Extraction separation method for methyl phosphine dichloride and rectification device

The invention relates to an extraction separation method for methyl phosphine dichloride and a rectification device, and belongs to the technical field of rectification separation. The extraction separation method and the rectification device solve the technical problems that in the prior art, when the methyl phosphine dichloride is separated from phosphorus trichloride, the phosphorus trichlorideis low in purity and higher in backflow. According to the extraction separation method for the methyl phosphine dichloride, an extraction agent is added into a mixture containing phosphorus trichloride and methyl phosphine dichloride, after mixing, the phosphorus trichloride and the methyl phosphine dichloride are obtained through successive distillation, and the extraction agent in residual liquid is recovered and recycled. Compared with a traditional technology, the method has the advantages that the separation efficiency is high, the number of theoretical plates is reduced, the reflux ratio is reduced, less waste