Cathode for a hall-heroult type electrolytic cell for producing aluminum
AssigneeNorthwest Aluminum Technologies
InventorCraig W. Brown
Life of this patent
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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.
Claims16
A method of producing aluminum from alumina in an electrolytic cell comprising the steps of:
- (a) providing a molten salt electrolyte in an electrolytic cell having alumina dissolved in the molten electrolyte comprised of at least one or more alkali metal fluorides and at least one other metal fluoride, the molten electrolyte having a surface and having a frozen crust thereon, the cell having a bottom and sides extending upwardly from said bottom to contain said electrolyte;
- (b) providing an anode extending through said surface into said electrolyte;
- (c) providing a cathode on said bottom said cell, said cathode comprised of:
- (i) a base material having high electrical resistivity and reactive with molten aluminum to form a reaction layer on said base material wettable with molten aluminum to maintain a layer of molten aluminum on the reaction layer;
- and
- (ii) means for conducting electrical current from said molten aluminum layer;
- and
- (d) passing electric current from said anode through said electrolyte to said cathode thereby reducing said alumina in said electrolyte and depositing aluminum at said cathode.
A method of producing aluminum from alumina in an electrolytic cell comprising the steps of:
- (a) providing a molten salt electrolyte in an electrolytic cell having alumina dissolved in the molten electrolyte, the molten electrolyte having a surface, the cell having a bottom and sides extending upwardly from said bottom to contain said electrolyte;
- (b) providing an anode extending through said surface into said electrolyte;
- (c) providing a cathode on said bottom said cell, said cathode comprised of:
- (i) a base material comprised of boron carbide;
- (ii) a layer of aluminum carbide on said base material, said aluminum carbide wettable with molten aluminum;
- and
- (iii) a layer of molten aluminum on said aluminum carbide;
- (iv) a cathode bar in electrical communication with said layer of molten aluminum;
- (d) passing electric current from said anode through said electrolyte to said cathode;
- and
- (e) reducing said alumina and depositing aluminum at said cathode.
A method of producing aluminum in an electrolytic cell comprising the steps of:
- (a) providing molten salt electrolyte at a temperature greater than 900° C. in an electrolytic cell having alumina dissolved in said electrolyte;
- (b) providing an anode in said electrolyte;
- (c) passing electric current from an anode through said electrolyte to a cathode disposed on the bottom of said cell, said cathode comprised of:
- (i) a boron carbide base material wettable with molten aluminum forming a reaction layer on said base material wettable by a layer of molten aluminum;
- and
- (ii) a cathode bar in electrical communication with said layer of molten aluminum, and
- (d) reducing said alumina and depositing aluminum at said cathode.
Dependencies are inferred from the claim text.