Aluminum low temperature smelting cell metal collection

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 in an electrolytic cell having alumina dissolved therein, the electrolyte maintained at a temperature of less than 900° C., the cell having an anodic liner for containing said electrolyte, said liner having an anodic bottom and walls including at least one end wall extending upwardly from said bottom, said anodic liner being substantially inert with respect to said molten electrolyte, the molten electrolyte containing 1 to 30 wt. % undissolved alumina;
• (b) providing a plurality of non-consumable anodes disposed substantially vertically in said electrolyte and a plurality of cathodes disposed vertically in said electrolyte, said anodes and said cathodes arranged in alternating relationship, said anodes electrically connected to said anodic liner, the liner and walls comprised of an Ni—Cu—Fe alloy;
• (c) passing an electric current at a current density in the range of 0.1 to 1.5 A/cm2through said anodic liner to said anodes, through said electrolyte to said cathodes, depositing aluminum on said cathodes, and generating oxygen bubbles at the anodes and said anodic liner, said bubbles stirring said electrolyte and maintaining said undissolved alumina in suspension;
• (d) collecting molten aluminum from said cathodes in a tubular member positioned underneath said cathodes, said tubular member in liquid communication with each cathode to collect said molten aluminum therefrom, said tubular member electrically insulated from said anodic bottom;
• and
• (e) delivering molten aluminum through said tubular member to a molten aluminum reservoir, said molten aluminum collected from said cathodes and delivered to said reservoir while avoiding contact of the molten aluminum with said anodic bottom.

A system for producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the system comprised of:

• (a) an electrolytic cell having an anodic liner for containing a molten salt electrolyte having alumina dissolved therein, said liner having an anodic bottom and walls including at least one end wall extending upwardly from said bottom, said anodic liner being substantially inert with respect to said molten electrolyte;
• (b) a plurality of non-consumable anodes disposed substantially vertically in said electrolyte in said cell and a plurality of cathodes disposed vertically in said electrolyte, said anodes and said cathodes arranged in alternating relationship, said anodes electrically connected to said anodic liner;
• (c) means for passing an electric current through said anodic liner to said anodes, through said electrolyte to said cathodes in response to passing electric current through said electrolyte, depositing aluminum on said cathodes, and generating oxygen bubbles at the anodes and said anodic liner, said bubbles stirring said electrolyte;
• (d) a tubular member positioned underneath said cathodes for collecting molten aluminum from said cathodes, said tubular member in liquid communication with each cathode to collect said molten aluminum therefrom while excluding electrolyte;
• and
• (e) a molten aluminum reservoir located substantially opposite said anodes and cathodes in fluid communication with said tubular member for receiving molten aluminum delivered from said tubular member, said tubular member adapted to collect said molten aluminum from said cathodes to deliver said molten aluminum to said reservoir while avoiding contact of the molten aluminum with said anodic bottom.