Polymerization process using catalysts with acid gelled aluminum phosphate base

Claim 1

A polymerization process comprising: contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule in a reaction zone under polymerization conditions with a catalyst produced by a process comprising: combining a source of aluminum ions with a source of phosphate ions in a concentrated mass, combining said concentrated mass with a neutralizing agent, said neutralizing agent being used in an amount insufficient to cause immediate gelation, aging until gelation occurs to form a hydrogel, removing water from said hydrogel to produce a xerogel, thereafter activating at an elevated temperature in an oxidizing ambient, and wherein 0.001 to 10 weight percent chromium or vanadium based on the weight of the xerogel is introduced prior to said activating; and recovering a polymer.