Abstract: A process for the production of zeolites with a high Si/Al atomic ratio formed by the conversion of amorphous polysilicas (polysilacic acid) with a source of aluminum ions and optionally a template wherein the conversion occurs at a temperature of less than about 100° C., wherein ammonium hydroxide and/or an alkali metal silicate is added to the conversion solution.

Abstract: A column for capillary chromatographic separations, for example high performance liquid chromatography, capillary electrochromatography, or supercritical chromatography, comprises a column bed of packing material arranged in the inner bore of a capillary, wherein said bed of packing material is completely immobilized by a thermal treatment. The thermal treatment preferably comprises moving a heating wire along the column while applying pressure to the column using a high pressure pump.

Abstract: The invention relates to a crystalline zeolite-like gallosilicate having an atomic ratio of Si/Ga in the outer crystalline surface that is not larger than the average Si/Ga ratio for the whole of the crystal. The invention also relates to a method of making such a gallosilicate comprising the hydrothermal crystallization of a strictly inorganic reaction mixture having the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05-1.0; and H.sub.2 O/SiO.sub.2 =10-1,000. The invention further relates to the above-described method wherein said reaction mixture is prepared by adding an aged gel to a first mixture, the first mixture preferably having a composition with the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05 to 1.0; and H.sub.2 O/SiO.sub.2 =20 to 100.

Abstract: Gallosilicates can be formed in the absence of structure-guiding organic hydrocarbons or amines by(a) combining water, a base, a gallium material selected from the group consisting of alkali metal gallates, Ga.sub.2 O.sub.3 and hydrated derivatives of Ga.sub.2 O.sub.3, and gallium salts optionally in aqueous solution, with a powder consisting essentially of particles of silicon dioxide or a hydrated derivative thereof having a diameter of 0.1 to 5 microns and a specific surface area of 20-22 m.sup.2 /g in amounts such that the atomic ratio of silicon to gallium is at least 10 to form an alkaline aqueous reaction mixture; and(b) heating the reaction mixture to produce zeolite-like gallosilicates. These materials are advantageously recovered from the reaction mixture and subjected to ion exchange to replace any alkali metal or alkaline-earth metal ions present with protons.

Abstract: The invention relates to a crystalline zeolite-like gallosilicate having an atomic ratio of Si/Ga in the outer crystalline surface that is not larger than the average Si/Ga ratio for the whole of the crystal. The invention also relates to a method of making such a gallosilicate comprising the hydrothermal crystallization of a strictly inorganic reaction mixture having the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05-1.0; and H.sub.2 O/SiO.sub.2 =10-1,000. The invention further relates to the above-described method wherein said reaction mixture is prepared by adding an aged gel to a first mixture, the first mixture preferably having a composition with the following molar ratios: SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5; OH.sup.- /SiO.sub.2 =0.05 to 1.0; and H.sub.2 O/SiO.sub.2 =20 to 100.

Abstract: Disclosed is a method for preparing crystalline gallosilicates having a molar ratio of SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5 an having a more uniform particle size with enhanced catalytic activity. According to the method of the invention, crystalline gallosilicates are prepared by adding an aged, gallosilicate nuclei-forming gel having a molar ratio of SiO.sub.2 /Ga.sub.2 O.sub.3 .gtoreq.5 to an aqueous, alkaline solution containing reactive silicon and gallium compounds to form a mixture. The mixture is then subjected to hydrothermal crystallization conditions to form the crystalline gallosilicate. The gallosilicates prepared by the disclosed method is useful for the preparation of catalysts and adsorbents and in processes for converting low molecular weight hydrocarbons to higher aliphatics and aromatic compounds.

Abstract: Disclosed is a zeolite and a process for modifying a zeolite, which includes alkalizing the zeolite, and calcining the alkalized zeolite. The resultant modified zeolite has improved selectivity characteristics.