Systems and methods for recovering aluminum scrap and associated products

Abstract

The present application relates to products and methods related to aluminum scrap recovery. The method comprises: (a) adding a feedstock to an aluminum purification unit, wherein the feedstock comprises aluminum scrap; (b) purifying the feedstock, thereby producing a purified aluminum stream and a residue stream; (c) separating the components of the residue stream, thereby producing at least a first by-product stream and a second by-product stream; and (d) mixing at least a portion of the first byproduct stream with at least a portion of the purified aluminum from the purified aluminum stream to produce an aluminum alloy product.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 437,251, filed on January 5, 2023, entitled “Systems and Methods of Recycling Aluminum Scrap and Associated Products,” which is incorporated herein by reference in its entirety. Background Art

[0003] Traditionally, aluminum metal is made by converting aluminum oxide (Al2O3), which is typically derived from bauxite. The conversion of aluminum oxide to aluminum is typically performed in an electrolytic cell by passing an electric current through an electrolyte having aluminum oxide and cryolite. Carbon from the carbon anode reacts with the oxygen component in the aluminum oxide to produce carbon dioxide, which is discharged from the electrolytic cell, leaving molten aluminum as a by-product. The molten aluminum accumulates at the bottom of the electrolytic cell and is subsequently removed as relatively pure metallic aluminum. Various efforts have been made to purify metallic aluminum, including the "Hoopes process" (see U.S. Patent No. 1,534,315) and those described in co-owned International Patent Application WO2016 / 130823. Summary of the Invention

[0004] Broadly speaking, the disclosure relates to methods and systems for purifying aluminum scrap in an aluminum purification unit, and products made therefrom. The continuous accumulation of impurities in aluminum scrap can pose a challenge to aluminum recycling. In some cases, recycled aluminum scrap can only be used in products that require increasingly smaller amounts of aluminum. "Downcycling" to lower value products results in reduced product purity - an unsustainable process. Although aluminum is highly recyclable, there are currently no commercially viable processes that can remove unwanted impurities from aluminum scrap. The disclosure as a whole relates to the purification of aluminum scrap that can be recycled without sacrificing the purity level of the purified aluminum product. Aluminum recycling can also reduce energy consumption and carbon dioxide equivalent (CO2 equivalent) compared to traditional alumina smelting processes. 2e ) discharge. In one embodiment, a closed loop process can be used. In another embodiment, an open loop process is used.

[0005] In one approach, the method includes: (a) adding a feedstock to an aluminum purification unit, wherein the feedstock includes aluminum scrap; (b) purifying the feedstock, thereby producing a purified aluminum stream and a residue stream; (c) separating components of the residue stream, thereby producing at least a first byproduct stream and a second byproduct stream; and (d) combining at least a portion of the first byproduct stream with at least a portion of the purified aluminum from the purified aluminum stream to produce an aluminum alloy product. The resulting aluminum alloy product can have a predetermined composition and / or product form suitable for commercial use. Thus, aluminum scrap can be purified and one or more of its components can be reused to produce a commercially viable product.

[0006] As described above, the method may include adding a feedstock to an aluminum purification unit. In some embodiments, the feedstock comprises at least 50% Al (aluminum) by weight. In one embodiment, the feedstock comprises at least 55% Al by weight. In another embodiment, the feedstock comprises at least 60% Al by weight. In yet another embodiment, the feedstock comprises at least 65% Al by weight. In another embodiment, the feedstock comprises at least 70% Al by weight. In yet another embodiment, the feedstock comprises at least 75% Al by weight. In another embodiment, the feedstock comprises at least 80% Al by weight. In yet another embodiment, the feedstock comprises at least 85% Al by weight. In another embodiment, the feedstock comprises at least 90% Al by weight. In yet another embodiment, the feedstock comprises at least 95% Al by weight. In another embodiment, the feedstock comprises at least 99% Al by weight. In yet another embodiment, the feedstock comprises at least 99.5% Al by weight.

[0007] In one method, the feedstock may comprise no more than 99.5% Al by weight. In one embodiment, the feedstock comprises no more than 99% Al by weight. In another embodiment, the feedstock comprises no more than 98% Al by weight. In yet another embodiment, the feedstock comprises no more than 97% Al by weight. In another embodiment, the feedstock comprises no more than 96% Al by weight. In yet another embodiment, the feedstock comprises no more than 95% Al by weight. In another embodiment, the feedstock comprises no more than 94% Al by weight. In yet another embodiment, the feedstock comprises no more than 93% Al by weight. In another embodiment, the feedstock comprises no more than 92% Al by weight. In yet another embodiment, the feedstock comprises no more than 91% Al by weight. In another embodiment, the feedstock comprises no more than 90% Al by weight. In yet another embodiment, the feedstock comprises no more than 85% Al by weight. In another embodiment, the feedstock comprises no more than 80% Al by weight. In yet another embodiment, the feedstock comprises no more than 75% Al by weight. In another embodiment, the feedstock comprises no more than 70% Al by weight. In yet another embodiment, the feedstock comprises no greater than 65 wt% Al. In another embodiment, the feedstock comprises no greater than 60 wt% Al. In yet another embodiment, the feedstock comprises no greater than 55 wt% Al.

[0008] In one embodiment, the feedstock comprises 50 to 99 wt% Al. In another embodiment, the feedstock comprises 55 to 98 wt% Al. In yet another embodiment, the feedstock comprises 60 to 97 wt% Al. In another embodiment, the feedstock comprises 65 to 96 wt% Al. In yet another embodiment, the feedstock comprises 65 to 95 wt% Al.

