Patents by Inventor Tuula Hämäläinen, legal representative

Tuula Hämäläinen, legal representative 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: 7785395
    Abstract: The invention relates to a method for recovering gold from a sulphidic concentrate, particularly one containing arsenopyrite and/or pyrite, hydro-metallurgically. The concentrate is first subjected to leaching with a concentrated solution of alkali chloride and copper (II) chloride, by means of which the copper minerals and some of the gold in the concentrate are made to dissolve. Elemental sulphur and precipitated iron and arsenic compounds are separated from the leaching residue using physical separation methods, whereby the first intermediate is obtained, which contains gold-bearing sulphide minerals and gangue minerals as well as the gold that remains undissolved. The free gold that remains undissolved is separated by means of gravity separation methods. After gravity separation, additional comminution is carried out, after which the sulphide minerals are decomposed and the gold-containing solution or residue is routed to the concentrate leaching circuit.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: August 31, 2010
    Assignee: OUTOTEC OYJ
    Inventors: Jaakko Leppinen, Olli Hyvärinen, Seppo Heimala, Veikko Palosaari, Matti Hämäläinen, Tuula Hämäläinen, legal representative