Patents by Inventor Werner Czysch

Werner Czysch 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).

  • Production of low-fluorine gypsum as a by-product in a phosphoric acid process
    Patent number: 4026990
    Abstract: A process for purifying waste gypsum from the wet phosphoric acid process to a maximum fluorine content of 0.25 % by weight based on the anhydride, which comprises adding active silicic acid in two portions during the course of the phosphoric acid process, wherein at least half the total amount of silicic acid added is added during the decomposition of the crude phosphate and the remainder is added after the end of the decomposition but before the waste gypsum is filtered off, and the waste gypsum, after it has been filtered, is made into a suspension with water, separated from the liquid phase and dried.
    Type: Grant
    Filed: December 11, 1975
    Date of Patent: May 31, 1977
    Assignee: Chemie Linz Aktiengesellschaft
    Inventors: Werner Czysch, Walter Muller, Heinz Goller