[0009] In one embodiment, the feedstock comprises no more than 5% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock comprises no more than 4% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock comprises no more than 3% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock comprises no more than 2% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock comprises no more than 1% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock comprises no more than 0.5% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock comprises no more than 0.25% by weight aluminum oxide (Al2O3).

[0010] In another embodiment, the feedstock includes no greater than 0.1 wt. % alumina (Al2O3).

[0011] As described above, the feedstock may include aluminum scrap. The aluminum scrap may constitute part or all of the feedstock. Thus, the aluminum content of the feedstock may be based on the amount of aluminum in the aluminum scrap. In one embodiment, the aluminum scrap comprises at least 5% by weight of Al of the feedstock (i.e., the aluminum content of the aluminum scrap accounts for at least 5% by weight of the total aluminum content of the feedstock). In one embodiment, the aluminum scrap comprises at least 10% by weight of Al of the feedstock. In another embodiment, the aluminum scrap comprises at least 15% by weight of Al of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 20% by weight of Al of the feedstock. In another embodiment, the aluminum scrap comprises at least 25% by weight of Al of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 30% by weight of Al of the feedstock. In another embodiment, the aluminum scrap comprises at least 35% by weight of Al of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 40% by weight of Al of the feedstock. In another embodiment, the aluminum scrap comprises at least 45% by weight of Al of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 50% by weight of Al of the feedstock. In another embodiment, the aluminum scrap comprises at least 55% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 60% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 65% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 70% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 75% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 80% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 85% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 90% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 95% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 99% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 99.5% Al by weight of the feedstock. In yet another embodiment, the aluminum scrap comprises at least 100% Al by weight of the feedstock (i.e., the aluminum content of the aluminum scrap comprises all of the aluminum content of the feedstock).

[0012] As described above, the method can include a purification step (b) in which the feedstock is purified (e.g., in an aluminum purification unit), thereby producing a purified aluminum stream and a residue stream. In one embodiment, the purification step comprises passing an electric current through at least one anode, through the electrolytic bath, and into at least one cathode. In one embodiment, the density of the electrolyte is greater than the density of the purified aluminum. In one embodiment, the purified aluminum accumulates above the electrolyte. In one embodiment, the purified aluminum forms a purified aluminum layer. In one embodiment, the purified aluminum layer is disposed above the electrolyte in the aluminum purification unit.

[0013] The purified aluminum stream typically comprises more aluminum than the feedstock. In one approach, the purified aluminum stream comprises at least 95% Al by weight up to 99.999% Al by weight. In one embodiment, the purified aluminum stream comprises at least 95.5% Al by weight. In another embodiment, the purified aluminum stream comprises at least 96% Al by weight. In yet another embodiment, the purified aluminum stream comprises at least 96.5% Al by weight. In another embodiment, the purified aluminum stream comprises at least 97% Al by weight. In yet another embodiment, the purified aluminum stream comprises at least 97.5% Al by weight. In another embodiment, the purified aluminum stream comprises at least 98% Al by weight. In yet another embodiment, the purified aluminum stream comprises at least 98.5% Al by weight. In another embodiment, the purified aluminum stream comprises at least 99% Al by weight. In yet another embodiment, the purified aluminum stream comprises at least 99.5% Al by weight. In another embodiment, the purified aluminum stream comprises at least 99.75% Al by weight. In yet another embodiment, the purified aluminum stream comprises at least 99.8% Al by weight. In another embodiment, the purified aluminum stream comprises at least 99.85 wt% Al. In yet another embodiment, the purified aluminum stream comprises at least 99.9 wt% Al. In another embodiment, the purified aluminum stream comprises at least 99.95 wt% Al.

[0014] As described above, a residual stream may be produced due to the purification step. The residual stream typically comprises less aluminum than the raw material. In some embodiments, the residual stream comprises no more than 50% by weight Al. In one embodiment, the residual stream comprises no more than 45% by weight Al. In another embodiment, the residual stream comprises no more than 40% by weight Al. In yet another embodiment, the residual stream comprises no more than 35% by weight Al. In another embodiment, the residual stream comprises no more than 30% by weight Al. In yet another embodiment, the residual stream comprises no more than 25% by weight Al. In another embodiment, the residual stream comprises no more than 20% by weight Al. In yet another embodiment, the residual stream comprises no more than 15% by weight Al. In another embodiment, the residual stream comprises no more than 10% by weight Al. In yet another embodiment, the residual stream comprises no more than 8% by weight Al. In another embodiment, the residual stream comprises no more than 5% by weight Al. In yet another embodiment, the residual stream comprises no more than 3% by weight Al. In another embodiment, the residual stream comprises no more than 1% by weight Al.

[0015] In one embodiment, the residual stream comprises at least 3% by weight of Si (silicon). In one embodiment, the residual stream comprises at least 3% by weight of Fe (iron). In one embodiment, the residual stream comprises both at least 3% by weight of Si and at least 3% by weight of Fe. In one embodiment, the residual stream comprises no more than 99% by weight of Si. In another embodiment, the residual stream comprises no more than 95% by weight of Si. In one embodiment, the residual stream comprises no more than 99% by weight of Fe. In one embodiment, the residual stream comprises no more than 95% by weight of Fe.

