摘要
钢渣作为钢铁工业的主要固体废弃物,其富含的钙基矿物具有通过碳化反应实现CO_(2)固定和自身结构改性的双重潜力,对钢渣资源化利用具有重要意义。本文系统研究了常压干法条件下钢渣粉的碳化行为及其产物作为辅助胶凝材料的应用性能。采用质量增益法、热重分析法和XRD定量分析法对钢渣粉的固碳效率进行了综合评价,并结合SEM分析了碳化产物的微观形貌与结构演变。结果表明,碳化温度对固碳率影响显著,在45℃碳化温度和8 h碳化时间的优化条件下,钢渣粉表现出良好的固碳效果。碳化产物碳酸钙的晶型随碳化温度升高依次为方解石、球霰石和文石。将碳化钢渣粉应用于水泥基材料中,其碳化产物可作为异相成核位点,促进早期水化反应和水化产物形成,使碳化钢渣水泥的28 d抗压强度较未碳化组提高了31.2%,展现出优异的改性效果。
Steel slag,a major solid waste from the steel industry,is rich in Ca-bearing minerals,offering a dual potential for CO_(2) sequestration and self-modification via carbonation,which is crucial for its resource utilization.The carbonation behavior of steel slag powder under ambient pressure and dry conditions,as well as the application performance of the carbonated product as a supplementary cementitious material were systematically investigated.The carbon sequestration efficiency of steel slag powder was comprehensively evaluated by using mass gain method,thermogravimetric analysis and quantitative X-ray diffraction,and SEM was employed to analyze the microstructure and structural evolution of the carbonation products.The results show that carbonation temperature significantly affects the carbon sequestration rate,with an optimal carbonation temperature of 45℃and a carbonation time of 8 h yielding favorable CO_(2) uptake.The crystalline forms of the generated calcium carbonate are calcite,vaterite,and aragonite,sequentially,with the increase of carbonation temperature.When the carbonated steel slag powder is used in cement-based materials,the carbonation products serve as heterogeneous nucleation sites,promoting early hydration and the formation of hydration products,resulting in a 31.2%increase in the 28 d compressive strength of the carbonated steel slag cement compared with the uncarbonated group,demonstrating an excellent modification effect.
作者
张晓哲
赵计辉
李忠
李建新
ZHANG Xiaozhe;ZHAO Jihui;LI Zhong;LI Jianxin(School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China;School of Intelligent Transportation and Engineering,Guangzhou Maritime University,Guangzhou 510725,China)
出处
《武汉科技大学学报》
北大核心
2025年第2期112-120,共9页
Journal of Wuhan University of Science and Technology
基金
国家自然科学基金项目(52378280)
广东省基础与应用基础研究基金项目(2024B1515020087).
关键词
钢渣粉
碳化反应
固碳效率
评价方法
水泥性能
steel slag powder
carbonization reaction
carbon sequestration efficiency
evaluation method
cement property
作者简介
张晓哲(2000-),男,中山大学硕士生.E-mail:zhangxz20@163.com;通信作者:赵计辉(1985-),男,中山大学教授,博士生导师.E-mail:zhaojh28@mail.sysu.edu.cn。
