对二氯苯的溶析结晶分离法：溶剂组份控制

提出以水和乙醇为溶剂溶析结晶分离二氯苯混合物中的二氯苯。测定了对二氯苯在乙醇中的溶解曲线，获得了溶解不同的比例的对邻二氮苯混合物的最小乙醇加入量，并测定了ｐ－ＤＣＢ／ｏ－ＤＣＢ为７７：２３时的最大加水量。在所选条件下，溶析得到ｐ－ＤＣＢ收率为６０％－８０％，纯度在于９９．０％。

SEPARATION OF AN ISOMER MIXTURE CONTAINING ORTHO - AND PARADICHLOROBENZENE BY "SOLVENTING - OUT"PROCESSES DETERMINATION OF SOLVENTS -DETERMINATION OF SOLVENTS

The separation of the isomer mixture of dichlorobenzene(DCB) into its separate constituents (p-DCB and o-DCB) has been dealed with by using foe effect of "solventing - out"-the precipitation of p-DCB from its ethanol solution by the addition of water. The concentrations of p-DCB at different temperatures are determined. The minimum volumes of ethanol for dissolving away the iso- mer miture and the maximum volumes of water for precipitating p-DCB are measured. As to the mizture of p-DCB/o-DCB = 77 23(wt), under the suggested conditions by using the solvents, the yield of p - DCB is between 60% and 80%, and the purity of the crystal mass is over 90. 0%.