Patents by Inventor Robert W. Au

Robert W. Au 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: 4346062
    Abstract: A process is disclosed for recovering zinc from a material containing zinc sulfide. The zinc sulfide-containing material is chlorinated in an aqueous medium to form zinc chloride and elemental sulfur. A water-immiscible solvent (preferably inert) for the sulfur is added to the aqueous chlorinating solution during the chlorination process. The aqueous solution which contains zinc values is separated from the water-immiscible solvent containing sulfur. The zinc values can be recovered from the aqueous layer.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: August 24, 1982
    Assignee: Occidental Research Corporation
    Inventor: Robert W. Au
  • Patent number: 4206023
    Abstract: A process is disclosed for the separation and recovery of zinc from material in which it is contained as a sulfide. Zinc sulfide containing material is chlorinated in an aqueous medium in the presence of elemental chlorine and ferric/ferrous ions to form a solution containing zinc chloride, iron chloride and elemental sulfur. The solution is treated with elemental chlorine and alkali to precipitate the iron (e.g. at about pH 3 to 4). Zinc chloride is recovered from the solution by means known to those skilled in the art such as by electrolysis. The precipitated iron is recycled for use as a secondary chlorinating solution to treat the solid residue of the initial chlorination leaching step.
    Type: Grant
    Filed: May 12, 1978
    Date of Patent: June 3, 1980
    Assignee: Occidental Research Corporation
    Inventor: Robert W. Au