A method for separating chlorides from high chlorides

Abstract

The invention discloses a method for separating chloride from perchloride. The method comprises the main following steps that 1, perchloride waste is added into an evaporator, evaporated liquid chloride is rectified, and carbon tetrachloride and tetrachloroethylene are separated out; 2, residual liquid evaporated in the first step is transferred into a sublimation kettle, water is added for heating to boiling, and meanwhile hot nitrogen is introduced in; 3, hexachloroethane sublimated in the second step is introduced into a trichloromethane dissolving tank for dissolution; 4, hot filtration is performed on the mixture obtained in the third step, the filtrate is cooled and crystallized, centrifugal separation is performed, crystals are dried to obtain a hexachloroethane product; 5, tetrachloroethylene is added into a residue in the second step to be heated and dissolved, hot filtration is performed, the filtrate is cooled and crystallized, and centrifugal separation is performed to obtain a hexachlorobenzene crude product. According to the method, hexachlorobenzene in perchloride organic risk waste is separated out, in addition, the purity of the separated hexachloroethane can be improved, and therefore the quality of the separated hexachloroethane is improved.

Description

technical field [0001] The invention relates to the field of organic chemistry, in particular to a method for separating chlorides from high chlorides. Background technique [0002] In the process of producing methane chloride and tetrachlorethylene, a certain amount of high-chloride organic hazardous waste will be produced after chlorination and distillation purification. After testing, high-chloride organic hazardous waste is a mixture of organic compounds containing various chlorides. High-chloride organic hazardous waste contains chloroform, carbon tetrachloride 2-5%, and tetrachlorethylene 40-45%. , 40-45% of hexachloroethane, 5-8% of hexachlorobenzene and 2-5% of tar, carbon black, and mechanical impurities. [0003] Patent Publication No. CN103787823A's "Method for Recovering Organic Chlorides from Distillation Residues of Methane Chlorides or / and Tetrachlorethylene" discloses a method for processing rectification residues, which can be obtained from Trichloromethan...

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Problems solved by technology

[0007] Although the above-mentioned patents can process high-chlorinated organic hazardous wastes, they still have the following disadvantages: 1. Hexachlorobenzene cannot be separated from high-chlorinated organic hazardous wastes, and can only be burned or discharged as waste. Hexachlorobenzene has acute Toxicity, teratogenicity, mutagenicity and carcinogenicity, and high-temperature decomposition produces toxic and corrosive fumes. If it is directly incinerated or discharged, it will be very harmful to the environment and human health; 2. Put the residue in the evaporator while it is hot Transfer to the sublimator, during the sublimation process, the temperature in the sublimation tank is difficult to control, and the impurities in the residue will also be sublimated together with the hexachloroethane, which will affect the purity of the separated hexachloroethane

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