Clean, efficient metal electrolysis via som anodes

Abstract

In some aspects, the invention relates to apparatuses for recovering a metal comprising providing a sealed container for holding a molten electrolyte, the container having an interior surface; a liner disposed along at least a portion of the interior container surface; a cathode disposed to be in electrical contact with the molten electrolyte when the molten electrolyte is disposed in the container; a solid oxygen ion-conducting membrane disposed to be in ion-conducting contact with the electrolyte when the molten electrolyte is disposed in the container; an anode in contact with the solid oxygen ion-conducting membrane, the solid oxygen ion-conducting membrane electrically separating the anode from the molten electrolyte; and a power source for generating an electric potential between the anode and the cathode.

1 .- 17 . (canceled) 
     
     
         18 . A method for recovering a metal, comprising:
 (a) providing a sealed container for holding a molten electrolyte, the container having an interior surface;   (b) providing a liner disposed along at least a portion of the interior container surface;   (c) providing a cathode disposed to be in electrical contact with the molten electrolyte when the molten electrolyte is disposed in the container;   (d) providing a solid oxygen ion-conducting membrane disposed to be in ion-conducting contact with the electrolyte when the molten electrolyte is disposed in the container;   (e) providing an anode in contact with the solid oxygen ion-conducting membrane, the solid oxygen ion-conducting membrane electrically separating the anode from the molten electrolyte;   (f) dissolving at least a portion of an oxide of the metal into the electrolyte;   (g) establishing a non-oxidizing environment within the container; and   (h) generating an electric potential between the anode and the cathode, whereby the oxide of the metal is reduced to form metal.   
     
     
         19 . The method of  claim 18 , wherein the container comprises steel. 
     
     
         20 . The method of  claim 18 , wherein the container is electrically isolated from the cathode. 
     
     
         21 . The method of  claim 18 , wherein the interior surface includes a floor and the floor comprises carbon. 
     
     
         22 . The method of  claim 21 , wherein the liner extends from the floor upward along the interior surface of the container. 
     
     
         23 . The method of  claim 22 , wherein, during generation of the electric potential, the metal is recovered from metal oxide dissolved in the molten electrolyte and the metal collects on the floor of the container and wherein the liner extends to a level that prevents contact between the metal being recovered and the interior surface of the container. 
     
     
         24 . The method of  claim 18 , wherein the liner comprises carbon, boron nitride, titanium diboride, SiC, Si 3 N 4 , fused alumina or zirconia. 
     
     
         25 . The method of  claim 18 , wherein, during generation of the electric potential, the metal is recovered from a metal oxide dissolved in the molten electrolyte and the metal collects on a top surface of the molten electrolyte when the electrolyte is disposed in the container and wherein the liner extends from a first level below the metal-molten electrolyte interface to a second level above the metal-molten electrolyte interface, and the liner prevents contact between the metal-molten electrolyte interface and the interior surface of the container. 
     
     
         26 . The method of  claim 25 , wherein a side wall of the container and the liner define a passage between the interior of the container and a well external to the container. 
     
     
         27 . The method of  claim 26 , further comprising providing a partition disposed inside the container, the partition extending from a third level below the metal-molten electrolyte interface to a fourth level above the top surface of the metal, the third level being above a bottom surface of the container, and the partition preventing recovered metal from collecting on top of a portion of the molten electrolyte. 
     
     
         28 . The method of  claim 18 , further comprising providing a sheath disposed around at least a portion of the solid oxygen ion-conducting membrane, the sheath extending from a third level below the metal-molten electrolyte interface to a fourth level above the top surface of the metal, and the sheath preventing contact between the metal being recovered and the solid oxygen ion-conducting membrane. 
     
     
         29 . The method of  claim 28 , wherein the sheath comprises boron nitride, Si 3 N 4 , fused alumina or zirconia. 
     
     
         30 . The method of  claim 28 , the solid oxygen ion-conducting membrane and sheath defining an annular space between the membrane and sheath, the method further comprising providing a gas inlet in communication with the annular space. 
     
     
         31 . The method of  claim 18 , wherein the container is not electrically isolated from the cathode. 
     
     
         32 . The method of  claim 31 , wherein the interior surface includes a floor and the floor comprises carbon. 
     
     
         33 . The method of  claim 33   claim 32 , wherein the liner extends from the floor upward along the interior surface of the container to a level that prevents contact between molten electrolyte and the interior surface of the container. 
     
     
         34 . The method of claim  311   claim 33 , wherein the liner comprises boron nitride, Si 3 N 4 , fused alumina or zirconia. 
     
     
         35 . The method of  claim 18 , wherein the metal oxide is fed directly into the molten electrolyte. 
     
     
         36 . The method of  claim 18 , wherein the metal comprises aluminum, magnesium, lithium, beryllium, silicon, sodium, potassium or calcium. 
     
     
         37 . The method of  claim 36 , wherein the metal comprises aluminum, lithium, beryllium, silicon, sodium, or potassium. 
     
     
         38 . The method of  claim 37 , wherein the metal comprises aluminum.