Patents by Inventor Robert W. Leibfried

Robert W. Leibfried 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).

  • Regeneration of activated carbon
    Patent number: 4407725
    Abstract: Spent activated carbon previously used to remove humate-type organic impurities from an aqueous inorganic acid solution is regenerated by a specific chemical regeneration process. According to this process, the spent carbon is subjected to the following treatments: (1) a first water wash, (2) a caustic wash in which at least 1.5% free caustic is maintained, (3) a warm and preferably hot water wash, and (4) an optional periodic acid wash. The process is particularly applicable to regenerating activated carbon used to remove humates from wet process phosphoric acid.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: October 4, 1983
    Assignee: International Minerals & Chemical Corp.
    Inventors: Hanceford L. Allen, William W. Berry, Robert W. Leibfried