Patents by Inventor Jochen Ullmann

Jochen Ullmann 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).

  • Process for leaching of precious metals
    Patent number: 5336474
    Abstract: A process is disclosed for the leaching of gold and silver from ores and ore concentrates through intimate contact of the ore or ore concentrate with an aqueous leach solution containing cyanide. The leach solution has a pH of 8 to 13. The leaching process takes place in the presence of an oxygen-releasing peroxo compound. The separation of the formed cyano complexes of gold and silver takes place in a known manner. During leaching, at least one peroxoborate compound is present, in an effective quantity, as the peroxo compound. The peroxoborate is preferably a sodium or calcium peroxoborate. Compared to previously known leaching techniques in the presence of hydrogen peroxide or calcium peroxide, the leaching process according to the present invention provides a higher and/or faster precious metal yield and/or minimizes the consumption of cyanide and/or oxidizing agent.
    Type: Grant
    Filed: October 6, 1992
    Date of Patent: August 9, 1994
    Assignee: Degussa Aktiengesellschaft
    Inventors: Manfred Diehl, Karl-Heinz Koenig, Eckhart Krone, Juergen Loroesch, Norbert Steiner, Jochen Ullmann, Annette Ziegler