Patents by Inventor Leif R. Haugen

Leif R. Haugen 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: 3975189
    Abstract: A method for selectively recovering metals from generally sulphidic particulate materials containing metals selected from nickel, copper and precious metals in which the particulate material is preferentially leached in an agitated chloride solution containing cuprous ions by the action of chlorine. The redox potential of the solution increases upon feeding chlorine thereto and decreases upon feeding particulate material thereto, and the rate of feeding of chlorine is controlled relative to the rate of feeding of material to control the redox potential substantially at or below a selected potential at which the metal is leached preferentially with respect to other metals in the material. Nickel is leached preferentially with respect to copper and precious metals in a matte, for example, to produce a nickel-rich solution and to concentrate the precious metals in a nickel-depleted residue.
    Type: Grant
    Filed: June 24, 1974
    Date of Patent: August 17, 1976
    Assignee: Falconbridge Nickel Mines Limited
    Inventor: Leif R. Haugen