Abstract: An improved supported chromium oxide catalyst, a process for preparing the catalyst and a process for polymerizing olefin monomers utilizing the catalyst are provided. In accordance with the preparation process, chromium oxide and a support containing one or more of silica, titania, thoria, alumina, zirconia or aluminophosphates are combined, impregnated with a metal salt and activated. The metal salt is selected from the group consisting of alkali metal salts, alkaline earth metal salts and mixtures thereof.

Abstract: An improved supported chromium oxide catalyst, a process for preparing the catalyst and a process for polymerizing olefin monomers utilizing the catalyst are provided. In accordance with the preparation process, chromium oxide and a support containing one or more of silica, titania, thoria, alumina, zirconia or aluminophosphates are combined, impregnated with a metal salt and activated. The metal salt is selected from the group consisting of alkali metal salts, alkaline earth metal salts and mixtures thereof.

Abstract: Sodium-free olefin polymerization catalysts having high polymerization activities and methods of preparing such catalysts are provided. A hydrolyzable silicate ester and a hydrolyzable acid-generating chromium compound are combined with water and an organic solvent whereby a hydrolysis reaction solution is formed comprising silica and chromium. Sufficient acid-neutralizing gelling agent is added to the solution to form a gelled silica-chromium catalyst and the catalyst is aged to stabilize its structure. Water and solvent are removed from the catalyst and the catalyst is activated.

Abstract: A silica hydrogel is contacted with a hydroxy-containing organic compound which is not completely miscible with water but which is sufficiently miscible with water so as to remove water, and thereafter the organic compound is removed by heating in an inert atmosphere prior to activation by heating in air. The heating in the inert atmosphere allows utilizing preferred organic compounds such as C.sub.5 and C.sub.6 alcohols which are desirable from a commercial standpoint because of the easy separation for recycle. In a preferred embodiment, the hydrogel is aged at a pH of 7 to 9 by means of either adding a base or by utilizing a chromium component containing bound nitrogen.

Abstract: A silica hydrogel containing chromium is aged under conditions such that at least a portion of the aging is carried out at a pH within the range of 7 to 9. The resulting hydrogel is converted to a xerogel by treating with a volatile organic liquid. The desired pH can be obtained either by adding a basic material such as ammonia to the hydrogel prior to or during the aging process or by using a chromium component which inherently gives a higher pH and/or resists the natural tendency for the pH to decrease during aging. An example of such a chromium compound is chloropentammine chromium(III) chloride. The resulting catalyst on activation is particularly suitable for olefin polymerization under conditions where higher melt flow polymer is desired.

Abstract: A silica hydrogel containing chromium is aged under conditions such that at least a portion of the aging is carried out at a pH within the range of 7 to 9. The resulting hydrogel is converted to a xerogel by treating with a volatile organic liquid. The desired pH can be obtained either by adding a basic material such as ammonia to the hydrogel prior to or during the aging process or by using a chromium component which inherently gives a higher pH and/or resists the natural tendency for the pH to decrease during aging. An example of such a chromium compound is chloropentammine chromium(III)chloride.

Abstract: A silica hydrogel is contacted with a hydroxy-containing organic compound which is not completely miscible with water but which is sufficiently miscible with water so as to remove water, and thereafter the organic compound is removed by heating in an inert atmosphere prior to activation by heating in air. The heating in the inert atmosphere allows utilizing preferred organic compounds such as C.sub.5 and C.sub.6 alcohols which are desirable from a commercial standpoint because of the easy separation for recycle. In a preferred embodiment, the hydrogel is aged at a pH of 7 to 9 by means of either adding a base or by utilizing a chromium component containing bound nitrogen.

Abstract: A method of producing silica compositions from hydrogels in which the hydrogel is washed in a first water-soluble organic liquid to remove a principal portion of the water. The washed composition is then washed in at least one second water-soluble organic liquid and the second organic liquid is removed from the composition by venting the second organic liquid from the composition at a temperature above the critical temperature of the second organic liquid to produce a silica composition.

Abstract: A method is provided for treating a hydrogel with a saturated, aliphatic alcohol selected from the group consisting of 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 2,2-dimethyl-1-propanol and 1-hexanol to remove water thereby producing a dried product that retains a porous structure and is particularly suitable upon impregnation with a polymerization catalyst for use in promoting the production of ethylene polymers of melt index in excess of about 6.6.

Abstract: A multiple zone apparatus for treating particulate solids and a method for treating particulate solids in seriatim multiple zones are provided. Particulate solids treatment such as the activation of chromium-silica olefin polymerization catalyst is carried out continuously by employing multiple fluidized beds with overflow of solids from one bed to the next lower bed. Each bed has its own source of heat and fluidizing gas to permit step-wise treatment of the particulate solids as particles pass through the system. Temperatures in each zone can be regulated for treatment of the solids in a predetermined manner. In a preferred embodiment each bed is transversely divided with a partition containing a hole sized for forwarding flow from the solids inlet side of the bed to the outlet side without backflow.

Abstract: A method is provided for treating a hydrogel with a saturated, aliphatic alcohol selected from the group consisting of 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 2,2-dimethyl-1-propanol and 1-hexanol to remove water thereby producing a dried product that retains a porous structure and is particularly suitable upon impregnation with a polymerization catalyst for use in promoting the production of ethylene polymers of melt index in excess of about 6.6.

Abstract: Olefin polymerization process employing a catalyst formed of a silica produced using lithium silicate. Ethylene polymers of higher melt index are produced than when sodium silicate is employed.

Abstract: A particulate catalyst support containing titanium is heated to activation temperature and thereafter impregnated with a .pi. bonded organochromium compound. Thereafter the chromium-containing catalyst is reactivated, at least a portion of the reactivation occurring in the presence of oxygen. Such catalysts are particularly suitable for the production of high melt index polymer from at least one mono-1-olefin containing 2 to 8 carbon atoms per molecule.

Abstract: A method for preparing silica-containing olefin polymerization catalysts, and the process performable therewith, the preparation involving adding an alkali metal silicate to an acid under defined conditions of addition to produce a hydrogel, recovering the gel in the substantially dry condition by employment of an oxygenated organic compound and impregnating the gel with a chromium compound.

Abstract: Olefin polymers are made using a chromium oxide catalyst on a support formed by adding an acidic material to a silicate solution containing titanium. This catalyst is capable of producing a polymer of an olefin having a high melt index and is of particular utility in the production of such polymer in a particle-form process.

Abstract: Large pore silica gel is produced by reacting an alkyoxy or aryloxy silane with an alkali metal hydroxide and then contacting the reaction product with a mineral acid to form a hydrogel from which a xerogel can be produced.

Abstract: Olefin polymers are made using a supported chromium oxide catalyst which is treated with a mixture of an organoboron compound and a hydrocarbyl aluminum hydrocarbyl oxide. This catalyst is capable of producing high shear response polymer and is of particular utility in the production of such polymer in a particle-form process.