[0016] As described above, the method may include (c) separating the components of the residual stream, thereby producing at least a first by-product stream and a second by-product stream. The method may also include (d) mixing at least a portion of the first by-product stream with at least a portion of the purified aluminum from the purified aluminum stream to produce an aluminum alloy product. In some embodiments, the aluminum alloy product has a composition consistent with one of the 1xxx-8xxx aluminum alloys defined in the document "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" (international alloy names and chemical composition limits for wrought aluminum and wrought aluminum alloys) by the Aluminum Association. In some embodiments, the disclosure relates to a method, wherein the aluminum alloy product has a composition consistent with one of the 1xx-8xx aluminum alloys defined in the document "Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot" (names and chemical composition limits for aluminum alloy castings and ingots) by the Aluminum Association.

[0017] In one embodiment, at least a portion of the first byproduct stream is used in combination with a purified aluminum stream to produce an aluminum alloy product. In one embodiment, most or all of the first byproduct stream is combined with a purified aluminum stream to produce an aluminum alloy product.

[0018] Additional by-product streams can also be combined with the purified aluminum stream to produce an aluminum alloy product. In one embodiment, a portion of both the first by-product stream and the second by-product stream are combined with the purified aluminum stream to form an aluminum alloy product. In another embodiment, a portion of the first by-product stream is combined with a portion of the purified aluminum stream to form a first aluminum alloy product. Relatedly, a portion of the second by-product stream can be combined with a portion of the purified aluminum stream to form a second aluminum alloy product, the second aluminum alloy product having a composition different from that of the first aluminum alloy product. The same principle applies to any third by-product stream and subsequent by-product streams that can be produced. Therefore, various customized aluminum alloy product compositions can be produced from aluminum scrap.

[0019] The by-product stream may include, for example, one or more of silicon, iron, zinc, copper, and manganese. In one embodiment, the first by-product stream and / or the second by-product stream include at least one of the following: at least 12 wt% Si, at least 3 wt% Mn, at least 3 wt% Fe, and combinations thereof. In one embodiment, the first by-product stream and / or the second by-product stream include at least 5% of at least one of the following: Si, Mn, Fe, Zn, Cu, and combinations thereof.

[0020] In addition to or in lieu of using the first byproduct stream, the method may include using additional components to facilitate the production of a customized (predetermined) aluminum alloy product. In one embodiment, the method includes mixing additional components with the purified aluminum stream to facilitate the production of the aluminum alloy product. In one embodiment, the additional components include at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof. In one embodiment, the additional components include one or more aluminum scrap alloys (i.e., scrap comprising an aluminum alloy).

[0021] The first byproduct stream and / or the precursor stream may be used to facilitate production of the feedstock.In one embodiment, the method may include adding at least one of the first byproduct stream and / or the second byproduct stream to the precursor stream to produce the feedstock.

[0022] In one embodiment, the method includes adding a predetermined metal to the precursor stream. In one embodiment, the predetermined metal is at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof. In one embodiment, the predetermined metal is at least one of Cu, Ce, Cs, Sn, Zn, and combinations thereof. In one embodiment, the predetermined metal is Cu.

[0023] The produced aluminum alloy product may be in any suitable form, such as in the form of ingots, billets, powders, wires, strips, etc. Suitable wrought products (foils, sheets, plates, forgings, extrusions), shaped casting products (e.g., die-cast products), and additively manufactured products (e.g., 3D-printed products) may be produced from the aluminum alloy product.

[0024] Although the embodiments disclosed herein generally relate to the purification of aluminum, it is contemplated that embodiments of the disclosure are also applicable to the purification of other elements and / or compounds. For example, embodiments of the disclosure may alternatively or additionally relate to the purification of magnesium. In some embodiments, the systems, apparatus, and / or methods of the disclosure relate to a magnesium purification unit for producing purified magnesium from a magnesium feedstock. The foregoing embodiments are exemplary embodiments of the apparatus, system, or method of the disclosure and, therefore, should not be considered limiting of the scope of the disclosure, as the apparatus, system, and method of the disclosure may admit of other equally effective embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 One embodiment of a method for purifying a feedstock is shown.

[0026] Figure 2 One embodiment of a process flow diagram according to the disclosure is shown. DETAILED DESCRIPTION

[0027] Now refer to Figure 1 , discloses a non-limiting embodiment of a method 100 for purifying a feedstock. Step 110 includes adding the feedstock to an aluminum purification unit. Step 120 includes purifying the feedstock via the aluminum purification unit. Step 120 includes producing a purified aluminum stream and a residue stream. Step 130 includes extracting the purified aluminum stream. Step 140 includes extracting the residue stream. Step 150 (optional) includes separating the residue stream into by-product streams. Step 160 (optional) includes combining the purified aluminum stream (e.g., the stream extracted in step 130) and at least one by-product stream (e.g., a by-product stream separated from the residue stream extracted in step 140) to produce a predetermined aluminum alloy product stream. It should be understood that Figure 1 Some of these steps are shown with dashed boxes, indicating that these steps are optional.

[0028] As used herein, "aluminum feedstock" refers to a feedstock suitable for producing purified aluminum in an aluminum purification unit. The aluminum feedstock can have any suitable aluminum content. Typically, the aluminum feedstock will have at least 50% by weight aluminum, but in some embodiments, lower amounts of aluminum (e.g., at least 25% by weight Al) can be used in the aluminum feedstock. In some embodiments, the aluminum feedstock includes aluminum and at least one other metal (e.g., one or more of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc). In some embodiments, the aluminum feedstock includes a transition metal. In some embodiments, the aluminum feedstock is substantially free of aluminum oxide (Al2O3), as described herein.

[0029] As used herein, "purified aluminum" refers to a material having at least 95% aluminum by weight, as described herein.

