Extractive distillation method of hexafluorobutadiene

The invention discloses an extractive distillation method of hexafluorobutadiene, which comprises the following steps: in the presence of an extractant, performing extractive distillation on a composition containing hexafluorobutadiene and heptafluorobutene impurities, the extraction agent is selected from at least one of an organic amine compound, a nitrile compound, an ester compound, a heterocyclic compound, cycloalkane, aromatic hydrocarbon and a hexafluoropropylene copolymer; after extractive distillation, the removal rate of heptafluorobutene impurities is greater than or equal to 99%. The method has the advantages of high product purity, low equipment cost, suitability for industrial application and the like. 本发明公开了一种六氟丁二烯的萃取精馏方法，所述萃取精馏方法包括：在萃取剂存在下，对含六氟丁二烯和七氟丁烯类杂质的组合物进行萃取精馏，所述萃取剂选自有机胺类化合物、腈类化合物、酯类化合物、杂环化合物、环烷烃、芳香烃、六氟丙烯共聚体中的至少一种；经萃取精馏后，七氟丁烯类杂质的去除率≥99％。本发明具有产品纯度高、设备成本低、适于产业化应用等优点。