Process for producing an olefin polymerization catalyst

The present invention aims to provide a process for producing an olefin polymerization catalyst comprising the steps of: (A) continuously introducing a first liquid comprising a transition metal compound, an organometallic compound of a metal of Group 13 of Periodic System of Elements and a solvent, and a second liquid which together with said first liquid is capable of forming an emulsion, into a catalyst preparation stage to produce a solid catalyst component comprising said transition metal compound and said organometallic compound; (B) continuously withdrawing a mixed stream comprising said solid catalyst component dispersed in a mixed liquid from said catalyst preparation stage; (C) dividing said mixed stream into a first product stream comprising the majority of said solid catalyst component and a liquid stream comprising mainly of said mixed liquid; (D) directing said first product stream, a monomer stream and a stream of said second liquid to a prepolymerization stage where said monomer is polymerized on said solid catalyst component; (E) continuously withdrawing a slurry stream comprising said second liquid, and prepolymerized catalyst from said prepolymerization stage; (F) dividing said slurry stream into a recyclable liquid stream comprising a majority of said second liquid and a second product stream comprising a majority of said prepolymerized catalyst; (G) recycling at least a major part of said recyclable liquid stream liquid into the catalyst preparation stage; and (H) recovering said second product stream. The process offers a simple and economical method of producing the solid catalyst component. The catalyst is active in polymerization and can be used in industrial processes.