摘要
为促进钒钛铁尾矿高质量、规模化地有效利用,以钒钛铁尾矿为主要原料制备复合胶凝材料,采用粒度分析、力学性能测试、X射线衍射(XRD)及扫描电镜(SEM)测试等手段,研究了钒钛铁尾矿粉磨特性、掺量对复合胶凝材料性能影响及复合胶凝材料的水化机理。结果表明:粉磨30 min的钒钛铁尾矿比表面积达到400 m^(2)/kg,其28 d活性指数接近70%;当钒钛铁尾矿掺量为27%,胶砂比为1∶3,水胶比为0.4时,所制备的复合胶凝材料3 d和28 d抗压强度分别为14.9 MPa和32.6 MPa,标准稠度为32.6%,凝结时间为125 min(初凝)和396 min(终凝),复合胶凝材料净浆试样14 d的收缩值较同龄期P·O 42.5水泥净浆试样收缩值低51.8%;在标准养护条件下,复合胶凝材料的水化产物主要为C-S-H凝胶、Ca(OH)^(2)、Mg(OH)^(2)和钙矾石(AFt),钒钛铁尾矿水化反应后残余矿物相石英和透辉石颗粒与水化产物的凝聚效应为复合胶凝材料的强度提供了保障,透辉石水化生成Mg(OH)^(2)对胶凝体系早期自收缩起到抑制作用。
In order to improve the high-quality and large-scale effective utilization of vanadium-titanium iron ore tailings(VIOTs), composite cementitious materials(CCM) were prepared with VIOTs as the main raw materials. The effects of grinding characteristics of VIOTs, content of VIOTs on the properties of CCM and hydration mechanism of CCM were investigated via means of particle size analysis,mechanical property test, X-ray diffraction(XRD) and scanning electron microscope(SEM). The results show that the specific surface area of VIOTs grinding for 30 minutes reaches 400 m^(2)/kg, and its28-day activity index is close to 70%. When the content of VIOTs is 27%, the cement-sand ratio is1∶3 and the water-binder ratio is 0.4, the 3-day and 28-day compressive strength of the CCM are 14.9MPa and 32.6 MPa respectively, the standard consistency is 32.6%, the initial setting time is 125 min and the final setting time is 396 min. The 14-day shrinkage value of CCM paste is 51.8% lower than that of P·O 42.5 cement paste at the same age. The hydration products of the CCM are mainly C-S-H gel,Ca(OH)^(2), Mg(OH)^(2)and ettringite(AFt) under standard curing conditions, and the coagulation effect of quartz and diopside particles and hydration products after the hydration reaction of vanadium-titanium iron ore tailings is the guarantee for the strength of the CCM. The hydration of diopside to form Mg(OH)^(2)can inhibit the early self-shrinkage of the cementitious system.
作者
王长龙
马锦涛
杨丰豪
张高青
陈敬亮
荊牮霖
李鑫
翟玉新
刘枫
Wang Changlong;Ma Jintao;Yang Fenghao;Zhang Gaoqing;Chen Jingliang;Jing Jianlin;Li Xin;Zhai Yuxin;Liu Feng(School of Civil Engineering,Hebei University of Engineering,Handan 056038,Hebei,China;School of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Construction Development Co.,Ltd.,China Railway Construction Group,Baoding 074207,Hebei,China)
出处
《钢铁钒钛》
CAS
北大核心
2023年第1期98-105,共8页
Iron Steel Vanadium Titanium
基金
国家重点研发计划(2018YFC1903602-01)
河北省自然科学基金(E2020402079,E2022402103)
河北省科技重大专项项目(21283804Z)
固废资源化利用与节能国家重点实验室开放基金(SWR-2020-004)
中铁建设集团有限公司科技研发计划(22-14b,22-11b)
邯郸市科学技术研究与发展计划项目(21422111260)。
关键词
钒钛铁尾矿
复合胶凝材料
掺量
透辉石
凝聚效应
vanadium-titanium iron ore tailings(VIOTs)
composite cementitious materials(CCM)
content
diopside
coagulation effect
