| 摘要 |
The invention relates to a process for reducing the halogen content of a particulate polyolefin prepared by catalytic polymerisation of an olefin in the presence of a Ziegler-Natta catalyst. In this process, the polyolefin in the dry state is passed through a gas-fluidised bed, during which the polyolefin in the fluidised bed is brought into contact with gas containing from 0.05 to 2.0% of alkylene oxide, from 5 to 30% of water and the remainder of an inert gas. During this process, the alkylene oxide reacts with the halogen present in the polyolefin, forming an alkylene halohydrin. The alkylene halohydrin is removed from the fluidised bed, reducing the halogen content of the polyolefin. The improvement is that the alkylene oxide is regenerated by bringing the inert gas containing the alkylene halohydrin into contact with an alkali solution in alcohol or water, and then recovering the alkylene oxide formed by reaction of the alkyl halohydrin and the alkali solution.
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