Methods and apparatuses for efficient metals production, separation, and recycling by salt- and argon-mediated distillation with oxide electrolysis, and sensor device related thereto

Abstract

In one aspect, the present invention is directed to methods and apparatuses for recovering target metals from scrap. In some embodiments, the methods comprise dissolving a portion of a mixed metal scrap into a molten salt to form a molten salt and metal mixture, the scrap including a target metal species and at least one contaminant metal species; bubbling a gas through the molten salt and metal mixture to form a gas and metal vapor mixture comprising target metal vapors; and condensing at least a portion of the target metal vapors. In some embodiments, the apparatuses comprise a housing; a divider at least partially disposed within the housing, the divider forming at least a first chamber, a second chamber, and a fluid conduit between the first and second chambers; a top wall cooperating with a lower housing wall and at least one of the plurality of side walls to enclose the second chamber; a plurality of gas inlets disposed in the second chamber; and a gas outlet in fluid communication with the second chamber.

What is claimed is: 
     
         1 . A method for recovering a target metal, comprising:
 (a) providing a molten salt;   (b) dissolving a portion of a mixed metal scrap into the molten salt to form a molten salt and metal mixture, the mixed metal scrap comprising a target metal species and at least one contaminant metal species;   (c) bubbling a gas through the molten salt and metal mixture to form a gas and metal vapor mixture, the gas and metal vapor mixture comprising target metal vapors; and   (d) condensing at least a portion of the target metal vapors.   
     
     
         2 . The method of  claim 1 , wherein the mixed metal scrap comprises an oxide of the target metal. 
     
     
         3 . The method of  claim 1 , wherein the gas is inert. 
     
     
         4 . The method of  claim 1 , wherein the gas is argon. 
     
     
         5 . The method of  claim 1 , wherein the dissolving step comprises melting the mixed metal scrap. 
     
     
         6 . The method of  claim 1 , wherein the target metal comprises magnesium, calcium or a lanthanide. 
     
     
         7 . The method of  claim 1 , wherein the target metal comprises magnesium, calcium, or samarium. 
     
     
         8 . The method of  claim 1 , wherein the target metal is calcium or magnesium. 
     
     
         9 . An apparatus for recovering a target metal, comprising:
 (a) a housing comprising a lower wall and a plurality of side walls;   (b) a divider at least partially disposed within the housing, the divider forming within the housing at least a first chamber, a second chamber, and a fluid conduit between the first and second chambers;   (c) a top wall cooperating with the lower wall and at least one of the plurality of side walls to enclose the second chamber;   (d) a plurality of gas inlets disposed in the second chamber; and   (e) a gas outlet in fluid communication with the second chamber.   
     
     
         10 . The apparatus of  claim 9 , wherein the divider forms floating metal piers. 
     
     
         11 . The apparatus of  claim 10 , wherein the gas inlets are disposed between the metal piers. 
     
     
         12 . The apparatus of  claim 9 , further comprising a weir to recover floating material. 
     
     
         13 . A method for recovering a target metal, comprising:
 (a) providing a cathode in electrical contact with a molten salt;   (b) providing an anode in electrical contact with the molten salt;   (c) dissolving an oxide of a target metal into the molten salt to form a molten salt and metal ion mixture;   (d) establishing an electrical potential between the cathode and the anode to form target metal at the cathode;   (e) bubbling a gas through the molten salt and metal ion mixture to form a gas and metal vapor mixture, the gas and metal vapor mixture comprising target metal vapors comprised at least in part by a portion of the target metal formed at the cathode; and   (f) condensing at least a portion of the target metal vapors.   
     
     
         14 . The method of  claim 13 , wherein the bubbling the gas through the molten salt and metal ion mixture comprises bubbling the gas in immediate proximity to the cathode. 
     
     
         15 . The method of  claim 13 , wherein the bubbling the gas through the molten salt and metal ion mixture comprises providing the gas through at least one opening in the cathode. 
     
     
         16 . The method of  claim 13 , wherein the bubbling the gas through the molten salt and metal ion mixture comprises providing the gas across a current path through the molten salt between the cathode and the anode. 
     
     
         17 . The method of  claim 13 , wherein the gas is inert. 
     
     
         18 . The method of  claim 13 , wherein the gas is argon. 
     
     
         19 . The method of  claim 13 , wherein the reduced metal first forms as a dilute vapor in the gas. 
     
     
         20 . The method of  claim 13 , further comprising measuring the quantity of target metal in the molten salt. 
     
     
         21 . The method of  claim 13 , further comprising providing a SOM between the cathode and the anode. 
     
     
         22 . The method of  claim 13 , wherein the oxide of the target metal further comprises at least one contaminant metal. 
     
     
         23 . The method of  claim 13 , wherein the target metal comprises magnesium, calcium or a lanthanide. 
     
     
         24 . The method of  claim 13 , wherein the target metal comprises magnesium, calcium, or samarium. 
     
     
         25 . The method of  claim 13 , wherein the target metal is magnesium. 
     
