Patents by Inventor Manfred Kullack

Manfred Kullack has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for the production of coarse crystalline alumina
    Patent number: 4374119
    Abstract: The invention describes a process for the production of coarse crystalline alumina from aluminum hydroxide, which after preparation by known methods is advantageously useful for abrasives, lapping and polishing purposes or for refractory materials. The process is characterized by aluminum hydroxide, either directly or after previous partial dehydration in the range 200.degree.-550.degree. C., being added with a mineralizer of compound type x(BF.sub.4).sub.n, wherein x stands for NH.sub.4 and metallic elements and n is for the formal valence of x, and subsequently is subjected to an elevated temperature treatment between 750.degree. C. and a value higher than the phase change temperature to .alpha.-Al.sub.2 O.sub.3.
    Type: Grant
    Filed: September 16, 1981
    Date of Patent: February 15, 1983
    Assignee: Swiss Aluminium Ltd.
    Inventors: Bernhard Schepers, Volker Nobbe, Bernd Schroder, Werner Borer, Manfred Kullack