Process for extracting high-purity paradichlorobenzene by using solvent extraction method

Abstract

The invention discloses a process for extracting high-purity paradichlorobenzene by using a solvent extraction method, which comprises the following steps of: introducing paradichlorobenzene containing o-dichlorohenzene in an ethanol solvent, separating out o-dichlorohenzene crystal, conducting centrifugation by a centrifuger, separating dichlorobenzene crystal from mother solution, and obtaining paradichlorobenzene with the content higher than 99.5 percent. The process has the advantage that by using ethanol as solvent, integrating the processes of extraction, crystallization, washing, filtration and the like, utilizing the functions of ethanol solvent of selective extraction on o-dichlorohenzene and washing on crystal, and using the centrifuger to conduct centrifugal filtration on solid-liquid mixture, the problem that o-dichlorohenzene is adhered to and wrapped in the paradichlorobenzene crystal is effectively solved, and the purity and yield of the product are guaranteed.

Description

technical field [0001] The invention relates to a process for extracting high-purity p-dichlorobenzene, in particular to a process for extracting high-purity p-dichlorobenzene by a solvent extraction method that is beneficial to improving the separation effect and facilitating the subsequent purification of centrifuged mother liquor. Background technique [0002] p-dichlorobenzene is an important organic chemical raw material, as a high-efficiency civil anti-moth and mildew-proof product and an intermediate in the synthesis of pesticides, medicines, and dyes. In order to ensure the safety of use and product quality, the purity of p-dichlorobenzene is required It must be higher than 99.5%, and the content of p-dichlorobenzene separated by cooling and crystallization in our company is only about 97%. Dichlorobenzene was separated and purified again. [0003] According to the difference in the melting point of o-dichlorobenzene and p-dichlorobenzene (p-dichlorobenzene 53°C, o-...

AI Technical Summary

Problems solved by technology

However, in the process of melting and crystallization, due to the coercion and adhesion of the mother liquor on the crystal, it is difficult to obtain high-purity p-dichlorobenzene, and it is impossible to perform multi-stage melting treatment for p-dichlorobenzene with a content of about 97%.