摘要
本工作分析了石英岩型铁尾矿机制砂中石粉的特性,考察其对砂浆与混凝土流动度的影响,建立了石粉吸附动力学方程与吸附模型,利用Zeta电位与红外测试方法,揭示了减水剂在石粉表面的吸附方式,并阐述了石粉吸附减水剂的过程与机理。结果表明,石粉中存在链状、层状、架状硅酸盐矿物成分,减水剂在矿物中存在三种吸附方式:离子键作用吸附、石粉表面的钙离子起到桥接作用吸附、表面氢键作用吸附。长石与减水剂的表面吸附最为明显。在低浓度减水剂溶液中,吸附速率满足准二级反应动力学方程,吸附速率排序为:水泥与蒸馏水>石粉与蒸馏水>石粉与水泥过滤液。石粉对减水剂的吸附为单分子吸附,符合Langmuir吸附模型,减水剂在粉体颗粒表面的最大及饱和吸附量顺序与吸附速率相反,石粉对减水剂的吸附强于水泥对减水剂的吸附,在碱性溶液中石粉吸附点活性与数量变大,导致石粉对减水剂的吸附数量增加,吸附作用力增大。
The characteristics of the sandstone powder of the quartz lithological tailings were analyzed,its influence on the fluidity of the mortar and concrete was tested,and then the adsorption kinetics equation and model of stone powder were established in this work.It reveals the adsorption method of water reducing agent on the surface of stone powder,and explains the process and mechanism of stone powder adsorbing water reducing agent using the Zeta potential and infrared test methods.The test shows that chain,layered,and frame silicate minerals exist in stone powder.There are three types of adsorption methods of water reducing agent in minerals:adsorption by ionic bonding,calcium ions on the surface of stone powder play a bridging role,hydrogen bonding on the surface,and adsorption of feldspar and water reducing agent is the main adsorption mode.In low concentration water reducing agent solution,the adsorption rate satisfies the quasi-second-order reaction kinetic equation.The order of adsorption rate is:cement and distilled water>stone powder and distilled water>stone powder and cement filter liquid.The adsorption of water reducing agent by stone powder is single-molecule adsorption,which conforms to the Langmuir adsorption model.The order of the maximum and saturated adsorption amount of water reducing agent on the surface of powder particles is opposite to the adsorption rate.The adsorption of water reducing agent by stone powder is stronger than that of cement.The activity and quantity of stone powder adsorption point in alkaline solution becomes larger,which leads to an increase in the number of stone powder adsorption to water reducer and an increase in the adsorption force.
作者
张广田
刘娟红
孔丽娟
吴瑞东
ZHANG Guangtian;LIU Juanhong;KONG Lijuan;WU Ruidong(College of Civil and Resources,University of Science and Technology Beijing,Beijing 100833,China;Hebei Academy of Building Research,Shijiazhuang 050021,China;Hebei Province Science and Technology Key Laboratory of Solid Waste for Building Materials(Preparation),Shijiazhuang 050021,China;College of Materials Science and Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050021,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第6期6071-6077,共7页
Materials Reports
基金
国家自然科学基金面上项目(51678049)
国家自然科学基金重点项目(51834001)
河北省重点研发计划(19274104D)。
关键词
石英岩型尾矿废石机制砂
石粉
吸附
减水剂
quartzite-type tailing waste rock machine-made sand
stone powder
adsorption
water reducing agent