[0030] Figure 2 A representative flow diagram of a process 200 according to the disclosure of some embodiments is shown. In the illustrated embodiment, process 200 includes adding a raw material 210 to a purification unit 212. In some embodiments, purification unit 212 is an aluminum purification unit. In some embodiments, raw material 210 includes aluminum scrap. Raw material 210 can be purified by purification unit 212. After purification, purification unit 212 produces a purified aluminum stream 214 and a residue stream 216. Purified aluminum stream 214 can be collected as purified aluminum product 250. Residue stream 216 can include impurities and / or other components not included in the purified aluminum stream. Residue stream 216 can be separated into one or more by-product streams (220, 222, 224). A by-product stream from residue stream 216 (e.g., a first by-product stream 220) can be mixed with purified aluminum stream 214 to form a predetermined aluminum alloy product (e.g., a first predetermined aluminum alloy product 232).

[0031] In some embodiments, feedstock 210 may be fed to purification unit 212. In some embodiments, feedstock 210 may be fed to the purification unit without modification (e.g., the feedstock is not mixed with other streams prior to introduction into purification unit 212). The feedstock may be obtained from an external source or may be obtained as a result of the operation of the purification unit. In some embodiments, at least a portion of feedstock 210 is precursor 242. In other embodiments, at least a portion of feedstock 210 is recycled residue 246.

[0032] The raw material 210 may be fed to the purification unit 212 in an amount required to produce a purified aluminum product. In some embodiments, adding the raw material 210 to the purification unit 212 includes continuously feeding the raw material 210 during operation of the purification unit 212. In some embodiments, adding the raw material 210 to the purification unit 212 includes periodically or intermittently adding the raw material 210 to the purification unit 212. In some embodiments, adding the raw material 210 to the purification unit 212 includes metering the raw material 210 into the purification unit 212 at a first feed rate. The first feed rate may remain constant or may vary, including stopping and starting the feeding of the raw material 210 to the purification unit 212.

[0033] Process 200 can include adding a byproduct stream (e.g., first byproduct stream 220) to feedstock 210 prior to introduction into purification unit 212. In some embodiments, process 200 includes adding at least one of first byproduct stream 220, second byproduct stream 222, and / or third byproduct stream 224 to precursor 242 to produce feedstock 210. It should be understood that while three byproduct streams are shown, any number of byproduct streams can be employed. Typically, at least two byproduct streams are utilized.

[0034] In some embodiments, feedstock 210 can be prepared by a step of mixing 240 at least two streams together. In some embodiments, at least a portion of feedstock 210 can be prepared by mixing at least two of the following streams: precursor 242, additional component 244, recovered residue 246, a byproduct stream (e.g., first byproduct stream 220), or any combination thereof. In other embodiments, feedstock 210 is not mixed with other sources and is used as received.

[0035] In some embodiments, additional component 244 includes a metal. In some embodiments, process 200 includes adding one or more predetermined metals to precursor 242 to produce at least a portion of feedstock 210. In some embodiments, the predetermined metal is at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof. In some embodiments, the predetermined metal is at least one of Cu, Ce, Cs, Sn, Zn, and combinations thereof. In some embodiments, the predetermined metal includes at least Cu. Precursor 242 can have the same composition as feedstock 210, as described herein.

[0036] In some embodiments, the feedstock 210 comprises at least 50 wt% Al. In one embodiment, the feedstock 210 comprises at least 55 wt% Al. In another embodiment, the feedstock 210 comprises at least 60 wt% Al. In yet another embodiment, the feedstock 210 comprises at least 65 wt% Al. In another embodiment, the feedstock 210 comprises at least 70 wt% Al. In yet another embodiment, the feedstock 210 comprises at least 75 wt% Al. In another embodiment, the feedstock 210 comprises at least 80 wt% Al. In yet another embodiment, the feedstock 210 comprises at least 85 wt% Al. In another embodiment, the feedstock 210 comprises at least 90 wt% Al. In yet another embodiment, the feedstock 210 comprises at least 95 wt% Al. In another embodiment, the feedstock 210 comprises at least 99 wt% Al. In yet another embodiment, the feedstock 210 comprises at least 99.5 wt% Al.

[0037] In one approach, the feedstock 210 may include no greater than 99.5 wt% Al. In one embodiment, the feedstock 210 includes no greater than 99 wt% Al. In another embodiment, the feedstock 210 includes no greater than 98 wt% Al. In yet another embodiment, the feedstock 210 includes no greater than 97 wt% Al. In another embodiment, the feedstock 210 includes no greater than 96 wt% Al. In yet another embodiment, the feedstock 210 includes no greater than 95 wt% Al. In another embodiment, the feedstock 210 includes no greater than 94 wt% Al. In yet another embodiment, the feedstock 210 includes no greater than 93 wt% Al. In another embodiment, the feedstock 210 includes no greater than 92 wt% Al. In yet another embodiment, the feedstock 210 includes no greater than 91 wt% Al. In another embodiment, the feedstock 210 includes no greater than 90 wt% Al. In yet another embodiment, the feedstock 210 includes no greater than 85 wt% Al. In another embodiment, the feedstock 210 includes no greater than 80 wt% Al. In yet another embodiment, the feedstock 210 comprises no greater than 75 wt% Al. In another embodiment, the feedstock 210 comprises no greater than 70 wt% Al. In yet another embodiment, the feedstock 210 comprises no greater than 65 wt% Al. In another embodiment, the feedstock 210 comprises no greater than 60 wt% Al. In yet another embodiment, the feedstock 210 comprises no greater than 55 wt% Al.

