摘要
钢铁生产过程中会产生大量的CO_(2)及高炉矿渣等固体废弃物,针对固废堆存及温室气体排放问题,利用矿渣矿化封存CO_(2)并充填至采空区,可有效控制岩层移动,减少地表塌陷。为了保证封存方法的可行性,文中在常温常压条件下,利用X射线衍射、电子显微镜?X射线光电子能谱和热重分析等方法,研究了矿渣基固废固碳充填材料(SCFM)的力学性能及微观结构和物相组成,并分析了SCFM的CO_(2)固化和强度强化机理。在制备SCFM过程中,硅酸盐水泥、熟石灰和矿渣粉先发生水化反应,水化产物(水化硅酸钙凝胶和氢氧化钙)再与CO_(2)进行碳化反应生成硅胶(gel)和碳酸钙。结果表明,SCFM强度随硅酸盐水泥和熟石灰掺量的增加而提高,水泥和熟石灰掺量分别为20%和7%时的SCFM试样强度最大,3 d和28 d强度分别达到4.41 MPa和16.47 MPa。1 g SCFM的CO_(2)最大封存量为1.83 mg,与水泥和熟石灰掺量成正比,熟石灰为最大影响因素。SCFM提高了固废利用率和CO_(2)利用封存率,为实现“双碳”战略目标提供了一定的理论支持。
Iron and steel production processes generate a large amount of CO_(2) and solid wastes such as blast furnace slag.Slag mineralization for CO_(2) sequestration and its injection into goaf was proposed to solve the problems of solid waste accumulation and greenhouse gas emission,which can effectively control the movement of rock layers and reduce ground surface collapse.This research investigated the mechanical properties,microstructure and phase composition of the slag-based carbon filling material(SCFM)using X-ray diffraction(XRD),scanning electron microscopy(SEM)、X-ray photoelectron spectroscopy(EDS)and thermogravimetric analysis(TG)under ambient temperature and pressure.The mechanism of CO_(2) curing and UCS strengthening of SCFM were analyzed.During SCFM preparation,silicate cement,slaked lime and slag powder were first hydrated,and the hydration products(hydrated calcium silicate gel and calcium hydroxide)were then carbonized with CO_(2) to produce silica gel and calcium carbonate.The results show that the strength of SCFM increased with the increase of silicate cement and slaked lime dosages,and the strength of SCFM specimens was the greatest with cement and slaked lime dosages of 20%and 7%,respectively.The strengths reached 4.41 and 16.47 MPa at the 3 d and 28 d,respectively.The maximum CO_(2) sequestration of 1g SCFM is 1.83 mg,which is proportional to the dosage of cement and slaked lime,and slaked lime is the controlling factor.SCFM improves solid waste and CO_(2) utilization and sequestration rate,which provides theoretical supports for realizing the goal of the″double carbon″strategy.
作者
丁凡煜
孙伟
张盛友
张攀科
文瑶
蔡发雄
朱艾伦
DING Fanyu;SUN Wei;ZHANG Shengyou;ZHANG Panke;WEN Yao;CAI Faxiong;ZHU Ailun(Faculty of Land Resource Engineering of Kunming University of Science and Technology,Kunming 650093,China)
出处
《高校化学工程学报》
北大核心
2025年第1期157-166,共10页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(52474131,42467022)。
关键词
碳中和
CO_(2)矿化
高炉粒化矿渣
固碳充填材料
微观形貌
carbon neutrality
CO_(2) mineralization
blast furnace slag
carbon filling materials
microscopic morphology
