| abstract |
Polymerization catalyst consisting essentially of treated silica support and zerovalent chromium compound is provided, as well as process for preparation and polymerization process with the invention catalyst. Silica treatment involves contacting a predominantly silica-containing support with at least one compound selected from the group consisting of Group IIA oxide or compounds convertible to the oxide form, a Group VA or VB oxide or compounds convertible to the oxide form or sulfuric acid, and calcining prior to contacting the treated support with a zerovalent chromium compound, thereby producing an active polymerization catalyst. |