| 摘要 |
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: - preparation of a homogeneous suspension of the catalyst in the elutriation liquid, and - 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. The apparatus comprises a tank (M2) for the preparation of the catalyst suspension and the elutriation column or columns (F1), (F2). 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. |
