高吸附性活性半焦的制备工艺研究

Study on preparation technology of high absorption activated semicoke

选用1~3mm半焦,通过硝酸预处理,并结合化学试剂KOH以及水蒸汽组合活化法,制备适宜焦化废水处理的高吸附活性半焦。通过单因素法及正交实验研究硝酸的浓度、活化时间、活化温度、碱炭比及水蒸汽流量等因素对于活性半焦吸附性能的影响,结果显示：活性半焦制备的最优工艺条件为硝酸浓度45%、水蒸汽流量0kg/h、活化温度800℃、活化时间2h、碱炭比3.0,其中碱炭比对于半焦的活化影响最大。最优条件下所制备活性半焦经检测其苯酚吸附值为280mg/g,碘吸附值为1122mg/g,亚甲基蓝吸附值为121mg/g,达到了净化水用活性炭的标准。将所制活性半焦用于焦化废水的处理,实验结果显示COD去除率为86.58%,总酚去除率为89.94%。

High absorption activated semi coke for eoking wastewater treatment were prepared by nitric acid pretreatment,combined with KOH activation and steam activation method using 1mm-3mm semicoke. Concentration of HNO3, activation time,temperature, the ratio of alkali to carbon and water vapor flow were determined by single factor and orthogonal experiment. The results showed that optimum conditions of the preparation of semicoke were 45 % HNO3 ,acti vation time of 2h, the activation temperature of 800℃ , the flow rate of water vapor 0kg/h and the ratio of alkali to semicoke 3.0. The ratio of alkali to semicoke had the greatest impact on the absorption of semicoke. Prepared under optimal condi tions semicoke had been tested and phenol benzene adsorption value of 280mg/g, iodine adsorption value of 1122mg/g, methylene blue adsorption value of 121mg/g,reached national standard of coal granular activated carbon for purifying water. The semicoke was used in coking wastewater treatment. The experimental results showed that the COD and total phenol removal efficiency were 86.58% and 89.94% respectively.