磷石膏添加量对赤泥基复合材料性能影响研究  

Effect of phosphogypsum addition on properties of red mud-phosphogypsum composites

作　　者：张建刚 皇志威 苏向东[1,2] 陈烨 李海嘉[3] 李玮 ZHANG Jiangang;HUANG Zhiwei;SU Xiangdong;CHEN Ye;LI Haijia;LI Wei(Guizhou Institute of Technology,Guiyang 550031,China;Guizhou Key Laboratory of Light Metal Material Preparation Technology,Guiyang 550031,China;School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Guizhou Zhenghe Tianzhu Technology Co.,Ltd.,Guiyang 551400,China)

机构地区：[1]贵州理工学院,贵州贵阳550031 [2]贵州省轻金属材料制备技术重点实验室,贵州贵阳550031 [3]贵州大学化学与化工学院,贵州贵阳550025 [4]贵州正和天筑科技有限公司,贵州贵阳551400

出　　处：《中国有色冶金》2023年第1期121-130,共10页China Nonferrous Metallurgy

基　　金：贵州省教育厅重点领域项目(黔教合KY字[2021]052);中央引导地方科技发展专项资金(黔科中引地[2017]4010)。

摘　　要：为促进赤泥和磷石膏两大工业固废的资源化利用,以赤泥、磷石膏和胶凝材料(包括水泥、钢渣、矿渣)为原料制备复合材料砂浆,研究了磷石膏添加量对复合材料物化性质的影响。试验结果表明,当赤泥添加量为70%,磷石膏添加量为10%时,复合材料7 d抗压强度和28 d抗压强度分别为14.97 MPa和15.2 MPa。采用XRD、SEM-EDS、TG和FTIR对复合材料矿物结构和微观形貌进行表征和分析,结果表明加入适量磷石膏可有效填充复合材料的内部结构,提高机械性能;加入过量磷石膏会形成大量的钙矾石,增大复合材料内部孔径,同时磷石膏中磷、氟成分大量富集会降低复合材料机械性能;复合材料合理配比,可固定赤泥中的钠元素,有效缓解赤泥基建筑材料的泛霜行为。对复合材料进行浸出试验,ICP-OES检测表明复合材料浸出液中重金属元素浓度满足Ⅲ类地下水排放标准,可用于工程应用。In order to promote the resource utilization of red mud and phosphogypsum industrial solid wastes,the paper uses red mud,phosphogypsum and cementing materials(including cement,steel slag and ore slag)as raw materials to prepare composite mortar.The effect of the amount of phosphogypsum added on the phenochemical properties of the composite material was investigated.The tests showed that when the red mud dosage was 70wt%,phosphogypsum dosage was 10wt%,the 7 d and 28 d compression strength of the composite were 14.97 MPa and 15.2 MPa,respectively.By the characterization and analysis of the mineral structure and micromorphology of the composite materials by XRD,SEM-EDS,TG and FTIR,it showed that the addition of an appropriate amount of phosphogypsum could effectively fill the internal structure of the composite material and improve the mechanical properties;the addition of excessive phosphogypsum could cause formation of a large amount of ettringite,thus increasing the internal aperture of the composite,at the same time,the large enrichment of components(P and F)in phosphogypsum will reduce the mechanical properties of composite materials;the composite material could fix sodium element in the red mud through properly proportioning.The leaching test of composite materials by ICP-OES showed that the concentration of heavy metal elements in the composite leaching liquid met the III groundwater discharge standard and could be used for engineering applications.

关 键 词：赤泥 复合材料 浸出 磷石膏 钙矾石 胶凝材料 钠固定 抗压强度 重金属浓度 

分 类 号：X756[环境科学与工程—环境工程]