Abstract The carbonation of steel slag to produce building material is a useful way to increase the utilization of steel slag and absorb carbon dioxide. In this study, gypsum, steel slag, and water were mixed, compaction-shaped, and carbonation-cured as a means of improving the strength of the steel slag. It was observed that gypsum promoted an increase in both the compressive strength and the CO2 uptake of steel slag. CO2 uptake was positively correlated with strength. Microanalysis indicated that the main hydration product were C-S-H phases and ettringite, while the main carbonation products were calcite and monocarbonate (C3A. CaCO3.11H2O). Gypsum is speculated to promote the rapid hydration of steel slag to form ettringite (C3A.3CaSO4.32H2O), which then reacts with CO2 to produce monocarbonate; thus, gypsum plays a catalytic role in this system. The results of this study therefore provide theoretical guidance for the preparation of steel slag–gypsum carbide building materials.

中文翻译：

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建筑材料钢渣和石膏的碳化及相关反应机理

摘要 钢渣碳化生产建筑材料是提高钢渣利用率和吸收二氧化碳的有效途径。在本研究中，将石膏、钢渣和水混合、压实成型和碳化固化，作为提高钢渣强度的一种手段。据观察，石膏促进了钢渣的抗压强度和 CO2 吸收量的增加。CO2 吸收量与强度呈正相关。微量分析表明，主要水化产物为CSH相和钙矾石，而主要碳酸化产物为方解石和单碳酸盐(C3A.CaCO3.11H2O)。据推测，石膏促进钢渣快速水化形成钙矾石（C3A.3CaSO4.32H2O），然后与二氧化碳反应生成单碳酸盐；因此，石膏在该系统中起着催化作用。因此，本研究结果为钢渣-碳化石膏建材的制备提供了理论指导。