Procedures and apparatus for electrolytic production of metals

Procedure for electrolysis of magnesium chloride to produce free magnesium metal, including the step of

• a. maintaining, in an enclosed cell chamber, a molten electrolytic bath containing magnesium chloride for electrolysis, free magnesium metal being lighter than said bath;
• and
• b. passing direct electric current through the bath between at least one anode and at least one cathode in contact with the bath for depositing free magnesium metal at said one cathode for upward flow along said cathode and evolving chlorine gas at said one anode for upward travel through said bath within an envelope diverging upwardly at a substantially constant slope;
• wherein the improvement comprises:
• c. said current-passing step comprising passing current through said bath between a major surface of said one anode that slants upwardly toward said one cathode throughout the active vertical extent of said one anode major surface with a slope greater than the slope of said envelope, and a major surface of said one cathode that faces and slants upwardly away from said one anode major surface throughout the active vertical extent of said one cathode major surface with a slope not more than about equal to the slope of said envelope, the lower extremity of the active vertical extent of said one cathode major surface being spaced from said one anode major surface by a distance sufficient to prevent contact and recombination of magnesium metal and chlorine gas respectively released at said last-mentioned cathode and anode surfaces, while maintaining a circulating flow of the bath directed entirely upwardly throughout a space defined between said last-mentioned cathode and anode surfaces and downwardly along a return flow path external to said space.