无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (5): 32-38.doi: 10.19964/j.issn.1006-4990.2024-0420

• 镁资源高值化利用 • 上一篇    下一篇

偏高岭土掺量对硫氧镁水泥性能的影响

乔紫璇1(), 张润丰2, 刘彤1, 付新宇1, 杨红健1()   

  1. 1.河北工业大学化工学院,天津 300401
    2.天津市津安热电有限公司,天津 300204
  • 收稿日期:2024-07-24 出版日期:2025-05-10 发布日期:2025-06-05
  • 通讯作者: 杨红健(1968— ),男,博士,副教授、硕士生导师,研究方向为无机胶凝材料、工业与建筑节能及工业与建筑废弃物资源化利用;E-mail:1991033@hebut.edu.cn
  • 作者简介:乔紫璇(2000— ),女,硕士,研究方向为无机胶凝材料;E-mail:1783213094@qq.com
  • 基金资助:
    天津市科技计划项目(18YFCZZC00200)

Effect of kaolin content on properties of magnesium oxy sulfate cement

QIAO Zixuan1(), ZHANG Runfeng2, LIU Tong1, FU Xinyu1, YANG Hongjian1()   

  1. 1. School of Chemical Engineering and Technology,Hebei University of Technology,Tianjin 300401,China
    2. Tianjin Jin'an Thermal Power Co. ,Ltd. ,Tianjin 300204,China
  • Received:2024-07-24 Published:2025-05-10 Online:2025-06-05

摘要:

硫氧镁水泥(MOSC)作为一种新型环保建材,具有早强、轻质等特点,但其强度低、耐水性差等问题限制了其广泛应用。偏高岭土(MK)是由煤系高岭土(煤矸石)煅烧而成的无定形材料,因其高火山灰活性而被广泛研究。为改善MOSC的强度与耐水性缺陷,同时实现环保节能的目标,探究了在柠檬酸质量分数为1%的改性条件下,MK掺量对MOSC性能的影响,并通过XRD和SEM分析了试样水化后的物相组成及微观结构特征,揭示了MK对MOSC的作用机理。实验结果表明,MOSC的流动度和凝结时间随MK掺量的增加而逐渐降低,而力学性能则呈现先升高后下降的趋势。从力学强度和耐水性能的角度综合考虑,MK的最佳质量分数为10%。在此掺量下,养护28 d的试样表现出最佳的抗压强度(105.77 MPa)和抗折强度(28.62 MPa),软化系数达到0.927。微观结构分析显示,掺加柠檬酸的所有样品中均出现了针棒状的517晶相同时MK的加入促进了517晶相的生长和发展,使其长径比显著增加,体系结构更加致密,从而显著提升了MOSC的力学强度和耐水性能。

关键词: 偏高岭土, 硫氧镁水泥, 改性, 力学性能

Abstract:

Magnesium oxy sulfate cement(MOSC),as a new environmentally friendly building material,has the characteristics of early strength and lightweight,but it has problems such as low strength and poor water resistance,which restricts its widespread application.Metakaolin(MK) is formed by the calcination of coal bearing kaolin(coal gangue) and exhibits high volcanic ash activity due to its amorphous structure.In order to compensate for the strength and water resistance defects of MOSC while achieving environmental protection and energy conservation,the effect of MK dosage on MOSC performance based on 1% citric acid modification was explored.XRD and SEM analysis methods were used to analyze the phase composition and microstructure characteristics of the hydrated samples,and the mechanism of MK dosage on cement samples was explained.The results showed that the flowability and setting time of MOSC were decreased with the increase of MK dosage,and the mechanical properties showed a trend of first increasing and then decreasing.From the perspective of mechanical strength and water resistance,the optimal dosage of MK was 10%.The sample cured for 28 days had the best compressive strength of 105.77 MPa and flexural strength of 28.62 MPa,and the best softening coefficient was 0.927.Needle shaped 517 crystal phase appeared in all samples doped with citric acid.The addition of MK promoted the growth and development of 517 crystal phase in the system,and the aspect ratio of 517 crystal phase increased significantly,resulting in a denser system structure.Therefore,the mechanical strength and water resistance of MOSC were significantly improved.

Key words: metakaolin, magnesium oxy sulfate cement, modification, mechanical property

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