Polymerization of olefins

Claim 1

PROCESS FOR THE POLYMERIZATION OF ALPHA-OLEFINS WHICH COMPRISES CONTACTING, IN LIQUID PHASE UNDER POLYMERIZING CONDITIONS, AN ALPHA-OLEFIN WITH A SOLID CATALYTIC COMPOSITION COMPRISING A SUBHALIDE OF TITANIUM EXTENDED ON A SOLID CARRIER AND AN ACTIVATOR THEREFOR, DISCONTINUING SUCH CONTACTING WHEN THE ACTIVITY OF SAID COMPOSITION IS SUBSTANTIALLY DECREASED BY ADHERENCE THERETO OF POLYMERS OF SAID OLEFIN, CONTACTING THE COMPOSITION OF DECREASED ACTIVITY WITH OXYGEN AT AN ELEVATED TEMPERATURE WHEREBY POLYMER IS BURNED THEREFROM, A PORTION OF SAID POLYMER BEING CONVERTED TO CARBON WHICH REMAINS ON THE SOLID CARRIER, AND SAID SUBHALIDE OF TITANIUM IS CONVERTED TO AN OXIDE OF TITANIUM THE CARBON REMAINING ON THE CATALYST BEING FROM 1 TO 5 MOLS. PER MOL. OF TITANIUM OXIDE, CONTACTING THE RESULTING COMPOSITION COMPRISING SAID SOLID CARRIER, CARBON, AND AN OXIDE OF TITANIUM WITH CHLORINE AT AN ELEVATED TEMPERATURE WHEREBY TITANIUM TETRACHLORIDE IS EVOLVED, AND IMPREGNATING A SOLID CARRIER WITH THE EVOLVED TITANIUM TETRACHLORIDE.