单级结晶法从混合二氯苯中提取对二氯苯

采用减压蒸馏等方法对氯化苯精馏塔的釜底液混合二氯苯进行预处理,得到了3种不同的原料;设计了梨形夹套式搅拌萃取结晶装置,采用单级结晶法,从3种不同的原料中分别提取高纯度的对二氯苯,对比不同原料的结晶效果;由于温度是结晶过程的主要影响因素,本文重点研究了温度对结晶过程中的对二氯苯的纯度和得率的影响;实验结果表明,采用单级结晶法,选用减压蒸馏和连续精馏处理后的原料,在温度为-5°C的条件下,对二氯苯的纯度可从45.84%提高到98.79%以上,得率达到47.82%.研究结果为多级结晶法提纯对二氯苯进一步研究提供有效数据.

Refining of p-dichlorobenzene from mixtures of chlorobenzene and dichlorobenzene by single-stage crystallization

The refining of p-dichlorobenzene from the mixtures of chlorobenzane and dichlorobenzene by single-stage crystallization was put forward,the new apparatus was designed in the stLldy,and high purity of p-dichlorobenzene was obtained by this method.Three different kinds of raw materials were obtained by the raw material pretreated.Tempemmre is one of the most important influencing factor among sevelal influencing factors on the process of crystallization.So the influence of temperature was studied in detail.The results showed that the efficiency of third raw material was the best,the purity of p-dichlorobenzene could be enhanccd up to 98.79%from 45.84%,and the recovery ratio reached to 47.82%at the temperature of-5°C.Thc work provided an effective basis for the further research of refining high purlty P-dichlorobenzene by multilevel crystallization.