直接采用化学法,在一定工艺处理后物料产生自胶合作用,而无需再添加胶黏剂即可生产成型颗粒活性炭。采用正交试验法优化磷酸活化法制备颗粒活性炭的工艺条件。结果表明,磷酸法制备颗粒活性炭的关键是选择合适的浸渍比以及产生塑化的捏合温度,这样有利于物料产生自胶合作用以及产品强度的提高。另外,影响颗粒活性炭碘吸附值最大的因素是磷酸质量分数,影响颗粒活性炭亚甲蓝吸附值及强度最大的因素是浸渍比。在磷酸质量分数为60%,浸渍比为100%,捏合温度为170℃,捏合时间为60min的最优条件下可制得碘吸附值为1004.15mg/g,亚甲基蓝吸附值为172.5mg/g,强度为93.6%,比表面积为1694.150m2/g的颗粒活性炭。
This article is aimed to introduce a renovated method preparing granular activated carbon by phosphoric acid activation initiated by the given authors. As is known, granular activated carbon is known for its excellent adsorption abilities. They were usually prepared with a chemical method with no need to add any additives. After a certain process, wooden materials would soon become plasticized to take on a certain shape for its nature of self-bonding effect. As a result, it is easy for the granular activated carbon to be made with a large specific surface area and nice adsorption properties. It is also known that the conditions for preparing granular activated carbon can be had from the sawdust 'along with the phosphoric acid activation. The operation conditions in terms of the operation parameters, such as concentration of phosphoric acid, impregnation ratio of reactive agent to dried material (weight basis), temperature and time of kneading on the adsorption properties of granular activated carbons, can be optimized by measuring and analyzing them. The experimental results we have gained show that under the experimental conditions, it is of primary significance to pretreat the mixture in proper impregnation proportions and then to make them plasticized at proper temperature in order to improve the strength of granular activated carbon ; and the concentration of phosphoric acid. It is also necessary to know the Io- dine amount added, the impregnation ratio effects on the discoloration capacity of methylene blue and abrasive resistance. Besides, since the impregnation ratio is the key factor in chemical activation with phosphoric acid, experimental materials should be well chosen to improve the self-bonding effect. Under optim; conditions of concentra- tion of phosphoric acid (60%), impgation ratio (100%), temperature of kneading ( 170 ℃ ) in kneading of 60 min, the obtained activated granuls should be as follows: Iodiae number 1 004.15 mg/g, methylene blue adsorption 172.5 mg/ g,