Patent ID: 6719890
Filing Date: 2004-04-13
Classification: C25C

Abstract:
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.