Patents by Inventor Charles Semler

Charles Semler 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).

  • Acid resistant cement composition
    Patent number: 5989330
    Abstract: A cement composition for use in acidic environments containing an acid resistant particulate aggregate of fused mullite aggregate or other aggregate material, with quartz, and microsilica in combination with a colloidal silica sol binder and being substantially free of Na compounds and K compounds which react in the presence of sulfuric acid to form alkali sulfates in service, thus reducing the durability or the service life.
    Type: Grant
    Filed: December 12, 1997
    Date of Patent: November 23, 1999
    Assignee: Barrick Gold Corporation
    Inventors: Charles Semler, Thomas Hawisher, Herman Pieterse, Richard Williams