| 摘要 |
<p>The invention relates to processes and apparatus for the elutriation of particles of a Ziegler-Natta type alpha-olefin polymerisation catalyst, based on transition metal compound(s) and preferably also comprising magnesium compounds, by means of an elutriation liquid which is a non-polar liquid, for example a hydrocarbon chemically inert in relation to the catalyst. A preferred process comprises the following stages:
<UnorderedLists id="ula01" listStyle="none"><ListItem>- preparation of a homogeneous suspension of the catalyst in the elutriation liquid. and</ListItem><ListItem>- elutriation of the catalyst by means of the suspension and the elutriation liquid in one or two elutriation columns (F1),(F2), separating the large and fine catalyst particles respectively.</ListItem></UnorderedLists></p><p>The apparatus comprises a tank (M2) for the preparation of the catalyst suspension and the elutriation column or columns (F1)(F2).</p><p>The invention also relates to elutriation of Ziegler-Natta catalyst particles using a non-polar elutriation liquid and wherein a special polar aprotic additive is employed, for example an organo-metallic compound.</p> |
