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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 surface is hydrophilic, as a heavier in gas-solid fluidized bed for coal sorting, in order to make it not with the external water containing coal adhesion, must be surface modified. Select stearin The surface morphology of magnetite powder was modified by acid and the morphology and structure of the modified magnetite powder were characterized by SEM, IR and TG.The results showed that the surface of magnetite powder changed from hydrophilic Hydrophobicity and its adsorption on the surface of magnetite powder is chemisorption.The temperature, time and the amount of stearic acid are the main factors affecting the modification effect.The optimum conditions for the modification are: temperature 60 ℃, time 40 min , And the modification dosage is 1.5% .The particle size distribution of the modified magnetite powder is basically unchanged, but the friction between the modified magnetite particles is reduced, which is good for the formation of high quality fluidized bed.