Polymerization process

Claim 1

IN A MASS POLYMERIZATION PROCESS WHEREIN LIQUID PROPYLENE IS CONTACTED WITH A CATALYST COMPRISING AN ORGANOMETAL COMPOUND AND A METAL SALT UNDER POLYMERIZATION CONDITIONS SO AS TO FORM SOLID POLYMER IN PARTICLE FORM AND WHEREIN AN EFFLUENT CONTAINING SOLID POLYMER, CATALYST RESIDUES AND LIQUID PROPYLENE IS RECOVERED FROM SAID POLYMERIZATION, THE STEPS WHICH COMPRISE: INTRODUCING SAID EFFLUENT INTO A TREATING ZONE AND MIXING CONDITIONS SUCH THAT PROPYLENE REMAINS IN THE LIQUID PHASE, WITHDRAWING THE THUS-TREATED EFFLUENT FROM SAID TREATING ZONE AND INTRODUCING SAID TREATED EFFLUENT INTO AN LIQUID PHASE, UPPER PORTION OF A WASH-ZONE, INTRODUCING A WASH LIQUID CONSISTING ESSENTIALLY OF LIQUID PROPYLENE POLYMERIZATION FEED INTO A LOWER PORTION OF SAID WASH ZONE, SAID FEED INCLUDING FRESH AND RECYCLE PROPYLENE WHEREBY ALL POLYMERIZATION FEED IS FIRST CONTACTED WITH THE TREATED EFFLUENT CONTANING CATALYST RESIDUES SO AS TO RENDER INNOCUOUS CATALYST POISONS PRESENT IN SAID FEED AND WHEREBY SAID FEED EXTRACTS AT LEAST A PORTION OF SOLUBLE MATERIALS FROM SAID EFFLUENT, CONTACTING SAID TREATED EFFLUENT WITH SAID LIQUID PROPYLENE IN SAID WASH ZONE IN COUNTERCURRENT FLOW UNDER CONDITIONS SUCH THAY SAID PROPYLENE REMAINS IN THE LIQUID PHASE, WITHDRAWING FROM AN UPPER PORTION OF SAID WASH ZONE A STREAM COMPRISING PROPYLENE, SOLUBLE POLYMER, AND CATALYST RESIDUES AND SUBJECTING SAID STREAM TO FRACTIONATION CONDITIONS TO EFFECT SEPARATION OF PROPYLENE FROM SOLUBLE POLYMER AND CATALYST RESIDUES THEREIN, RECYCLING SAID RECOVERED PROPYLENE FROM SAID FRACTIONATION ZONE TO SAID WASH ZONE AS THE SOURCE OF WASH FLUID AND TO SAID POLYMERIZATION AS THE SOLE SOURCE OF MONOMER AND DILUENT, AND RECOVERING FROM A LOWER PORTION OF SAID WASH ZONE A SLURRY STREAM COMPRISING PROPYLENE AND SOLID POLYMER SUBSTANTIALLY FREE OF CATALYST RESIDUES.