煤田地质与勘探2025，Vol.53Issue(12)：78-87,10.DOI:10.12363/issn.1001-1986.25.05.0351
固废基充填材料CO2矿化与胶凝性能退化关联机制
Mechanisms governing CO2 mineral trapping and cementitious activity degradation of solid waste-based backfill materials
摘要
Abstract
[Objective]This study investigated three types typical alkaline industrial solid waste:steel slag,fly ash,and bottom ash,highlighting the differences in their CO2 mineral trapping efficiency and the degradation patterns of their ce-mentitious activity after carbon fixation.The purpose is to reveal the mechanisms underlying CO2 mineral trapping in solid waste and evaluate their application potential in backfill engineering,thereby promoting the synergistic develop-ment of industrial solid waste recycling and carbon emission reduction.[Methods]Through experiments on CO2 miner-al trapping using the direct wet method,the kinetics and product characteristics of solid waste-CO2 interactions were sys-tematically investigated.In combination with X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),and thermogravimetric analysis(TGA),the phase composition and microstruc-tures of the products formed during CO2 mineral trapping were characterized.Finally,the cemented backfill specimens were prepared using carbonated solid waste,and their mechanical properties,along with the evolutionary patterns of their pore structures,were compared and analyzed.[Results and Conclusions]The alkalinity reduction process during CO2 mineral trapping was governed by the content and dissolution kinetics of Ca2+.The pH values of the solutions of steel slag,fly ash,and bottom ash exhibited rapid-stable decreases,slow-rapid-stable decreases,and a sudden decrease,respectively.Under the condition of 0.3 MPa and 25℃,steel slag demonstrated the highest carbon(CO2)fixation capa-city(136.1 g/kg),significantly outperforming both fly ash(81.86 g/kg)and bottom ash(16.2 g/kg).The primary products of the solid waste included calcite CaCO3(steel slag and bottom ash)and aragonite CaCO3(fly ash).Influ-enced by the consumption of active calcium and the interfacial effect,the compressive strength of the specimens de-creased by 45.65%-73.48%after carbon fixation.Specifically,the steel slag-based specimens exhibited the highest de-creased amplitude(from 10.22 MPa to 2.71 MPa),followed by fly ash-based specimens(from 9.8 MPa to 3.61 MPa).In contrast,the bottom ash-based specimens showed a minimal decline in the compressive strength(from 7.82 MPa to 4.25 MPa)due to incomplete reactions during CO2 mineral trapping.The results of this study provide theoretical support and a technical reference for the synergy between the treatment of industrial solid waste and CO2 mineral trapping.关键词
工业固废/CO2矿化/固碳降碱/煤矿充填/胶凝活性/矿化机理Key words
industrial solid waste/CO2 mineral trapping/carbon fixation and alkalinity reduction/coal mine backfill/ce-mentitious activity/mechanisms behind CO2 mineral trapping分类
资源环境引用本文复制引用
刘志飞,陈庆庭,李宏杰,王恩,赵鹤鸣..固废基充填材料CO2矿化与胶凝性能退化关联机制[J].煤田地质与勘探,2025,53(12):78-87,10.基金项目
国家自然科学基金项目(52204138) （52204138）
煤炭科学技术研究院有限公司科技发展基金项目(2024JC-03) （2024JC-03）
