High activity solid catalyst for producing low-, medium-, and high-density polyethylenes by slurry phase polymerization, process for preparing the same and use of the same in ethylene polymerization

Abstract

Disclosed is a high activity solid catalyst for synthesizing low-, medium- and high-density polyethylenes by a slurry phase process, prepared by using commercial powered magnesium as raw material, forming a magnesium halide in the nascent state, followed by successively treating said magnesium halide with an alcohol compound and an alkyl aluminum compound, then reacting the resulting suspension of the spheroidal, porous solid complex carrier with a titanium compound in the presence of an electron donor compound an alkyl aluminum compound to obtain a main catalyst component and finally mixing the catalyst component with an organometallic compound as cocatalyst. The catalyst according to the present invention is characterized by a simple preparation procedure, high polymerization activity, high sensitivity to the modification by hydrogen, high copolymerization power and smooth and stable polymerization reaction when used for slurry phase polymerizing ethylene, and the products thus obtained have good particle morphology.