摘要
为实现煤气化渣资源化利用,以煤气化渣为主要原料,高盐废水作拌合水,辅以Ca(OH)_(2)和NaOH制备出免蒸压加气混凝土。前期用正交试验和单因素试验方式,制备煤气化渣基胶凝材料。选取强度最高配比作为加气混凝土基体材料配比。主要研究双氧水和硬脂酸钙对加气混凝土物理力学性能及孔结构影响,并用XRD及SEM等微观检测方法分析不同养护温度加气混凝土的水化产物。结果表明:以煤气化渣的质量基准,外掺入占煤气化渣总量10%的NaOH、10%的Ca(OH)_(2),拌合水为高盐废水,煤气化渣基胶凝材料28 d抗压强度最高,达68.8 MPa。此外,向该胶凝材料中掺入双氧水作发气剂、硬脂酸钙作稳泡剂,制备出免蒸压加气混凝土。随双氧水掺量增加,加气混凝的孔径逐渐增大,连通孔增多,故干密度和强度一同降低。加入适量硬脂酸钙后,孔分布更均匀且孔的形态趋于规则的圆形,故强度明显提升。当双氧水和硬脂酸钙的掺量分别为5%、1.5%,养护温度80℃时加气混凝土的抗压强度最高,达2.9 MPa,对应干密度617.2 kg/m^(3)。微观分析表明:高掺量煤气化渣基加气混凝土的水化产物主要为C-S-H凝胶、C-A-H凝胶和沸石。孔壁处主要为相互交错重叠的箔片状C-S-H凝胶,存在少量杂乱交织的细长针棒状C-S-H凝胶。这些水化产物相互交联,使孔壁结构较为密实,利于强度的提高。
To realize the resource utilization of Coal gasification slag,aerated concrete is prepared with coal gasification slag as the main raw material,high salt wastewater as mixing water,supplemented by Ca(OH)_(2) and NaOH.In the early stage,the coal gasification slag based cementitious materials were prepared by orthogonal test and single factor test.The proportion with the highest strength as the propor-tion of the aerated concrete matrix material was selected.The effects of hydrogen peroxide and Calcium stearate on the physical and me-chanical properties and pore structure of aerated concrete were mainly studied,and the hydration products of aerated concrete under differ-ent curing temperatures were analyzed by microscopic detection methods such as XRD and SEM.The results show that based on the quality standard of coal gasification slag,10%NaOH and 10%Ca(OH)_(2) are added externally to the total amount of coal gasification slag,and the mixed water is high salt wastewater.At this point,the 28-day compressive strength of the coal gasification slag based cementitious ma-terial is the highest,reaching 68.8 MPa.Non-autoclaved aerated concrete is prepared by adding hydrogen peroxide as an air entraining agent and calcium stearate as a foam stabilizer to the cementitious material.As the content of hydrogen peroxide increases,the pore size of aerated concrete gradually increases and the number of connected pores increases,resulting in a decrease in both dry density and strength.After adding an appropriate content of calcium stearate,the pore distribution becomes more uniform and the pore shape tends towards a regular circular shape,resulting in a significant increase in strength.The content of hydrogen peroxide and Calcium stearate is 5%and 1.5%respectively,and the compressive strength of aerated concrete is the highest when the curing temperature is 80℃,reaching 2.9 MPa.In addition,the corresponding dry density is 617.2 kg/m^(3).Micro analysis shows that the hydration products of high content coal gasification slag based aerated concrete are mainly C-S-H gel,C-A-H gel and zeolite.The hole wall is mainly composed of foil shaped C-S-H that intersects and overlaps with each other,with a small amount of randomly interwoven slender needle shaped C-S-H.These hydration products are cross-linked with each other,making the pore wall structure denser and contributing to the improvement of strength.
作者
李颖
李辉
吴锋
李肽脂
LI Ying;LI Hui;WU Feng;LI Taizhi(College of Materials Science and Engineering,Xi′an University of Architecture and Technology,Xi′an710055,China;Shaanxi Provincial Ecological Cement Concrete Engineering Technology Research Center,Xi′an710055,China;Xinjiang Transportation Science Research Institute Co.,Ltd,Urumqi830000,China)
出处
《洁净煤技术》
CAS
CSCD
北大核心
2024年第7期154-161,共8页
Clean Coal Technology
关键词
煤气化渣
免蒸压加气混凝土
双氧水
硬脂酸钙
养护温度
coal gasification slag
non autoclaved aerated concrete
hydrogen peroxide
calcium stearate
curing temperature
作者简介
李颖(1999-),女,陕西安康人,硕士研究生。E-mail:liyingly21@xauat.edu.cn;通讯作者:李辉(1971-),女,河南三门峡人,教授,博士。E-mail:sunshine_lihui@126.com。
