Patents by Inventor Robert M. Griffith

Robert M. Griffith 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).

  • Materials and processes for flotation of mineral substances
    Patent number: 4139455
    Abstract: This invention provides a method of concentrating a metaliferous ore containing also substantial quantities of pyrites and/or pyrrhotite and/or sphalerite and comprises subjecting an aqueous pulp of the ore to a froth flotation process in the presence of a depressant and in which (1) pyrites and/or pyrrhotite, and/or (2) sphalerite, is depressed by using as the depressant an amine in which at least 20% of the total number of amine groups are tertiary amine groups and in which the number of quaternary amine groups present is zero or is less than one-third the number of tertiary amine groups.
    Type: Grant
    Filed: November 4, 1975
    Date of Patent: February 13, 1979
    Assignee: Allied Colloids Limited
    Inventors: Robert M. Griffith, Christopher Parkinson, Ronald A. Palmer
  • Processes for flotation of mineral substances
    Patent number: 4078993
    Abstract: A method of concentrating a metalliferous ore containing also substantial quantities of pyrites and/or pyrrhotite and/or sphalerite and comprises subjecting an aqueous pulp of the ore to a froth flotation process in the presence of a depressant and in which (1) pyrites and/or pyrrhotite, and/or (2) sphalerite, is depressed by using as the depressant a condensation product of an aldehyde with a compound containing at least two amine or amide groups.
    Type: Grant
    Filed: February 20, 1976
    Date of Patent: March 14, 1978
    Assignee: Allied Colloids Limited
    Inventors: Robert M. Griffith, Christopher Parkinson, Ronald A. Palmer