Patents by Inventor Frank B. Eisenhardt

Frank B. Eisenhardt 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).

  • Phosphate ore flotation
    Patent number: 4059509
    Abstract: The washing step that usually follows the deoiling of phosphate rougher concentrate is eliminated by adding lime to said rougher concentrate following the deoiling.
    Type: Grant
    Filed: January 9, 1976
    Date of Patent: November 22, 1977
    Assignee: Mobil Oil Corporation
    Inventors: Frank B. Eisenhardt, Stanislaus F. Muehlberger