摘要
针对冀北风沙地区交通干线附近尾矿堆积、大风吹蚀影响交通等问题,将风沙区5种不同粒径的含氯盐铁尾矿作为骨料,以水泥和工业废料矿渣、离子固化剂、氧化钙制备尾矿固化试件,探究其最优配比。基于无侧限抗压强度试验,设计6因素5水平的正交试验,从宏观角度分析固化剂、含水率、尾矿粒径对试件固化效果的影响,借助数据分析软件对其进行配比优化;结合数码显微镜(USB)、电镜扫描试验(SEM)和X射线衍射试验(XRD),从细微观角度对试件进行了固化机理分析。结果表明,影响固化试件强度最显著性的因素为颗粒粒径,其次由大到小为水泥、矿渣、氧化钙、离子固化剂、水;含氯盐尾矿固化试件最优配比为m(铁尾矿)∶m(水泥)∶m(离子固化剂)∶m(矿渣)∶m(氧化钙)∶m(水)=1∶0.12∶0.022∶0.14∶0.08∶0.10,最佳尾矿粒径范围是0.075~0.3 mm;最优配比试件28 d强度可达18.29 MPa。微观分析表明试件内部生成了大量纤维状、片状、针棒状水化产物和连续褶皱状、团簇状C—S—H凝胶体,结构致密、孔隙率低;铁尾矿砂总体活性偏低,其主要起骨架支撑和物理填充作用。固化含氯盐铁尾矿砂作为制备机械沙障的材料,与环境相容性好,具有应用价值和推广前景。
Aiming at the problems of tailings accumulation near the traffic trunk line in the wind sand disaster area in the north of Hebei Province and the impact of strong wind erosion on the traffic,the chlorine salt-iron tailings of five different particle sizes in the wind sand area were taken as aggregates,and the tailings curing test pieces were prepared with cement and industrial waste slag,ion curing agent and calcium oxide as curing agents to explore its optimal ratio.Based on the unconfined compressive strength test,the orthogonal test of 6 factors and 5 levels was designed to analyze the effects of curing agent,moisture content,and tailings particle size on the curing effect of the specimen from a macro point of view.The ratio is optimized by using data analysis software.Combined with a digital microscope(USB),scanning electron microscope(SEM)and X-ray diffraction(XRD),the curing mechanism of the specimen was analyzed from the micro point of view.The results show that the most significant factor affecting the strength of curing specimen is particle size,followed by cement,slag,calcium oxide,ion curing agent,and water.The optimal ratio of chloride tailings containing tailings curing specimen is iron tailings∶cement∶ion curing agent∶slag∶calcium oxide∶water=1∶0.12∶0.022∶0.14∶0.08∶0.10,and the optimum particle size range of tailings is 0.075 mm<d<0.3 mm.The 28 days strength of the optimal ratio test piece can reach 18.29 MPa.Microscopic analysis shows that a large number of fibrous,flaky,needle-like hydrates and continuous folded,cluster-like C—S—H gel are formed inside the specimen,with dense structure and low porosity.The overall activity of iron tailings is low,which mainly plays the role of skeleton support and physical filling.As a material for preparing mechanical sand barriers,solidified iron tailings containing chloride have good compatibility with the environment and have application value and popularization prospects.
作者
孙婧
安艳玲
王君
刘勇智
李家园
SUN Jing;AN Yan-ling;WANG Jun;LIU Yong-zhi;LI Jia-yuan(School of Civil Engineering,Hebei University of Architecture,Zhangjiakou 075000,Hebei,China;Hebei Key Laboratory for Diagnosis,Reconstruction and Anti-disaster of Civil Engineering,Zhangjiakou 075000,Hebei,China;Hebei University Road and Bridge Structure Health Monitoring and Maintenance and Reinforcement Application Technology Research and Development Center,Zhangjiakou 075000,Hebei,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2022年第5期2743-2751,共9页
Journal of Safety and Environment
基金
河北省科技厅重点研发计划项目(20373802D)
河北省建设科技研究计划项目(2020-266)。
关键词
环境工程学
含氯盐铁尾矿
固化
影响因素
配比优化
细微观结构
environmental engineering
chlorinated iron tailings
solidification
influencing factors
proportioning optimization
microstructure
