Patents Assigned to North American Pallidium Ltd.
  • Metal leaching and recovery process
    Patent number: 5364444
    Abstract: A process for extracting metals from a flotation concentrate containing gold, platinum group minerals, copper, nickel and sulfur. The process involves roasting the concentrate in the presence of oxygen to reduce the sulfur content of the concentrate to approximately two percent; leaching the roasted concentrate with an acid solution containing hydrochloric and nitric acids to dissolve substantially all of the metals; and recovering the metals from the solution.
    Type: Grant
    Filed: July 8, 1993
    Date of Patent: November 15, 1994
    Assignee: North American Pallidium Ltd.
    Inventors: C. Dale McDoulett, Jr., George W. Reschke