Systems and methods for purifying aluminum

Abstract

The application is directed towards systems and methods for aluminum purification. A system, comprising: a cell defining a chamber having upper portion and lower portion; the lower portion including a cathode molten material collection area; an anode structure disposed in the upper portion vertically aligned above the lower portion; a cathode structure disposed in the upper portion vertically aligned above the cathode molten material collection area; and a liquid electrolyte within the chamber in fluid communication with the anode structure and the cathode structure, the liquid electrolyte having electrolyte density; the anode structure is configured to receive impure aluminum having impure aluminum density greater than the electrolyte density, and the cathode structure captures purified aluminum having purified aluminum density greater than the electrolyte density, the cathode structure defining a cathode flow path along which purified aluminum can flow.

1 . An aluminum purification system comprising:
 a cell defining a chamber having an upper portion and a lower portion;   the lower portion including an anode molten material collection area and a cathode molten material collection area defined therein;   an anode structure disposed in the upper portion of the chamber vertically aligned above the lower portion;   a cathode structure disposed in the upper portion of the chamber vertically aligned above the cathode molten material collection area; and   a liquid electrolyte within the chamber in fluid communication with the anode structure and the cathode structure, the liquid electrolyte having an electrolyte density;   wherein the anode structure is configured to receive impure aluminum in a molten state having an impure aluminum density greater than the electrolyte density and wherein the anode structure defines an anode flow path along which impure aluminum in a molten state can flow from the upper portion to the anode molten material collection area, and   further wherein the cathode structure is configured to capture purified aluminum in a molten state having a purified aluminum density greater than the electrolyte density from the impure aluminum through the liquid electrolyte, the cathode structure further defining a cathode flow path along which purified aluminum can flow from the upper portion to the cathode molten material collection area.   
     
     
         2 . The aluminum purification system of  claim 1 , wherein the anode structure includes a first anode structure portion and a second anode structure portion and an anode reservoir therebetween, and wherein the anode structure is configured to receive the impure aluminum in the anode reservoir. 
     
     
         3 . The aluminum purification system of  claim 2 , wherein a first side of the second anode structure portion is in fluid communication with the impure aluminum and a second side of the second anode structure portion is in fluid communication with the liquid electrolyte. 
     
     
         4 . The aluminum purification system of  claim 1 , wherein the anode structure is vertically aligned above the anode molten material collection area. 
     
     
         5 . The aluminum purification system of  claim 1 , wherein the cathode molten material collection area is separated from the anode molten material collection area by a partition disposed therebetween. 
     
     
         6 . The aluminum purification system of  claim 2 , wherein the anode flow path extends from the anode reservoir through the second anode structure portion to the anode molten material collection area. 
     
     
         7 . The aluminum purification system of  claim 2 , wherein the second anode structure portion comprises at least one of porous carbon material, graphite, carbon fiber cloth, porous TiB 2 , felt, and foam. 
     
     
         8 . The aluminum purification system of  claim 1 , wherein the cathode structure comprises one or more grooves defined therein. 
     
     
         9 . The aluminum purification system of  claim 1 , wherein the liquid electrolyte comprises LiF and AlF3. 
     
     
         10 . The aluminum purification system of  claim 1 , wherein the liquid electrolyte further comprises NaF, KF, and/or CaF 2 . 
     
     
         11 . The aluminum purification system of  claim 1 , wherein the liquid electrolyte has a density of less than about 2.7 g/cm 3 . 
     
     
         12 . The aluminum purification system of  claim 1 , wherein the cathode structure is configured to capture the purified aluminum at an energy consumption of from about 1.5 to 7 kWh/kg of purified aluminum captured at the cathode structure. 
     
     
         13 . The aluminum purification system of  claim 1 , wherein the distance between the anode structure and the cathode structure is between about 2 mm and about 5 cm. 
     
     
         14 . The aluminum purification system of  claim 5 , wherein an interface is defined between the liquid electrolyte and molten aluminum contained in each of the anode molten material collection area and the cathode molten material collection area, and wherein the partition extends within the chamber from a bottom of the cell to a height above the interface. 
     