[0038] In one embodiment, the feedstock 210 comprises 50% to 99% Al by weight. In another embodiment, the feedstock 210 comprises 55% to 98% Al by weight. In yet another embodiment, the feedstock 210 comprises 60% to 97% Al by weight. In another embodiment, the feedstock 210 comprises 65% to 96% Al by weight. In yet another embodiment, the feedstock 210 comprises 65% to 95% Al by weight.

[0039] In one embodiment, the feedstock 210 comprises no more than 5% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock 210 comprises no more than 4% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock 210 comprises no more than 3% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock 210 comprises no more than 2% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock 210 comprises no more than 1% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock 210 comprises no more than 0.5% by weight aluminum oxide (Al2O3). In yet another embodiment, the feedstock 210 comprises no more than 0.25% by weight aluminum oxide (Al2O3). In another embodiment, the feedstock 210 comprises no more than 0.1% by weight aluminum oxide (Al2O3).

[0040] The raw material 210 may include impurities. In some embodiments, the impurities of the raw material 210 may include Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, Cr, Cu, Fe, Mg, Mn, Ni, Si, Ti, Zn, and combinations thereof. In some embodiments, the impurities of the raw material 210 may include Cr, Cu, Fe, Mg, Mn, Ni, Si, Ti, Zn, and combinations thereof. In some embodiments, the raw material 210 may have aluminum and up to 2% by weight of Mg and other impurities. In some embodiments, the raw material 210 includes 0.5% to 50.0% by weight of the raw material 210 of impurities. In some embodiments, the raw material 210 includes 5.0% to 50.0% by weight of the raw material 210 of impurities. In some embodiments, the raw material 210 includes 10.0% to 50.0% by weight of the raw material 210 of impurities. In some embodiments, the raw material 210 comprises impurities in an amount of 15.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 20.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 25.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 30.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 35.0% to 50.0% by weight of the raw material 210. In some embodiments, the aluminum raw material 210 comprises impurities in an amount of 40.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 45.0% to 50.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises impurities in an amount of 0.5% to 45.0% by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 40.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 35.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 30.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 25.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 20.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 15.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 10.0% impurities by weight of the raw material 210. In some embodiments, the raw material 210 comprises between 0.5% and 5.0% impurities by weight of the raw material 210.

[0041] In some embodiments, the raw material 210 comprises aluminum scrap. In some embodiments, the aluminum scrap is aluminum alloy scrap, i.e., scrap comprising, consisting essentially of, or consisting of one or more aluminum alloys. In some embodiments, the aluminum alloy scrap comprises at least one of 1xxx-8xxx aluminum alloys and combinations thereof. In one embodiment, the aluminum alloy scrap comprises at least 1xxx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 2xxx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 3xxx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 4xxx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 5xxx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 6xxx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 7xxx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 8xxx series aluminum alloy scrap.

[0042] In some embodiments, the aluminum alloy scrap comprises at least one of 1xx-8xx aluminum alloys and combinations thereof. In one embodiment, the aluminum alloy scrap comprises at least 1xx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 2xx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 3xx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 4xx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 5xx series aluminum alloy scrap. In yet another embodiment, the aluminum alloy scrap comprises at least 7xx series aluminum alloy scrap. In another embodiment, the aluminum alloy scrap comprises at least 8xx series aluminum alloy scrap.

[0043] In some embodiments, the disclosure relates to a method wherein the aluminum scrap comprises at least 5% Al by weight of the feedstock 210 (i.e., the aluminum content of the aluminum scrap is at least 5% by weight of the total aluminum content of the feedstock 210). In one embodiment, the aluminum scrap comprises at least 10% Al by weight of the feedstock 210. In another embodiment, the aluminum scrap comprises at least 15% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 20% Al by weight of the feedstock 210. In another embodiment, the aluminum scrap comprises at least 25% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 30% Al by weight of the feedstock 210. In another embodiment, the aluminum scrap comprises at least 35% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 40% Al by weight of the feedstock 210. In another embodiment, the aluminum scrap comprises at least 45% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 50% Al by weight of the feedstock 210. In another embodiment, the aluminum scrap comprises at least 55% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 60% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 65% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 70% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 75% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 80% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 85% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 90% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 95% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 99% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 99.5% Al by weight of the feedstock 210. In yet another embodiment, the aluminum scrap comprises at least 100 wt. % Al of the feedstock 210 (ie, the aluminum content of the aluminum scrap comprises all of the aluminum content of the feedstock 210).

[0044] In some embodiments, additional components 244 such as additives (e.g., Cu, Ce, Cs, Sn, Zn, and combinations thereof) may be added to the feedstock 210 to increase or maintain its density, which may at least partially facilitate retaining / maintaining the metal of the feedstock 210 at or near the bottom of the purification unit 212 at the molten metal pad.

[0045] In some embodiments, the raw material 210 includes at least copper. In these embodiments, the raw material may include at least 1% by weight Cu up to 50% by weight Cu. In one embodiment, the raw material includes at least 5% by weight Cu. In another embodiment, the raw material 210 includes at least 10% by weight Cu. In yet another embodiment, the raw material 210 includes at least 15% by weight Cu. In another embodiment, the raw material 210 includes at least 20% by weight Cu. In yet another embodiment, the raw material 210 includes at least 25% by weight Cu. In another embodiment, the raw material 210 includes at least 30% by weight Cu. In yet another embodiment, the raw material 210 includes at least 35% by weight Cu. In another embodiment, the raw material 210 includes at least 40% by weight Cu. In yet another embodiment, the raw material 210 includes at least 45% by weight Cu.

