Patent ID: 8258246

Claim:
A method for the polymerization of ethylene to provide an ethylene polymer comprising: (a) forming a supported chromium-based polymerization catalyst by supplying a particulate support material to a reactor; supplying an inert gas to the reactor entraining the particulate support material within the reactor to form a fluidized bed; introducing an aqueous solution of a chromium (III) compound to the reactor; impregnating the particulate support material with the chromium (III) compound to form a supported chromium catalyst; and activating the supported chromium catalyst by converting a predominate part of the chromium (III) on the particulate support particles to chromium (VI) to form a chromium-based polymerization catalyst; (b) providing the supported chromium-based polymerization catalyst to a polymerization reactor zone; (c) supplying a feed stream comprising an inert hydrocarbon diluent containing a minor amount of ethylene to the polymerization reaction zone; (d) incorporating said chromium-based polymerization catalyst into said feed stream within the polymerization reaction zone; (e) operating said reaction zone under polymerization conditions to produce a polyethylene polymer fluff by polymerization of said ethylene monomer; (f) withdrawing said polyethylene polymer fluff from said reaction zone; and (g) heating said polyethylene polymer fluff to a temperature sufficient to melt said fluff and thereafter extruding said heated polymer fluff to produce pellets of said polyethylene polymer.