     
         15 . The aluminum purification system of  claim 5 , wherein the liquid electrolyte has an upper surface, and wherein the partition does not contact the upper surface of the liquid electrolyte. 
     
     
         16 . The aluminum purification system of  claim 1 , wherein an interface is defined between the liquid electrolyte and molten aluminum contained in the cathode molten material collection area, the interface below the cathode structure. 
     
     
         17 . The aluminum purification system of any of  claim 1 , wherein the liquid electrolyte flows freely between the anode structure and the cathode structure. 
     
     
         18 . A method of aluminum purification comprising:
 operating a purification system, the purification system comprising:   a cell defining a chamber having an upper portion and a lower portion;   the lower portion including an anode molten material collection area and a cathode molten material collection area defined therein;   an anode structure disposed in the upper portion of the chamber vertically aligned above the lower portion;   a cathode structure disposed in the upper portion of the chamber vertically aligned above the molten material collection area; and   a liquid electrolyte within the chamber in fluid communication with the anode structure and the cathode structure, the liquid electrolyte having an electrolyte density;   introducing impure aluminum in a molten state having an impure aluminum density greater than the electrolyte density into the chamber to be received by the anode structure, the anode structure defining an anode flow path along which impure aluminum in a molten state can flow from the upper portion to the anode molten material collection area;   capturing purified aluminum in a molten state having a purified aluminum density greater than the electrolyte density at the cathode structure from the impure aluminum through the liquid electrolyte, the cathode structure defining a cathode flow path along which the purified aluminum can flow from the upper portion to the cathode molten material collection area;   collecting in the cathode molten material collection area purified aluminum released from the cathode structure.   
     
     
         19 . The method of aluminum purification of  claim 18 , further comprising capturing at the cathode structure purified aluminum at an energy consumption of from about 1.5 to 7 kWh/kg of purified aluminum captured at the cathode structure. 
     
     
         20 . The method of aluminum purification of  claim 18 , wherein the impure aluminum is not alloyed with copper before the impure aluminum is introduced into the chamber. 
     
     
         21 . The method of aluminum purification of  claim 18 , wherein introducing impure aluminum includes continuously introducing impure aluminum to be received by the anode structure. 
     
     
         22 . The method of aluminum purification of  claim 18 , further comprising transferring impure aluminum from the anode structure to a second cell, the transferred impure aluminum to be received by a second anode structure. 
     
     
         23 . The method of aluminum purification of  claim 18 , further comprising transferring impure aluminum from the anode molten material collection area to a second cell, the transferred impure aluminum to be received by a second anode structure. 
     
     
         24 . The method of  claim 23 , wherein the first cell has a first cell temperature and the second cell has a second cell temperature, the second cell temperature higher than the first cell temperature. 
     
     
         25 . An aluminum purification system comprising:
 a cell defining a chamber having an upper portion and a lower portion;   the lower portion including a cathode molten material collection area defined therein;   an anode structure disposed in the upper portion of the chamber vertically aligned above the lower portion;   a cathode structure disposed in the upper portion of the chamber vertically oriented above the cathode molten material collection area; and   a liquid electrolyte within the chamber in fluid communication with the anode structure and the cathode structure, the liquid electrolyte comprising LiF and AlF3 and having an electrolyte density;   wherein the anode structure is configured to receive impure aluminum in a molten state having an impure aluminum density greater than the electrolyte density, and further wherein the cathode structure is configured to capture purified aluminum in a molten state having a purified aluminum density greater than the electrolyte density from the impure aluminum through the liquid electrolyte, the cathode structure further defining a cathode flow path along which purified aluminum can flow from the upper portion to the cathode molten material collection area.   
     
     
         26 . The aluminum purification system of  claim 25 , wherein the liquid electrolyte further comprises NaF, KF, and/or CaF 2 . 
     
     
         27 . The aluminum purification system of  claim 25 , wherein the liquid electrolyte has a density of less than about 2.7 g/cm 3 .