[0046] In some embodiments, the raw material 210 includes at least cerium. In these embodiments, the raw material may include at least 1% by weight of Ce up to 50% by weight of Ce. In one embodiment, the raw material includes at least 5% by weight of Ce. In another embodiment, the raw material 210 includes at least 10% by weight of Ce. In yet another embodiment, the raw material 210 includes at least 15% by weight of Ce. In another embodiment, the raw material 210 includes at least 20% by weight of Ce. In yet another embodiment, the raw material 210 includes at least 25% by weight of Ce. In another embodiment, the raw material 210 includes at least 30% by weight of Ce. In yet another embodiment, the raw material 210 includes at least 35% by weight of Ce. In another embodiment, the raw material 210 includes at least 40% by weight of Ce. In yet another embodiment, the raw material 210 includes at least 45% by weight of Ce.

[0047] In some embodiments, the raw material 210 includes at least cesium. In these embodiments, the raw material may include at least 1% by weight Cs up to 50% by weight Cs. In one embodiment, the raw material includes at least 5% by weight Cs. In another embodiment, the raw material 210 includes at least 10% by weight Cs. In yet another embodiment, the raw material 210 includes at least 15% by weight Cs. In another embodiment, the raw material 210 includes at least 20% by weight Cs. In yet another embodiment, the raw material 210 includes at least 25% by weight Cs. In another embodiment, the raw material 210 includes at least 30% by weight Cs. In yet another embodiment, the raw material 210 includes at least 35% by weight Cs. In another embodiment, the raw material 210 includes at least 40% by weight Cs. In yet another embodiment, the raw material 210 includes at least 45% by weight Cs.

[0048] In some embodiments, the raw material 210 includes at least tin. In these embodiments, the raw material may include at least 1% Sn by weight up to 50% Sn by weight. In one embodiment, the raw material includes at least 5% Sn by weight. In another embodiment, the raw material 210 includes at least 10% Sn by weight. In yet another embodiment, the raw material 210 includes at least 15% Sn by weight. In another embodiment, the raw material 210 includes at least 20% Sn by weight. In yet another embodiment, the raw material 210 includes at least 25% Sn by weight. In another embodiment, the raw material 210 includes at least 30% Sn by weight. In yet another embodiment, the raw material 210 includes at least 35% Sn by weight. In another embodiment, the raw material 210 includes at least 40% Sn by weight. In yet another embodiment, the raw material 210 includes at least 45% Sn by weight.

[0049] In some embodiments, the raw material 210 includes at least copper. In these embodiments, the raw material may include at least 1% Zn by weight up to 50% Zn by weight. In one embodiment, the raw material includes at least 5% Zn by weight. In another embodiment, the raw material 210 includes at least 10% Zn by weight. In yet another embodiment, the raw material 210 includes at least 15% Zn by weight. In another embodiment, the raw material 210 includes at least 20% Zn by weight. In yet another embodiment, the raw material 210 includes at least 25% Zn by weight. In another embodiment, the raw material 210 includes at least 30% Zn by weight. In yet another embodiment, the raw material 210 includes at least 35% Zn by weight. In another embodiment, the raw material 210 includes at least 40% Zn by weight. In yet another embodiment, the raw material 210 includes at least 45% Zn by weight.

[0050] In some embodiments, the purified aluminum stream 214 is not mixed with any other streams. The purified aluminum stream 214 can be the same as the purified aluminum product 250. In some embodiments, additional components (e.g., additional component 238 or additional component 244) can be mixed with the purified aluminum stream 214 to produce the purified aluminum product 250 and / or the aluminum alloy product 236.

[0051] In some embodiments, the purified aluminum product 250 comprises at least 95% Al by weight and up to 99.999% Al by weight. In some embodiments, the aluminum purity of the purified aluminum product 250 is at least 99.5% Al by weight and up to 99.999% Al by weight. In some embodiments, the aluminum purity of the purified aluminum product 250 is at least 99.9% Al by weight and up to 99.999% Al by weight. In some embodiments, the aluminum purity of the purified aluminum product 250 is at least 99.9% Al by weight and up to 99.999% Al by weight. In some embodiments, the aluminum purity of the purified aluminum product 250 is at least 99.98% Al by weight and up to 99.999% Al by weight. In one embodiment, the purified aluminum product comprises at least 95.5% Al by weight. In another embodiment, the purified aluminum product comprises at least 96% Al by weight. In yet another embodiment, the purified aluminum product comprises at least 96.5% Al by weight. In another embodiment, the purified aluminum product comprises at least 97% Al by weight. In yet another embodiment, the purified aluminum product comprises at least 97.5% Al by weight. In another embodiment, the purified aluminum product comprises at least 98% Al by weight. In yet another embodiment, the purified aluminum product comprises at least 98.5% by weight Al. In another embodiment, the purified aluminum product comprises at least 99% by weight Al. In yet another embodiment, the purified aluminum product comprises at least 99.5% by weight Al. In another embodiment, the purified aluminum product comprises at least 99.75% by weight Al. In yet another embodiment, the purified aluminum product comprises at least 99.8% by weight Al. In another embodiment, the purified aluminum product comprises at least 99.85% by weight Al. In yet another embodiment, the purified aluminum product comprises at least 99.9% by weight Al. In another embodiment, the purified aluminum product comprises at least 99.95% by weight Al.

