Patents by Inventor Kenneth E. Hjelmstad

Kenneth E. Hjelmstad 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).

  • Method for particle stabilization by use of cationic polymers
    Patent number: 4925247
    Abstract: A method of increasing recovery of mineral and metals during in-situ chemical leaching of earth material by injection of a treating fluid which comprises cationic, organic polymers which are made up of long chain hydrocarbon molecules of very great molecular weight (in excess of 1000 and as great as 1,000,000). Maintaining clays in a flocculated state and preventing the formation of colloidal particles improves permeability during chemical leaching of clay bearing earth materials.
    Type: Grant
    Filed: December 27, 1988
    Date of Patent: May 15, 1990
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventor: Kenneth E. Hjelmstad