磁铁矿粉加重质的表面疏水改性  

Surface Modification of Hydrophobic Magnetite Powder

作　　者：骆振福[1] 朱建凤[1] 李振[1] 刘昆仑[1] 

机构地区：[1]中国矿业大学化工学院,江苏徐州221116

出　　处：《中国矿业大学学报》2009年第1期75-79,共5页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(90510002);国家高技术研究发展计划(863)项目(2007AA05Z318);教育部科学技术研究重大项目(306008)

摘　　要：磁铁矿粉表面呈亲水性,在气-固流化床中作为加重质用于煤炭分选时,为了使其不与含外在水分的煤黏附,必须进行表面改性.选择硬脂酸对磁铁矿粉进行表面改性,用SEM,IR和TG对改性后磁铁矿粉的形貌和结构进行表征.结果表明,硬脂酸使磁铁矿粉表面由亲水性变成疏水性,其在磁铁矿粉表面的吸附为化学吸附.温度、时间和硬脂酸的用量是影响改性效果的主要因素,其最佳改性条件为:温度60℃,时间40 min,改性剂量1.5%.改性后的磁铁矿粉粒度分布基本不变,但改性后的磁铁矿粉颗粒间摩擦力减小,有利于形成高质量的流化床.Magnetite powder is hydrophilic. To prevent its adhering to wet coal the surface of magnetite powder must be modified before it is used for coal separation in a gas-solid fluidized bed. Stearic acid was chosen as the surface modifier for magnetite powder. The morphology and structure of the magnetite powder before and after modification were characterized by SEM, IR and TG. The results show that stearic acid can change the magnetite surface from hydrophilic to hydrophobic： The adsorption of stearic acid to the magnetite surface is a chemical adsorption. The temperature, time and the dosage of stearic acid were the key factors that influenced modification efficiency. The optimal efficiency was achieved with treatment at 60 ℃, for 40 min with a dosage of 1.5%. After surface modification the size distribution of the magnetite powder is nearly unchanged but friction forces between the particles are reduced. This is propitious for formation of a good quality fluidized bed.

关 键 词：磁铁矿粉 疏水表面改性 硬脂酸 流化床 

分 类 号：TQ028.6[化学工程]