[0052] In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 1 kWh / kg to 15 kWh / kg of purified aluminum. In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 1 kWh / kg to 10 kWh / kg of purified aluminum. In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 1 kWh / kg to 8 kWh / kg of purified aluminum. In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 1 kWh / kg to 6 kWh / kg of purified aluminum. In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 1 kWh / kg to 4 kWh / kg of purified aluminum. In some embodiments, the purified aluminum product 250 can be produced via the purification unit 212 at an energy efficiency of 5 kWh / kg to 15 kWh / kg of purified aluminum. In some embodiments, purified aluminum product 250 may be produced at an energy efficiency of 10 to 15 kWh / kg of purified aluminum via purification unit 212. In some embodiments, purified aluminum product 250 may be produced at an energy efficiency of 12 to 15 kWh / kg of purified aluminum via purification unit 212.

[0053] In some embodiments, purifying feedstock 210 and producing purified aluminum stream 214 and residue stream 216 includes passing an electrical current through at least one anode, through an electrolyte (e.g., an electrolytic bath), and into at least one cathode. In some embodiments, passing an electrical current includes passing a direct current (DC) from the anode through the electrolyte to the cathode. In some embodiments, the anode and cathode can be partially disposed in the electrolyte, and the anode can be partially disposed in the molten metal pad. Directing aluminum metal from the molten metal pad of purification unit 212 to the electrolyte can include flowing the aluminum metal to the electrolyte and supplying an electrical current to the anode.

[0054] In some embodiments, purification unit 212 includes a molten metal mat, an electrolyte, and purified aluminum. In one embodiment, the electrolyte separates the molten metal mat from the purified aluminum. In one embodiment, the purified aluminum defines the top liquid layer of purification unit 21, the electrolyte defines the middle liquid layer of purification unit 212, and the molten metal mat defines the bottom liquid layer of purification unit 212. The density of the purified aluminum in purification unit 212 can be less than the density of the electrolyte in purification unit 212. The density of the electrolyte can be less than the density of the molten metal mat in purification unit 212. The electrolyte can separate the top layer of purified aluminum from the molten metal mat. In this regard, the composition of the electrolyte can be selected such that the electrolyte has a lower density than the molten metal mat and a higher density than the purified aluminum. In some embodiments, the electrolyte includes one or more molten salts. In some embodiments, the electrolyte includes at least one of a fluoride and / or a chloride. In some embodiments, the electrolyte includes at least one of a fluoride and / or a chloride of Na, K, Al, Ba, Ca, Ce, La, Cs, Rb, or a combination thereof. In some embodiments, the molten metal pad includes at least one alloy including one or more of Al, Si, Cu, Fe, Sb, Gd, Cd, Sn, Pb, and impurities.

[0055] In some embodiments, process 200 may include removing at least some of the purified aluminum from purification unit 212 to form purified aluminum stream 214. In some embodiments, purified aluminum may be removed substantially continuously via purified aluminum stream 214 during operation of purification unit 212. In some embodiments, removing purified aluminum from purification unit 212 includes periodically removing purified aluminum from purification unit 212 via purified aluminum stream 214. In some embodiments, removing purified aluminum from purification unit 212 via purified aluminum stream 214 includes removing purified aluminum from purification unit 212 at a first removal rate. The first removal rate may remain constant or may vary, including stopping and starting the removal of purified aluminum from purification unit 212. In some embodiments, the first removal rate may be controlled, for example, based at least in part on a second removal rate. In some embodiments, purified aluminum may be periodically removed via purified aluminum stream 214 during operation of purification unit 212. In some embodiments, the removal step is accomplished using equipment configured to remove purified aluminum product 250 without contaminating the product (e.g., with alumina, graphite, etc.).

[0056] In some embodiments, the purified aluminum stream 214 includes at least 95% by weight aluminum, such as any of the amounts of aluminum described herein.

[0057] As previously mentioned, the residue stream may include elements such as silicon and iron. In some embodiments, the residue stream 216 includes at least 0.5% by weight Si. In one embodiment, the residue stream includes at least 1% by weight Si. In another embodiment, the residue stream includes at least 2% by weight Si. In yet another embodiment, the residue stream includes at least 3% by weight Si. In another embodiment, the residue stream includes at least 5% by weight Si. In yet another embodiment, the residue stream includes at least 7% by weight Si. In another embodiment, the residue stream includes at least 10% by weight Si. In yet another embodiment, the residue stream includes at least 15% by weight Si. In another embodiment, the residue stream includes at least 20% by weight Si. In yet another embodiment, the residue stream includes at least 25% by weight Si. In another embodiment, the residue stream includes at least 30% by weight Si. In yet another embodiment, the residue stream includes at least 35% by weight Si. In another embodiment, the residue stream includes at least 40% by weight Si. In yet another embodiment, the residue stream includes at least 45% by weight Si. In another embodiment, the residue stream includes at least 50% by weight Si. In yet another embodiment, the residual stream comprises at least 55% by weight Si. In another embodiment, the residual stream comprises at least 60% by weight Si. In yet another embodiment, the residual stream comprises at least 65% by weight Si. In another embodiment, the residual stream comprises at least 70% by weight Si. In yet another embodiment, the residual stream comprises at least 75% by weight Si. In another embodiment, the residual stream comprises at least 80% by weight Si. In yet another embodiment, the residual stream comprises at least 85% by weight Si. In another embodiment, the residual stream comprises at least 90% by weight Si. In yet another embodiment, the residual stream comprises at least 95% by weight Si.

