花生壳粉末活性炭成型工艺研究

Study on the shaping conditions of activated carbon powder from peanut shells

本文研究了花生壳粉末活性炭的成型条件。分别采用淀粉、聚乙烯醇、羧甲基纤维素钠水溶液作为粘合剂,将粉末状花生壳活性炭粘结加压成型,制成直径5mm、高7mm的圆柱体。考察了粘合剂用量、处理温度、处理时间等因素对成型后活性炭吸附性能及机械强度的影响,并用碘的吸附值、柱状活性炭的密度及是否容易碎裂进行了表征。实验结果表明,羧甲基纤维素钠粘合剂所制得的活性炭性吸附能最好,碘附值可达900mg·g-1,聚乙烯醇粘合剂所制得的活性炭机械强度最好,碘附值在750 mg·g-1左右,淀粉粘合剂所制得的活性炭吸附能与聚乙烯醇相近,但机械强度较差,容易碎裂。处理温度和时间影响不大,以200～300℃下密闭处理60min左右为宜。聚乙烯醇适宜用量为粉末炭的10%,而羧甲基纤维素钠用量要大于粉末活性炭的5%。

The preparation conditions of a cylindrical activated carbon（AC） from the powder of peanut shell activated carbon were studied.Three kinds of binders,the aqueous solutions of polyvinyl alcohol（PVA）,sodium carboxymethylcellulose（CMC）and starch were used to make cylindrical activated carbons of φ5×7 mm.The effects of the amount of the binders,calcination temperature and time on the absorption capacity and the toughness were investigated.The experimental results showed that the shaped AC from CMC binder has the highest Indium absorption capacity,e.g.900 mg·g-1,but a little poor toughness;those from PVA binder were toughest but a little lower Indium absorption capacity,about 750 mg·g-1;those from starch binder were fragile and their absorption ability were similar to those from PVA.Calcination temperature and time affect the performances of the shaped AC unsubstantially and 200～300℃,60 min were preferred.For a good quality of shaped AC,the dosage of PVA may equal to 10 percent of that of the powder AC and the amount of CMC should overpass 5 percent of the powder AC mass.