Support for catalysts processes for the manufacture of a precursor gel for a support for catalysts and for the preparation of a support for catalysts and catalyst and process for the polymerization of olefins

摘要

Process for the manufacture of a support containing silica and at least one constituent chosen from alumina and aluminum phosphate, according to which an alcohol, water, a silicon alkoxide and an acid are mixed under conditions such that gelling or precipitation of silica is prevented, an acidic solution of an aluminum compound and/or a solution of a source of phosphate ions are added thereto, a gelling agent is added thereto, a gel is recovered which is washed with water and then by means of an organic liquid, the gel is then dried by atomization until a powder is obtained, and the powder is calcined. Polymerization of olefins in the presence of a catalyst containing chromium on a support as described above.