for concrete. This study investigates the geopolymerization of fly ash and geothermal silica-based dry activator. The dry activator was synthesized between NaOH and silica geothermal sludge through the calcination process. Then, the geopolymer mortar was produced by mixing the fly ash and dry activator with a 4:1 (wt./wt.) ratio. After mixing homogeneously and forming a paste, the casted paste moved on to the drying process, with temperature variations of 30, 60, and 90 °C and curing times of 1, 3, 5, 7, 14, 21, 28 days. The compressive strength test was carried out at each curing time to determine the geopolymer's strength evolution and simulate the reaction's kinetics. In addition, ATR-FTIR spectroscopy was also used to observe aluminosilicate bonds' formation. The higher the temperature, the higher the compressive strength value, reaching 22.7 MPa at 90 °C. A Third-order model was found to have the highest R value of 0.92, with the collision frequency and activation energy values of 1.1171 day and 3.8336 kJ/mol, respectively. The utilization of coal fly ash and silica geothermal sludge as a dry activator is, indeed, an approach to realize the circular economy in electrical power generations.
由于地质聚合物具有本质上环保的特性且生产过程中能源需求较少，因此对其研究已成为许多科学家关注的焦点，尤其是在基础设施领域。地质聚合物吸引了众多科学家去开发实用的合成方法，这些方法在工业规模应用中可作为混凝土的补充材料。本研究调查了粉煤灰与基于地热硅的干式活化剂的地质聚合反应。干式活化剂是通过煅烧过程在氢氧化钠和地热硅污泥之间合成的。然后，通过将粉煤灰和干式活化剂按4:1（重量/重量）的比例混合来制备地质聚合物砂浆。均匀混合并形成糊状物后，将浇铸好的糊状物进行干燥处理，温度分别为30、60和90°C，养护时间为1、3、5、7、14、21、28天。在每个养护时间进行抗压强度测试，以确定地质聚合物的强度发展并模拟反应动力学。此外，还使用衰减全反射傅里叶变换红外光谱法（ATR-FTIR）来观察铝硅酸盐键的形成。温度越高，抗压强度值越高，在90°C时达到22.7MPa。发现三阶模型的R值最高，为0.92，碰撞频率和活化能值分别为1.1171天和3.8336kJ/mol。利用粉煤灰和地热硅污泥作为干式活化剂确实是一种在发电领域实现循环经济的方法。
