| 摘要 |
A process to perform the finishing of polyolefins produced by gas-phase c atalytic polymerization of one or more .alpha.-olefms in the presence of a p olymerization diluent selected from a C3-C5 alkane, wherein the polyolefm gr anules discharged from the gas-phase reactor are subjected to: (1) a first d egassing step in which said polyolefm is counter-currently contacted with a gaseous stream containing at least 85% by mol of a stripping agent selected from a C3-C5 alkane, said gaseous stream being continuously derived from the monomer recovery section of the polymerization plant; (2) a second degassin g step in which said polyolefm is counter-currently contacted with steam, th e amount of steam being from 10 to 200 Kg per 1000 kg of polyolefin.
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