Patent ID: 6800191
Filing Date: 2004-10-05
Classification: C25C

Abstract:
A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of:(a) providing a molten salt electrolyte consisting essentially of fluoride salts at a temperature of less than 900Â° C. having alumina dissolved therein in an electrolytic cell, said electrolyte having a surface, said cell having a liner for containing said electrolyte, said liner having a bottom and walls extending upwardly from said bottom; (b) providing a plurality of anode plates and cathode plates having planar surfaces disposed in a vertical orientation in said electrolyte, said anode plates and cathode plates arranged in alternating relationship to provide anode planar surfaces disposed opposite cathode planar surfaces to define a region therebetween, the cathode plates comprised of material substantially inert to molten aluminum the anode plates comprised of carbon; and (c) passing electrical current through said anode plates and through said electrolyte to said cathode plates, depositing aluminum at said cathode plates and forming a carbon-containing gas at said anode plates, said cell having a decomposition voltage for alumina in the range of 1.63 to 1.73 volts.