Liu Xinyue, Wu Pengfei, Liu Xiaoming, Zhang Zengqi, Ai Xianbin
State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China.
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel). 2024 Sep 18;17(18):4574. doi: 10.3390/ma17184574.
Carbon emission reduction and steel slag (SS) treatment are challenges in the steel industry. The accelerated carbonation of SS and carbonated steel slag (CSS) as a supplementary cementitious material (SCM) in cement can achieve both large-scale utilization of SS and CO emission reduction, which is conducive to low-carbon sustainable development. This paper presents the utilization status of CSS. The accelerated carbonation route and its effects on the properties of CSS are described. The carbonation reaction of SS leads to a decrease in the average density, an increase in the specific surface area, a refinement of the pore structure, and the precipitation of different forms of calcium carbonate on the CSS surface. Carbonation can increase the specific surface area of CSS by about 24-80%. The literature review revealed that the CO uptake of CSS is 2-27 g/100 g SS. The effects of using CSS as an SCM in cement on the mechanical properties, workability, volume stability, durability, environmental performance, hydration kinetics, and microstructure of the materials are also analyzed and evaluated. Under certain conditions, CSS has a positive effect on cement hydration, which can improve the mechanical properties, workability, bulk stability, and sulfate resistance of SS cement mortar. Meanwhile, SS carbonation inhibits the leaching of heavy metal ions from the solid matrix. The application of CSS mainly focuses on material strength, with less attention being given to durability and environmental performance. The challenges and prospects for the large-scale utilization of CSS in the cement and concrete industry are described.
减少碳排放和钢渣（SS）处理是钢铁行业面临的挑战。钢渣的加速碳酸化以及将碳酸化钢渣（CSS）作为水泥中的辅助胶凝材料（SCM），既能实现钢渣的大规模利用，又能减少二氧化碳排放，有利于低碳可持续发展。本文介绍了碳酸化钢渣的利用现状。描述了加速碳酸化途径及其对碳酸化钢渣性能的影响。钢渣的碳酸化反应导致平均密度降低、比表面积增加、孔隙结构细化以及不同形态碳酸钙在碳酸化钢渣表面沉淀。碳酸化可使碳酸化钢渣的比表面积增加约24 - 80%。文献综述表明，碳酸化钢渣的二氧化碳吸收量为2 - 27 g/100 g钢渣。还分析和评估了在水泥中使用碳酸化钢渣作为辅助胶凝材料对材料的力学性能、工作性、体积稳定性、耐久性、环境性能、水化动力学和微观结构的影响。在一定条件下，碳酸化钢渣对水泥水化有积极作用，可提高钢渣水泥砂浆的力学性能、工作性、体积稳定性和抗硫酸盐性。同时，钢渣碳酸化抑制了重金属离子从固体基质中的浸出。碳酸化钢渣的应用主要集中在材料强度方面，对耐久性和环境性能的关注较少。描述了碳酸化钢渣在水泥和混凝土行业大规模利用面临的挑战和前景。
