煤基压块活性炭的制备及吸附水溶液中Cr(Ⅵ)的能力研究

Preparation of coal-based briquetted and crushed activated carbon and its ability to adsorb Cr(Ⅵ)from aqueous solutions

为了降低压块活性炭的制备成本,以大同不黏煤为主料,桃山焦煤和重相沥青为黏结成分,以高温煤焦油和水为成型助剂制备压块活性炭。依靠调节配煤比例和改变活化条件来调控活性炭孔结构。利用碘吸附值、亚甲蓝吸附值、耐磨强度等表征活性炭常规性能;研究了样品吸附水溶液中Cr(Ⅵ)的能力,并考察了活性炭再生效率和质量损耗情况。结果表明:在大同不黏煤、桃山焦煤、重相沥青、高温煤焦油和水的配比为51∶24∶9∶7∶9的基础上,活化温度和时间分别为875℃和2.5 h的条件下制备出的压块活性炭性能最优,其耐磨强度为90%,碘吸附值为902 mg/g,亚甲基蓝吸附值为270 mg/g,比表面积为992.6 m^(2)/g;对水溶液中Cr(Ⅵ)最大吸附容量可达27.3 mg/g;质量分数为5%的硝酸溶液对饱和活性炭在50℃条件下再生8 h效果最佳,再生5次以后,其质量损耗率为21%,性能恢复率为70.06%。

In order to reduce the preparation cost of briquetted activated carbon,briquetted activated carbon was prepared using Datong non-coking coal as the main raw materials,Taoshan coking coal and heavy-phase coal pitch as the binder components,and high-temperature coal tar and water as the molding additives.The pore structure of the activated carbon was regulated by adjusting the ratio of coal blending and changing the activation conditions.The samples were characterized using iodine adsorption value,methylene blue adsorption value,and abrasion strength;the ability of the samples to adsorb Cr(Ⅵ)from aqueous solution was investigated,and the regeneration efficiency of the activated carbon and mass loss were examined.The results showed that the briquetted activated carbon prepared based on Datong non-stick coal,Taoshan coking coal,heavy-phase bitumen,high-temperature coal tar and water in the ratios of 51∶24∶9∶7∶9,and activation temperatures and times of 875℃and 2.5 hours,respectively,had the best performance,with an abrasion resistance of 90%,an iodine adsorption value of 902 mg/g,a methylene blue adsorption value of 270 mg/g,and a specific surface area of 992.6 m^(2)/g;the maximum adsorption capacity of Cr(Ⅵ)in aqueous solution could reach 27.3 mg/g;the regeneration of saturated activated carbon with 5%nitric acid solution at 50℃for 8 h achieved the best effect,and after 5 regenerations,the mass loss rate was 21%,and the performance recovery rate was 70.06%.