Electrolytic extraction of magnesium from a magnesium-containing aluminum alloy

A method for producing magnesium metal from a magnesium-containing aluminum alloy, the method comprising the steps of:

• forming a molten salt electrolyte in which a rare earth chloride and magnesium chloride have been included, such that rare earth metal cations, magnesium cations, and chloride anions are present within the molten salt electrolyte;
• electrolytically demagging the magnesium-containing aluminum alloy by imposing a potential between a cathode and the aluminum-magnesium alloy while both are immersed in the molten salt electrolyte, such that magnesium within the magnesium-containing aluminum alloy is oxidized so as to form magnesium cations which are reduced at the cathode to produce molten magnesium metal;
• and
• electrolytically regenerating the molten salt electrolyte by imposing a potential between the cathode and an anode so as to produce magnesium cations which are electrolytically reduced at the cathode to produce molten magnesium metal;
• wherein magnesium oxide which forms in the molten salt electrolyte is reacted with the rare earth metal cations and the chloride anions to form magnesium chloride and rare earth oxychloride.

A method for producing magnesium metal from a magnesium-containing aluminum alloy, the method comprising the steps of:

• forming a molten salt electrolyte for the selective electrolytic oxidation of said magnesium in said alloy, said electrolyte comprising rare earth metal cations, magnesium cations, anti chloride anions;
• electrolytically demagging the magnesium-containing aluminum alloy by imposing a potential between an iron-based cathode and the aluminum-magnesium alloy while both are immersed in the molten salt electrolyte, such that the magnesium is oxidized so as to form magnesium cations which are reduced at the cathode to produce molten magnesium metal, solid magnesium oxide forming in said electrolyte during said electrolysis and concomitantly reacting with rare earth metal cations and chloride anions to form rare earth oxychloride and magnesium anions;
• discontinuing said demagging step;
• and
• electrolytically regenerating the molten salt electrolyte by imposing a potential between the iron-based cathode and a carbon-based anode so as to electrolytically reduce said rare earth oxychloride and said magnesium anions at the iron-based cathode to produce molten magnesium metal, and so as to produce carbon monoxide gas at the carbon-based anode;
• and
• wherein said rare earth chloride is regenerated from the rare earth oxychloride during the electrolytic regenerating step.