利用超声波从废触媒中回收活性炭的研究

RECOVERY OF ACTIVE CHARCOAL FROM WASTE CATALYST VIA ULTRASONIC WAVE

合成醋酸乙烯的触媒为载有醋酸锌的活性碳，目前工业生产过程中产生的废触媒大量堆积于某些工厂附近，造成环境问题。由于这种载体活性碳具有丰富的微孔，用重复煮沸的方法清洗醋酸锌后再活化回收的活性碳质量达不到中国林业部的标准。本文用功率超声来处理这种废触媒，用正交表安排实验，试验了作用时间、声能大小、温度、体系固液比、外加搅拌等条件的影响。结果表明，所提供的声能大小是洗脱醋酸锌的关键因素，另外，机械搅拌有利于物料的均匀分散，也是一个重要因素．在声强为０．３Ｗ／ｃｍ２，频率为２７ｋＨｚ的超声条件下，当固液比为１：２时，只需在室温的水中超声处理１５ｍｉｎ，回收大部分醋酸锌后所得的活性碳在６５０℃下活化０．５ｈ后，产品便可达到中国林业部标准ＬＹ２１６—７９的要求。由于这种方法操作简单，便于生产自动控制，可望成为一种再生利用废资源的好方法。通过对比了冷水浸提、沸水清洗和超声清洗等几种方法所得活性碳的ＤＴＡ，ＴＧ曲线，初步认为超声处理的特效性可归因于声毛细效应。

The manufacture industry of vinyl acetate produces a large amount of waste catalyst, zinc acetate supported on active charcoal. The waste catalyst occupies a lot of space in the factory and causes environmental pollution. There were a plenty of micro- pores in the charcoal, so the effort to recover the charcoal from waste catalyst by washing with hot water and activating it at high temperature was not successful. The quality of the recovered charcoal could not reach the standard of Forestry Department of China. We recovered the charcoal from the waste catalyst by using ultrasonic washing. The orthogonal table in terms of time, power, temperature and the ratio of solid to liquid etc. was used to arrage the experiment in order to reduce the time of experiment. The result showed that the intensity of ultrasonic energy was the most important factor and the mechanical stir was the secondary important factor in the removal of zinc acetate. With 27kHz and 0. 3W/cm2 ultrasonic wave irradiation, the zinc acetate was removed effectively after washing with water at the ratio of 1: 2 solid/water at ambient temperature for 15 minutes, and the quality of recovered active charcoal after calcination at 650℃ reached the standard of Forestry Department of China, LY216- 9. The method can be used in the recovery of charcoal from the waste catalyst in industrial scale. By comparig the DTA and TG curves of the active charcoal recovered via cold water immersing, hot water washing and cold water washing under ultrasonic irradiation, the effect of ultrasonic washing was thought to result from the sonocapillary phenomena.