高碳细灰碱活化制备活性炭的研究

Study on preparation of activated carbon from high carbon fine ash by alkali activation

高碳细灰碳含量高、具有一定孔结构,但孔隙特征参数不理想,不利于其吸附价值的利用,为此以高碳细灰为原料,采用KOH进行高温碱活化处理,通过热重(TGA)、低温氮气吸附(BET)、扫描电子显微镜-能谱(SEM-EDS)及X射线衍射(XRD)研究了高碳细灰活化反应过程及微观组成的变化。结果表明:KOH活化使高碳细灰的比表面积由477.50 m^(2)/g增加至824.37 m^(2)/g,细灰中原有的孔结构坍塌、碳骨架结构破裂,增加了微孔结构,改变了高碳细灰中灰组分的赋存状态及化学特性,并使灰分包覆于多孔炭颗粒表面,易溶于酸。

The high carbon fine ash has high carbon content and certain pore structure,but different from the pore characteristic parameters of activated carbon,and it is not conducive to the utilization of its adsorption value.Therefore,relevant research had been conducted.High temperature alkali activation treatment was carried out on high carbon fine ash using KOH.The activation reaction process and the change of its micro-composition were investigated by thermogravimetric analysis,low-temperature nitrogen adsorption,scanning electron microscopy energy dispersive analysis and X-ray diffraction.The results showed that through KOH activation,the specific surface area of high carbon fine ash increased from 477.50 m^(2)/g to 824.37 m^(2)/g.The original pore structure in the fine ash collapsed and the carbon skeleton structure broke,and the microporous structure increased.The existing state and chemical properties of ash components in high carbon fine ash were changed.Moreover,the ash was coated on the surface of porous carbon particles,which was easily soluble in acid.