Abstract: A catalyst prepared by (1) forming a mixture of a finely divided support such as silica, alumina, zirconia or thoria and a chromium compound which may be either organic or inorganic followed by (2) adding a titanium compound, then (3) heat activating the reaction product of (2), and then (4) further heating in a gas that comprises oxygen. The disclosure also includes a method of polymerizing olefins with this catalyst and the process of preparing the catalyst.

Abstract: A method of polymerizing a monomer comprising ethylene in which a catalyst used is prepared by dispersing on a dry, finely divided, difficultly reducible inorganic oxide support such as silica a reaction product prepared by reacting pinacol with a chromium compound in which the reaction product is fixed to the support by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: A catalyst for polymerizing one or more 1-olefins prepared by activating with a dry gas that contains oxygen a mixture of a finely divided support and a tetravalent alkoxide of chromium. The disclosure also includes the method of making the catalyst and methods of polymerizing olefins with the catalyst.

Abstract: A catalyst and a method of polymerizing a monomer comprising ethylene in which the catalyst is prepared by dispersing on a dry finely divided, difficultly reducible inorganic oxide support such as silica a reaction product prepared by reacting pinacol with a chromium compound in which the reaction product is fixed to the support by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: Methods of making polymers from polymerizable 1-olefins which comprise polymerizing at least one 1-olefin with a catalyst system consisting essentially of a mixture of (1) a support which is a finely divided insoluble inorganic support material such as silica, alumina, zirconia or thoria or mixtures thereof containing titanium, zirconium or nickel prepared by fluidizing the finely divided support in the form of a bed with a substantially dry gas while adding to the bed at an elevated temperature, while fluidizing, a compound of the class consisting of titanium or zirconium or nickel esters, or halides or mixtures thereof which were further calcined at a higher temperature and (2) an organotin chromate containing the group essentially of the formula ##EQU1## and (3) cocatalytic amounts of an alkyl aluminum compound of the formula R.sub.a AlX.sub.