Patents Assigned to Northwest Aluminum Technology
  • Patent number: 7077945
    Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature of less than 900° C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom. A plurality of non-consumable Cu—Ni—Fe anodes and cathodes are disposed in a vertical direction in the electrolyte, the cathodes having a plate configuration and the anodes having a flat configuration to compliment the cathodes. The anodes contain apertures therethrough to permit flow of electrolyte through the apertures to provide alumina-enriched electrolyte between the anodes and the cathodes. Electrical current is passed through the anodes and through the electrolyte to the cathodes, depositing aluminum at the cathodes and producing gas at the anodes.
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: July 18, 2006
    Assignee: Northwest Aluminum Technologies
    Inventors: S. Craig Bergsma, Craig W. Brown, Donald R Bradford, Robert J. Barnett, Michael B. Mezner
  • Patent number: 6837982
    Abstract: A method of maintaining molten salt concentration in a low temperature electrolytic cell used for production of aluminum from alumina dissolved in a molten salt electrolyte contained in a cell free of frozen crust wherein volatile material is vented from the cell and contacted and captured on alumina being added to the cell. The captured volatile material is returned with alumina to cell to maintain the concentration of the molten salt.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: January 4, 2005
    Assignee: Northwest Aluminum Technologies
    Inventors: Robert J. Barnett, Michael B. Mezner, Donald R Bradford
  • Patent number: 6811676
    Abstract: An electrolytic cell for producing aluminum from alumina having a reservoir for collecting molten aluminum remote from the electrolysis.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: November 2, 2004
    Assignee: Northwest Aluminum Technologies
    Inventors: Donald R Bradford, Robert J. Barnett, Michael B. Mezner
  • Patent number: 6800191
    Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising providing a molten salt electrolyte having alumina dissolved therein in an electrolytic cell. A plurality of anodes and cathodes having planar surfaces are disposed in a generally vertical orientation in the electrolyte, the anodes and cathodes arranged in alternating or interleaving relationship to provide anode planar surfaces disposed opposite cathode planar surfaces, the anode comprised of carbon. Electric current is passed through anodes and through the electrolyte to the cathodes depositing aluminum at the cathodes and forming carbon containing gas at the anodes.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: October 5, 2004
    Assignee: Northwest Aluminum Technologies
    Inventors: Robert J. Barnett, Michael B. Mezner, Donald R Bradford
  • Patent number: 6719889
    Abstract: A method of producing aluminum in an electrolytic cell comprising the steps of providing an anode in a cell, preferably a non-reactive anode, and also providing a cathode in the cell, the cathode comprised of a base material having low electrical conductivity reactive with molten aluminum to provide a highly electrically conductive layer on the base material. Electric current is passed from the anode to the cathode and alumina is reduced and aluminum is deposited at the cathode. The cathode base material is selected from boron carbide, and zirconium oxide.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: April 13, 2004
    Assignee: Northwest Aluminum Technologies
    Inventor: Craig W. Brown
  • Patent number: 6719890
    Abstract: A method of producing aluminum from alumina in an electrolytic cell including using a cathode comprised of a base material having low electrical conductivity and wettable with molten aluminum to form a reaction layer having a high electrical conductivity on said base layer and a cathode bar extending from said reaction layer through said base material to conduct electrical current from said reaction layer.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: April 13, 2004
    Assignee: Northwest Aluminum Technologies
    Inventor: Craig W. Brown
  • Patent number: 6558525
    Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature of less than 900° C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom. A plurality of non-consumable anodes and cathodes are disposed in a vertical direction in the electrolyte, the cathodes having a plate configuration and the anodes having a flat configuration to compliment the cathodes. The anodes contain apertures therethrough to permit flow of electrolyte through the apertures to provide alumina-enriched electrolyte between the anodes and the cathodes. Electrical current is passed through the anodes and through the electrolyte to the cathodes, depositing aluminum at the cathodes and producing gas at the anodes.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: May 6, 2003
    Assignee: Northwest Aluminum Technologies
    Inventors: Donald R. Bradford, Robert J. Barnett, Michael B. Mezner
  • Patent number: 6497807
    Abstract: A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.
    Type: Grant
    Filed: November 25, 2000
    Date of Patent: December 24, 2002
    Assignee: Northwest Aluminum Technologies
    Inventors: Craig W. Brown, Richard J. Brooks, Patrick B. Frizzle, Drago D. Juric
  • Patent number: 6485628
    Abstract: An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises a molten electrolyte having the following ingredients: (a) AlF3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and (b) about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound may be, for example, a fluoride, oxide, or carbonate. The metal can be nickel, iron, copper, cobalt, or molybdenum. The bath can be employed in a combination that includes a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the bath of the present invention during electrolytic reduction of alumina to aluminum can improve the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode.
    Type: Grant
    Filed: November 25, 2000
    Date of Patent: November 26, 2002
    Assignee: Northwest Aluminum Technology
    Inventors: Craig W. Brown, Richard J. Brooks, Patrick B. Frizzle, Drago D. Juric
  • Patent number: 6436272
    Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. A plurality of non-consumable anodes are disposed substantially vertically in the electrolyte along with a plurality of monolithic hollow cathodes. Each cathode has a top and bottom and the cathodes are disposed vertically in the electrolyte and the anodes and the cathodes are arranged in alternating relationship. Each of the cathodes is comprised of a first side facing a first opposing anode and a second side facing a second opposing anode. The first and second sides are joined by ends to form a reservoir in the hollow cathode for collecting aluminum therein deposited at the cathode.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: August 20, 2002
    Assignee: Northwest Aluminum Technologies
    Inventors: Craig W. Brown, Patrick B. Frizzle
  • Patent number: 6419813
    Abstract: Cathode connector means for low temperature aluminum smelting cell for connecting titanium diboride cathode or the like to bus bars.
    Type: Grant
    Filed: November 25, 2000
    Date of Patent: July 16, 2002
    Assignee: Northwest Aluminum Technologies
    Inventors: Craig W. Brown, Theodore R. Beck, Patrick B. Frizzle
  • Patent number: 6419812
    Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: July 16, 2002
    Assignee: Northwest Aluminum Technologies
    Inventors: Theodore R. Beck, Craig W. Brown
  • Patent number: 6379512
    Abstract: An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises molten electrolyte having the following ingredients: AlF3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound is, a fluoride; oxide, or carbonate. The metal is nickel, iron, copper, cobalt, or molybdenum. The bath is employed in a combination including a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the instant bath during electrolytic reduction of alumina to aluminum improves the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode.
    Type: Grant
    Filed: November 25, 2000
    Date of Patent: April 30, 2002
    Assignee: Northwest Aluminum Technology
    Inventors: Craig W. Brown, Richard J. Brooks, Patrick B. Frizzle, Drago D. Juric
  • Patent number: 6258247
    Abstract: An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises a molten electrolyte having the following ingredients: (a) AlF3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and (b) about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound may be, for example, a fluoride, oxide, or carbonate. The metal can be nickel, iron, copper, cobalt, or molybdenum. The bath can be employed in a combination that includes a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the bath of the present invention during electrolytic reduction of alumina to aluminum can improve the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: July 10, 2001
    Assignee: Northwest Aluminum Technology
    Inventors: Craig W. Brown, Richard J. Brooks, Patrick B. Frizzle, Drago D. Juric