金属阳离子对氯氧镁水泥耐水性的影响  

Effect of Metal Cation on Water Resistance of Magnesium Oxychloride Cement

作　　者：高鹤天 陈啸洋 余红发[4] 关岩 毕万利[3,5] 李晶 GAO Hetian;CHEN Xiaoyang;YU Hongfa;GUAN Yan;BI Wanli;LI Jing(School of Civil Engineering,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China;School of Chemical Engineering,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China;School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China;Department of Civil Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Research Institution of Keda Fengchi Magnesium Building Materials,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China)

机构地区：[1]辽宁科技大学土木工程学院,辽宁鞍山114051 [2]辽宁科技大学化工学院,辽宁鞍山114051 [3]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [4]南京航空航天大学土木工程系,南京210016 [5]辽宁科技大学科大峰驰镁建材研究院,辽宁鞍山114051

出　　处：《硅酸盐学报》2022年第11期2826-2833,共8页Journal of The Chinese Ceramic Society

基　　金：国家重点研发计划子课题(2020YFC1909304);国家自然科学基金面上项目(51778101)。

摘　　要：氯氧镁水泥(MOC)具有质轻早强、导热系数低、耐火等优势,但耐水性差限制了其在土木、建筑等工程的应用。为了提高MOC耐水性,以含不同金属阳离子的可溶性硫酸盐作为改性剂,分析了可溶性金属阳离子对MOC凝结时间、抗压强度和耐水性的影响,探究了被改性后的MOC相组成、微观形貌和孔结构的变化规律。结果表明:Al^(3+)、Fe^(2+)、Cu^(2+)与MOC料浆中的游离OH?可优先形成沉淀,这抑制了Mg(OH)_(2)的形成,延缓MgO水化,延长了凝结时间,降低了MOC基体的总孔隙率,提高MOC的耐水性。其中,对MOC耐水性的改善效果从高到低依次为:Fe^(2+),Cu^(2+),Al^(3+),Na^(2+)。此外,SO42?可通过与5Mg(OH)_(2)·Mg Cl_(2)·8H2O中Mg^(2+)的吸附配位作用提高5Mg(OH)_(2)·MgCl_(2)·8H2O在水中的稳定性。Magnesium oxychloride cement(MOC)has some advantages like light weight,early strength,low thermal conductivity,and fire resistance,but poor water resistance restricts the application of MOC in civil,construction and other fields.This paper was to improve the water resistance of MOC by using soluble sulfates containing different metal cations as additives.The effect of soluble metal cations on the setting time and compressive strength of MOC was investigated.The phase composition,microstructure and pore structure of modified MOC were characterized by X-ray diffraction,scanning electron microscopy,and mercury intrusion porosimetry.The results show that Al^(3+),Fe^(2+),Cu^(2+)ions and free OH?ions in the MOC slurry can preferentially form a precipitate,inhibiting the formation of Mg(OH)_(2),delaying the hydration of MgO,prolonging the setting time,reducing the total porosity of the MOC matrix,and improving the water resistance of MOC.In addition,SO_(4)^(2+)ions can also improve the stability of 5Mg(OH)_(2)·Mg Cl_(2)·8H_(2)O after soaking in water through the adsorption and coordination with Mg^(2+)ions in 5Mg(OH)_(2)·Mg Cl_(2)·8H_(2)O.

关 键 词：氯氧镁水泥 可溶性硫酸盐 水化产物 耐水性 

分 类 号：TB33[一般工业技术—材料科学与工程]