【摘要】 为解决承德地区铁尾矿资源丰富但利用率低的问题，考察了单一磁铁矿尾矿砂作为建筑用砂的可行性。将磁铁矿尾矿砂以20%、40%、60%、80%、100%不同比例替代标准砂制备水泥砂浆，分析了其物相组成、微观形貌及力学性能。结果表明，当磁铁矿尾矿砂替代比例为40%时，水泥砂浆的力学性能最优，28 d平均抗折强度达17.78 MPa，平均抗压强度达81.10 MPa。扫描电子显微镜分析显示，40%替代比例的水泥砂浆试样内部水化产物分布均匀，表现出良好的微观结构。然而，过高的替代比例会抑制水化反应，降低砂浆性能。研究还发现，7～14 d的强度增长较快，之后增速放缓。研究结果为铁尾矿在建筑材料中的应用提供了科学依据，不仅有助于环境保护和资源循环利用，还为固废资源化和可持续建设提供了技术支持。更多还原

【Abstract】 In order to solve the problem of abundant iron tailings resources but low utilization rate in Chengde area,the feasibility of using single magnetite tailings sand as construction sand is investigated.Cement mortar is prepared by replacing standard sand with magnetite tailings sand in different proportions of20%,40%,60%,80%,100%,and its phase composition,microstructure and mechanical properties are analyzed.The results show that when the replacement ratio of magnetite tailings sand is 40%,the mechanical properties of cement mortar are the best,the average flexural strength of 28 d is 17.78 MPa,and the average compressive strength is 81.10 MPa.Scanning electron microscope analysis showed that the internal hydration products of cement mortar samples with 40%substitution ratio are evenly distributed and showed good microstructure.However,too high substitution ratio will inhibit the hydration reaction and reduce the performance of mortar.The study also found that the intensity of 7～14 d increased rapidly,and then the growth rate slowed down.The research results provide a scientific basis for the application of iron tailings in building materials,which not only contributes to environmental protection and resource recycling,but also provides technical support for sustainable construction.更多还原