Tang Song, Peng Tongjiang, Sun Hongjuan, Ding Wenjin, Luo Liming
School of Environment and Resources, Southwest University of Science and Technology, Mianyang 621010, China.
Institute of Mineral Materials and Application, Southwest University of Science and Technology, Mianyang 621010, China.
Materials (Basel). 2023 Jan 19;16(3):937. doi: 10.3390/ma16030937.
Hardened pastes with different mass percentages of steel slag (SS)/titanium-extracted tailing slag (TETS) were prepared under fixed CaO content to determine the influencing mechanism of TETS on the strength of CaO SS hardened paste. Furthermore, the effects and laws of curing time and SS/TETS ratios on the strength of hardened pastes were also investigated in this study. Importantly, hydration products, microstructures and the micro-area compositions of hardened pastes were analysed using X-ray diffraction, Fourier-transform infrared spectroscopy and scanning electron microscopy-energy dispersive spectrometer, respectively, to reveal the influencing mechanism of TETS on the CaO SS hardened pastes. The results demonstrated that the early strength of hardened pastes increases considerably following the inclusion of TETS. Specifically, the strength of the sample with an SS/TETS ratio of 22.5:67.5 at 1 d can be increased by more than 14 times. Notably, its strength at 90 days reached 19.36 MPa. Moreover, the diffraction peaks of calcite and C-S-H in the samples were also strengthened. Meanwhile, a diffraction peak of hydrocalumite appeared, and the calcites in the samples were curled up. When the SS/TETS ratio was equal to or more than 45:45, a diffraction peak of Ca(OH) appeared in the sample. Only a diffraction peak of Ca(OH) and weak diffraction peaks of calcite and C-S-H were observed in the samples without TETS, but there was no diffraction peak of hydrocalumite. The strength at 90 days was only 4.92 MPa. The increased strength of the hardened paste is closely related to the production of new phases after adding TETS. Solid particles in the hardened paste are cemented into a whole because of the hydration of C-S-H. Calcite forms the skeleton of the hardened pastes, whereas hydrocalumite fills in the pores among particles in hardened pastes, thus making them more compacted. As a result, there is increased.
在固定CaO含量的条件下，制备了不同质量百分比的钢渣（SS）/提钛尾渣（TETS）硬化浆体，以确定TETS对CaO-SS硬化浆体强度的影响机制。此外，本研究还考察了养护时间和SS/TETS比例对硬化浆体强度的影响及规律。重要的是，分别利用X射线衍射、傅里叶变换红外光谱和扫描电子显微镜-能谱仪分析了硬化浆体的水化产物、微观结构和微区组成，以揭示TETS对CaO-SS硬化浆体的影响机制。结果表明，加入TETS后，硬化浆体的早期强度显著提高。具体而言，SS/TETS比例为22.5:67.5的样品在1天时的强度可提高14倍以上。值得注意的是，其90天时强度达到19.36MPa。此外，样品中方解石和C-S-H的衍射峰也得到增强。同时，出现了碳铝酸钙的衍射峰，样品中的方解石卷曲。当SS/TETS比例等于或大于45:45时，样品中出现Ca(OH)₂的衍射峰。未添加TETS的样品中仅观察到Ca(OH)₂的衍射峰以及方解石和C-S-H的弱衍射峰，但没有碳铝酸钙的衍射峰。90天时强度仅为4.92MPa。硬化浆体强度的提高与添加TETS后新相的生成密切相关。由于C-S-H的水化作用，硬化浆体中的固体颗粒被胶结在一起。方解石形成硬化浆体的骨架，而碳铝酸钙填充硬化浆体颗粒间的孔隙，从而使其更加致密。因此，强度增加。
