Vereinigte Aluminium-werke Aktiengesellschaft

Leuna-werke Ag

Hubertus Schmidt

Roland Thome

Arno Tissler

Klaus K Unger

Gunter Winkhaus

Reinhard Feige

Dieter Prescher

Rudiger Lange

Ulrich Bollmann

Albrecht Husmann

Seigfried Engels

The invention relates to a partially crystalline, transitional aluminum oxide containing 4-fold and 5-fold coordinated aluminum oxide in a ratio of at least 1:2. The invention also relates to a method of making this composition. The composition is particularly useful as starting material for manufacturing highly reactive molded articles. Accordingly, the invention also relates to this manufacturing process.

Partially crystalline, transitional aluminum oxides, methods for their

Synthetic crystalline aluminosilicate is prepared by an inorganic process from a reaction mixture, which contains, in an aqueous alkaline medium SiO.sub.2 and Al.sub.2 O.sub.3 or their hydrated derivatives or alkali silicates and aluminates, mineralizers and optionally seeding crystals, the reaction mixture containing: SiO.sub.2 /Al.sub.2 O.sub.3 in molar ratio of 15-40, OH.sup.- /SiO.sub.2 in molar ratio 0.1-0.2, and H.sub.2 O/SiO.sub.2 in molar ratio 20-60. The aluminosilicate produced by the process has a chemical composition expressed in molar ratios as: 0-3 M.sub.2 O:Al.sub.2 O.sub.3 :15-40 SiO.sub.2 :0-40 H.sub.2 O, where M represents an alkali cation. The aluminosilicate is useful in the preparation of catalysts and adsorbents.

Synthetic, crystalline aluminosilicate, method for its preparation as

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.

Method for modifying a zeolite

A process is disclosed for producing aluminum hydroxide in the form of gibbsite in particular shapes, suitable for use as a filler, flame retardant and/or fibrous reinforcement. The process includes the steps of crystallizing gibbsite from a Bayer process sodium aluminate liquor, in the presence of an additive comprising either a hydroxycarboxilic acid for producing needle shaped, rod-like hydrargillite or in the presence of a polyalcohol, fatty acid or lithium compound for producing platy or tabular gibbsite.

Method for the production of fillers and flame retardants based on

The present invention relates to a method of preparing crystalline, zeolitic aluminosilicates with SiO.sub.2 /Al.sub.2 O.sub.3 ratios of 20 or more. The method provides a rapid, two-stage crystallization process which avoids the formation of secondary crystalline phases. The first stage is conducted at a temperature between 240.degree. C. and 325.degree. C. for between about 1 and 20 minutes. The second stage is conducted at a temperature between about 120.degree. C. and 225.degree. C. for about 1 to 100 hours.

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Eitorf, Germany

Hubertus Schmidt