摘要
提出了一种新的基于直接冷却固化与发汗提纯的熔融结晶技术。其基本过程是将有机混合物熔融液直接滴入惰性冷却介质中,制成大小均匀的固体颗粒,然后经发汗、分离发汗液后,得到高纯度产品。实验研究了原料组成、冷却固化温度、固体颗粒直径等因素对颗粒提纯效果的影响。结果表明,原料组成不同的固体颗粒在相同温度下发汗提纯,其产品纯度趋向一致,说明产品的最终纯度是由发汗温度决定的。冷却固化温度低,得到的固体颗粒结构致密,颗粒发汗提纯速率较慢,但产品收率较高。颗粒直径越小,提纯速率越快,发汗后产品纯度也越高。以对二氯苯含量为85%的混合二氯苯为原料,在0℃冷却固化制成直径为3 1mm的固体颗粒,经100min发汗处理后,对二氯苯含量提高到99 6%,发汗提纯速率常数为1 02×10-3s-1。
This paper presents a new type of melt crystallization technique based on a combination of solidification and sweating. In the new melt crystallization process,the organic molten material was directly injected into the cooling medium and solidified to form frozen droplets of uniform size.Then the droplets were sweated and separated from the sweat liquor,and the product with high purity was obtained.The effects of material composition,cooling medium temperature and diameter of the frozen droplets on the product purity and yield were studied.Experimental results showed that the purity of the frozen droplets of different initial compositions tend towards the same value at the same sweating temperature,which indicates that the purity of the frozen droplets are determined by the sweating temperature.At lower solidification temperature,the structure of the frozen droplets is more compact,and the purification rate by sweating is slower,however the yield is higher.When the frozen droplets are smaller,the purification rate is faster,and the product is purer.Under the conditions of material composition of p-dichlorobenzene 85%,cooling medium temperature 0℃,diameter of frozen droplets 3.1mm and sweating time 100min,the purity of frozen droplets could be enhanced up to 99.6% in one step.The purification rate coefficient is 1.02×10^(-3)s^(-1).
出处
《江苏工业学院学报》
2004年第2期33-36,共4页
Journal of Jiangsu Polytechnic University
基金
江苏省自然科学基金资助(BK2002011)
关键词
熔融结晶
直接冷却
固化
发汗
颗粒提纯
melt crystallization
direct cooling
solidification
sweating
pastille purification
