Reddy Kamasani Chiranjeevi, Seo Joonho, Yoon H N, Kim Seonhyeok, Kim G M, Son H M, Park Seunghee, Park Solmoi
Department of Civil Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 48513, Korea.
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
Materials (Basel). 2022 Aug 25;15(17):5873. doi: 10.3390/ma15175873.
The phase changes in alkali-activated slag samples when exposed to supercritical carbonation were evaluated. Ground granulated blast furnace slag was activated with five different activators. The NaOH, NaSiO, CaO, NaSO, and MgO were used as activators. C-S-H is identified as the main reaction product in all samples along with other minor reaction products. The X-ray diffractograms showed the complete decalcification of C-S-H and the formation of CaCO polymorphs such as calcite, aragonite, and vaterite. The thermal decomposition of carbonated samples indicates a broader range of CO decomposition. Formation of highly cross-linked aluminosilicate gel and a reduction in unreacted slag content upon carbonation is observed through Si and Al NMR spectroscopy. The observations indicate complete decalcification of C-S-H with formation of highly cross-linked aluminosilicates upon sCO carbonation. A 20-30% CO consumption per reacted slag under supercritical conditions is observed.
评估了碱激发矿渣样品在超临界碳酸化条件下的相变。采用五种不同的激发剂对磨细粒化高炉矿渣进行激发。使用氢氧化钠、硅酸钠、氧化钙、硫酸钠和氧化镁作为激发剂。在所有样品中，除了其他少量反应产物外，C-S-H被确定为主要反应产物。X射线衍射图显示C-S-H完全脱钙，并形成了方解石、文石和球霰石等碳酸钙多晶型物。碳酸化样品的热分解表明二氧化碳分解范围更广。通过硅和铝核磁共振光谱观察到，碳酸化后形成了高度交联的铝硅酸盐凝胶，未反应矿渣含量降低。观察结果表明，在超临界二氧化碳碳酸化作用下，C-S-H完全脱钙，形成了高度交联的铝硅酸盐。在超临界条件下，每反应的矿渣消耗20-30%的二氧化碳。
