Patents by Inventor Gunnar Hannestad

Gunnar Hannestad 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).

  • Method of precipitation of pure aluminiumchloride from solutions which contain ions of aluminium and magnesium
    Patent number: 4297327
    Abstract: Method of producing aluminiumchloride with a low content of magnesium from hydrochloric acid solutions which contain ions of aluminium and magnesium and from which the aluminiumchloride is precipitated by hydrochloric gas and where the precipitation is carried out continuously in cascade so that the major part of the aluminium will be precipitated from solutions in which the ratio between aluminium and magnesium calculated as g Al.sup.+3 /g Mg.sup.+2 is above 0,5. Produced aluminiumchloride may be transformed to aluminiumoxide by calcination.
    Type: Grant
    Filed: February 4, 1980
    Date of Patent: October 27, 1981
    Assignee: Elkem-Spigerverket A/S
    Inventors: Norvald Gjelsvik, Gunnar Hannestad, Ingleif Hundere, Jan H. Torgersen
  • Apparatus for liquid-liquid countercurrent extraction
    Patent number: 3997445
    Abstract: An apparatus for countercurrent extraction of a dissolved material from a first liquid phase to a second liquid phase is disclosed. The apparatus comprises overflow provision for each of the liquid phases with preferably adjustable overflow for the lower liquid phase whereby desired control of interface level can be obtained.
    Type: Grant
    Filed: July 3, 1975
    Date of Patent: December 14, 1976
    Assignee: Forskningsgruppe For Sjeldne, Jordarter
    Inventor: Gunnar Hannestad