多孔煤矸石吸附剂的制备及其吸附热力学研究

Preparation and Adsorption Thermodynamics of Porous Coal Gangue Adsorbent

采用两步化学活化法对煤矸石进行处理:首先以ZnCl2为活化剂,在氦气中对煤矸石焙烧,然后用HCl蚀刻制得多孔煤矸石.利用SEM、XRD、FT-IR以及氮气吸脱-脱附仪对多孔煤矸石表征,分析了多孔煤矸石的组成、结构变化,并以罗丹明B为污染物研究了多孔煤矸石的吸附性能.结果表明,多孔煤矸石由SiO2以及少量活性炭组成;焙烧温度为600℃时,多孔煤矸石的比表面积为412.23m^2/g,平均孔径为4.9nm;对罗丹明B的平衡吸附量达到49.81mg/g,可作为水处理的吸附剂,吸附过程符合Freundlich模型,热力学分析表明多孔煤矸石吸附罗丹明B属于熵驱动型物理吸附.

Porous coal gangue adsorbent was prepared by roasting coal gangue in He with ZnCl2 as activator firstly and then etched in HCl.The SEM,XRD、FT-IR and nitrogen adsorption-desorption apparatus were employed to characterize the change of composition and structure of the prepared adsorbent,which was further applied as an effective adsorbent for rhodamine B(Rh B).The results show that the porous coal gangue consists of SiO2 and fewer activated carbon.The specific surface area and the average pore size of porous coal gangue calcined at 600℃are 412.23 m^2/g,4.9 nm and the equilibrium adsorption capacity for Rh B is 49.81 mg/g,the adsorption process can be well described by Freundlich isotherm model,thermodynamic analyses indicate that adsorption processes are entropy-driven endothermic physical adsorption process.