| 摘要 |
A process for the separation of dichlorobenzene mixtures containing m- and p-dichlorobenzene by means of extractive rectification using an extracting agent is described. In the separation of the components into an m-dichlorobenzene and p-dichlorobenzene-containing fraction and the final separation of the extracting agent from one of the fractions obtained, the extracting agent used is a phosphoric ester of the general formula (I) in which R<1>, R<2 >and R<3 >are identical or different and represent an aliphatic or cycloaliphatic alkyl or alkenyl radical and R<1>, R<2 >and R<3 >together contain at least 3 and not more than 12 C atoms, or a mixture of different phosphoric esters of this type or a phosphine oxide of the general formula (II) in which R<1>, R<2 >and R<3 >are identical or different and represent an aliphatic or cycloaliphatic alkyl or alkenyl radical or hydrogen, but R<1>, R<2 >and R<3 >together contain at least 3 and not more than 12 C atoms, or a mixture of different phosphine oxides of this type or a mixture of said phosphoric esters and phosphine oxides.
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