Patents by Inventor Knud C. B. Knudsen

Knud C. B. Knudsen 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).

  • Patent number: 4504458
    Abstract: Gypsum as a byproduct in the manufacture of phosphoric acid is converted into potassium sulphate or sodium sulphate by subjecting an aqueous slurry to anion exchange under acidic conditions. Adding solid potassium chloride to the obtained solution of potassium sulphate causes the latter to crystallize in pure state, the potassium chloride solution recovered after filtering off the crystallized potassium sulphate being used for the regeneration of the anion exchanger.
    Type: Grant
    Filed: September 1, 1983
    Date of Patent: March 12, 1985
    Assignee: Superfos A/S
    Inventor: Knud C. B. Knudsen