Patent ID: 6911134

Claim:
A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell in which each of the anode and cathode operate at their respective maximum reaction rates depending on cell operating conditions including applied voltage and cell materials and cell geometry, said method comprising providing a molten salt electrolyte having a cation selected from one or more of the alkali metals, the alkaline earth metals, the eutectics and mixtures thereof, providing an anode at which oxygen can be evolved, providing a cathode including a metal oxide to be reduced, providing a third electrode of an alkali metal or an alkaline earth metal or mixtures or alloys thereof, providing a power supply connecting the anode and the third electrode, and providing a power supply connecting the cathode and the third electrode, whereby establishing and independently controlling voltage potentials between the third electrode and each of the anode and the cathode permits reduction of the metal oxide to the metal without either the anode reaction rate or the cathode reaction rate being limited by the other, resulting in substantially complete reduction of the metal oxide.