Patents by Inventor Raija-Leena Gisler

Raija-Leena Gisler 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: 4383979
    Abstract: Zinc, copper and cadmium are recovered from their ferrites by subjecting the ferrites to a sulfuric acid bearing solution in the presence of potassium, sodium or ammonium ions under atmospheric conditions at C. to precipitate the iron present in the ferrites as jarosite, separating at least a portion of the jarosite-bearing solid material from the solution before recycling the solution to a neutral leach, from which a copper and cadmium bearing solution is recovered and to which acid and calcine are also fed, feeding the solid obtained from the neutral leach to the said ferrite treatment stage classifying the solid obtained from the neutral leach into a finer and coarser fraction, feeding the finer fraction to the ferrite treatment stage, comminuting the coarser fraction by grinding, leaching or milling and recycling the comminuted fraction to the process.
    Type: Grant
    Filed: August 26, 1980
    Date of Patent: May 17, 1983
    Assignee: Outokumpu Oy
    Inventors: Jussi K. Rastas, Lars-Goran Bjorkqvist, Raija-Leena Gisler, Simo S. Liukkonen