Patents by Inventor Pak Kuen Louie

Pak Kuen Louie 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: 5759512
    Abstract: The invention provides a method of regenerating dithiophosphorus extractants such as dithiophosphoric acids, dithiophosphonic acids and dithiophosphinic acids from their sulfur-sulfur bonded oxidation products contained in an organic solution. The process generates active hydrogen for regenerating the spent dithiophosphorus extractants. Advantageously, this active hydrogen originates either from introducing a reactive metal into a liquid mixture containing the organic solution and an acidic aqueous solution to form nascent hydrogen or from using hydrogen gas in the presence of a catalyst in the organic solution. The active hydrogen generated in the process breaks the sulfur-sulfur bonds of the dithiophosphorus molecules to form the corresponding dithiophosphorus acids.
    Type: Grant
    Filed: June 4, 1996
    Date of Patent: June 2, 1998
    Assignees: Cytec Technology Corp., Inco Limited
    Inventors: William Andrew Rickelton, Indje Ognianov Mihaylov, Bruce John Love, Pak Kuen Louie, Eberhard Krause