     
         26 . An apparatus for recovering a target metal, comprising:
 (a) a container for holding a molten salt;   (b) a cathode disposed to be in electrical contact with the molten salt when the molten salt is disposed in the container;   (c) an oxide ion-conducting membrane disposed to be in ion-conducting contact with the molten salt when the molten salt is disposed in the container;   (d) an anode in electrical contact with the oxide ion-conducting membrane;   (e) a power source for generating an electric potential between the anode and the cathode;   (f) a gas inlet having at least one end disposed within the container to be below a level of the molten salt when the molten salt is disposed in the container; and   (g) a gas outlet in fluid communication with a volume defined by the container.   
     
     
         27 . The apparatus of  claim 26 , wherein the at least one end of the gas inlet is in immediate proximity to the cathode. 
     
     
         28 . The apparatus of  claim 26 , wherein the cathode comprises the at least one end of the gas inlet. 
     
     
         29 . The apparatus of  claim 26 , wherein the at least one end of the gas inlet is disposed in the container to form gas bubbles in the molten salt, when the salt is disposed in the container, across a current path through the molten salt between the cathode and the anode. 
     
     
         30 . The apparatus of  claim 26 , wherein the gas inlet is a nozzle. 
     
     
         31 . The apparatus of  claim 26 , wherein the gas inlet is disposed at the bottom of the container. 
     
     
         32 . The apparatus of  claim 26 , wherein the cathode forms at least portion of container. 
     
     
         33 . A method for recovering a target metal, comprising:
 (a) providing a molten salt;   (b) dissolving a portion of a mixed metal scrap into the molten salt to form a molten salt and metal mixture, the mixed metal scrap comprising a target metal species and at least one contaminant metal species;   (c) reducing a pressure of the molten salt and metal mixture to remove, as vapors of the target metal, at least a portion of the target metal species dissolved in the molten salt and metal mixture; and   (d) recovering at least a portion of the target metal vapors.   
     
     
         34 . The method of  claim 33 , wherein the reducing a pressure of the molten salt and metal mixture comprises creating a partial vacuum in an atmosphere overlying the molten salt and metal mixture. 
     
     
         35 . The method of  claim 33 , wherein the mixed metal scrap comprises an oxide of the target metal. 
     
     
         36 . The method of  claim 33 , wherein the dissolving step comprises melting the scrap metal mixture. 
     
     
         37 . The method of  claim 33 , further comprising providing SOM elements and performing SOM electrolysis. 
     
     
         38 . The method of  claim 33 , further comprising dissolving an oxide of a second metal subsequent to production of at least some of the first metal in the salt. 
     
     
         39 . The method of  claim 33 , wherein the target metal comprises magnesium, calcium or a lanthanide. 
     
     
         40 . The method of  claim 33 , wherein the target metal comprises magnesium, calcium, or samarium. 
     
     
         41 . The method of  claim 33 , wherein the target metal is magnesium. 
     
     
         42 . An apparatus for recovering a target metal, comprising:
 (a) a container for holding a molten salt;   (b) a cathode disposed to be in electrical contact with the molten salt when the molten salt is disposed in the container;   (c) an oxide ion-conducting membrane disposed to be in ion-conducting contact with the molten salt when the molten salt is disposed in the container;   (d) an anode in electrical contact with the oxide ion-conducting membrane;   (e) a power source for generating an electric potential between the anode and the cathode;   (f) a gas outlet in fluid communication with a volume defined by the container;   (g) a condenser in fluid communication with the gas outlet for condensing at least a portion of the target metal vapor in the gas stream exiting the container; and   (h) a vacuum source in fluid communication with the gas outlet and/or the container for creating at least a partial vacuum in the volume defined by the container.   
     
     
         43 . A method for recovering a metal from an oxide of said metal, comprising:
 (a) providing a cathode in electrical contact with a molten salt;   (b) providing an anode in electrical contact with the molten salt;   (c) dissolving an oxide of a first metal into the molten salt to form a molten salt and metal ion mixture;   (d) establishing an electrical potential between the cathode and the anode to form first metal at the cathode;   (e) dissolving an oxide of a second metal into the molten salt, the second metal being more electronegative than the first metal, and the second metal being less soluble in the molten salt than the first metal;   (f) subsequent to dissolving the oxide of the second metal into the molten salt, establishing an electrical potential between the cathode and the anode to form first metal at the cathode; and   (g) recovering at least a portion of the first metal formed at the cathode.   
     
     
         44 . The method of  claim 43 , wherein the oxide of the second metal comprises nickel oxide. 
     
     
         45 . The method of  claim 43 , wherein the metal charge comprises contaminant metals and/or the first metal. 
     
     
         46 . The method of  claim 43 , wherein the first metal comprises magnesium, calcium or a lanthanide. 
     
     
         47 . The method of  claim 43 , wherein the first metal comprises magnesium, calcium, or samarium. 
     
     
         48 . The method of  claim 43 , wherein the first metal is magnesium.