煤沥青制备磁性活性炭的初步研究

Preliminary study on the preparation of magnetic activated carbon from medium coal tar pitch

以煤沥青为原料,通过熔融法加入磁性组分Fe_3O_4制备磁性活性炭。对加入方式、炭化和活化等因素的影响进行了探索。实验结果表明,煤沥青中加入磁性组分Fe_3O_4颗粒,会使表面积有所下降;与负载法相比,熔融法加入磁性组分的磁性活性炭比表面积提高了约900 m^2/g;炭化温度在450℃时活化时间90 min左右为宜;活化温度在800℃时活化时间90~120 min为佳。采用XRD、SEM和EDX对磁性活性炭进行了表征,制备的活性炭呈层状的片状结构,磁性组分Fe_O_4在炭化和活化过程中未发生变化,保持了磁性性能,而且铁元素分布相对比较均匀,没有发生团聚现象。因此,加入方式对活性炭的性能有重要影响,在炭化前通过熔融法加入磁性组分制备的活性炭性能优于炭化后再赋磁性的活性炭。

Magnetic activated carbon was prepared from coal tar pitch by melting method to add magnetic components Fe_3O_4.Influencing factors were studied including the addition methods,carbonization and activation process.The results showed that the surface area of activated carbon decreased when magnetic components Fe_3O_4 was added in coal tar pitch.Melting method for adding magnetic components has more advantages than load method after carbonization process,and the specific surface area of the activated carbon increased more than 900 m^2/g.The optimum conditions were obtained：carbonization temperature of about 450℃,carbonization time of about 90 min,activation temperature of about 800℃,and activation time of 90~120 min.The structure of the obtained magnetic activated carbon has been characterized by XRD,SEM and EDX.The results implied activated carbon showed a layered structure,and the magnetic component Fe_3O_4 did not change to keep the magnetic performance and iron distribution was relatively uniform.The adding method of magnetic components has great influence on the performance of the activated carbon.