Patents by Inventor Leonard P. Stephenson

Leonard P. Stephenson 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).

  • Flotation of Cu and Pb sulfide concentrates containing carbonates
    Patent number: 4351668
    Abstract: A process for the beneficiation of lead or copper-lead sulphide ore or concentrate containing calcium and magnesium carbonates wherein the ore or concentrate is conditioned with a limited amount of sulphuric acid to form an acidic slurry and subjecting the acidic slurry to froth flotation whereby an upgraded concentrate and a tailing comprising calcium and magnesium sulphate are obtained.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: September 28, 1982
    Assignee: Cominco Ltd.
    Inventors: Leonard P. Stephenson, Arthur A. Schweizer