[0058] In some embodiments, the residue stream 216 comprises at least 0.5 wt% Fe. In one embodiment, the residue stream comprises at least 1 wt% Fe. In another embodiment, the residue stream comprises at least 2 wt% Fe. In yet another embodiment, the residue stream comprises at least 3 wt% Fe. In another embodiment, the residue stream comprises at least 5 wt% Fe. In yet another embodiment, the residue stream comprises at least 7 wt% Fe. In another embodiment, the residue stream comprises at least 10 wt% Fe. In yet another embodiment, the residue stream comprises at least 15 wt% Fe. In another embodiment, the residue stream comprises at least 20 wt% Fe. In yet another embodiment, the residue stream comprises at least 25 wt% Fe. In another embodiment, the residue stream comprises at least 30 wt% Fe. In yet another embodiment, the residue stream comprises at least 35 wt% Fe. In another embodiment, the residue stream comprises at least 40 wt% Fe. In yet another embodiment, the residue stream comprises at least 45 wt% Fe. In another embodiment, the residue stream comprises at least 50 wt% Fe. In yet another embodiment, the residue stream comprises at least 55 wt% Fe. In another embodiment, the residual stream comprises at least 60% by weight of Fe. In yet another embodiment, the residual stream comprises at least 65% by weight of Fe. In another embodiment, the residual stream comprises at least 70% by weight of Fe. In yet another embodiment, the residual stream comprises at least 75% by weight of Fe. In another embodiment, the residual stream comprises at least 80% by weight of Fe. In yet another embodiment, the residual stream comprises at least 85% by weight of Fe. In another embodiment, the residual stream comprises at least 90% by weight of Fe. In yet another embodiment, the residual stream comprises at least 95% by weight of Fe.

[0059] In some embodiments, the residual stream comprises both silicon and iron, and the residual stream comprises at least 1 weight percent silicon plus iron (i.e., ≥1 weight percent Si+Fe). In another embodiment, the residual stream comprises at least 2 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 3 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 5 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 7 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 10 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 15 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 20 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 25 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 30 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 35 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 40 weight percent (Si+Fe). In yet another embodiment, the residual stream comprises at least 45 weight percent (Si+Fe). In another embodiment, the residual stream comprises at least 50 wt % (Si + Fe). In yet another embodiment, the residual stream comprises at least 55 wt % (Si + Fe). In another embodiment, the residual stream comprises at least 60 wt % (Si + Fe). In yet another embodiment, the residual stream comprises at least 65 wt % (Si + Fe). In another embodiment, the residual stream comprises at least 70 wt % (Si + Fe). In yet another embodiment, the residual stream comprises at least 75 wt % (Si + Fe). In another embodiment, the residual stream comprises at least 80 wt % (Si + Fe). In yet another embodiment, the residual stream comprises at least 85 wt % (Si + Fe). In another embodiment, the residual stream comprises at least 90 wt % (Si + Fe). In yet another embodiment, the residual stream comprises at least 95 wt % (Si + Fe).

[0060] In some embodiments, the residual stream 216 comprises no more than 95% by weight Al (aluminum). In one embodiment, the residual stream 216 comprises no more than 90% by weight Al. In another embodiment, the residual stream 216 comprises no more than 85% by weight Al. In yet another embodiment, the residual stream 216 comprises no more than 80% by weight Al. In another embodiment, the residual stream 216 comprises no more than 75% by weight Al. In yet another embodiment, the residual stream 216 comprises no more than 70% by weight Al. In another embodiment, the residual stream 216 comprises no more than 65% by weight Al. In yet another embodiment, the residual stream 216 comprises no more than 60% by weight Al. In another embodiment, the residual stream 216 comprises no more than 55% by weight Al. In yet another embodiment, the residual stream 216 comprises no more than 50% by weight Al. In another embodiment, the residual stream 216 comprises no more than 45% by weight Al. In yet another embodiment, the residual stream 216 comprises no more than 40% by weight Al. In another embodiment, the residue stream 216 comprises no more than 35 wt% Al. In yet another embodiment, the residue stream 216 comprises no more than 30 wt% Al. In another embodiment, the residue stream 216 comprises no more than 25 wt% Al. In yet another embodiment, the residue stream 216 comprises no more than 20 wt% Al. In another embodiment, the residue stream 216 comprises no more than 15 wt% Al. In yet another embodiment, the residue stream 216 comprises no more than 10 wt% Al. In another embodiment, the residue stream 216 comprises no more than 5 wt% Al.

[0061] Process 200 can include the step of separating 218 the residue stream 216 into the residue 246, by-product stream or its combination of recovery. In some embodiments, the residue stream 216 is only separated into by-product streams (e.g., the first by-product stream 220, the second by-product stream 222 or the third by-product stream 224). In some embodiments, the residue stream 216 is not further separated, and the residue stream 216 is the residue 246 of recovery. In some embodiments, the residue 246 of recovery does not include the same component as the by-product stream. In some embodiments, the residue 246 of recovery includes the same component as at least one by-product stream. In some embodiments, the residue 246 of recovery is identical with all by-product streams.

[0062] Depending on the application, the amount of by-product stream exiting separation step 218 may vary. Figure 2As shown, the residue stream 216 can be separated into at least one by-product stream, for example, a first by-product stream 220, a second by-product stream 222, and a third by-product stream 224. In some embodiments, the residue stream 216 can be separated into two or more by-product streams, for example, only two by-product streams, or three or more by-product streams, or four or more by-product streams, or five or more by-product streams, or six or more by-product streams, or seven or more by-product streams, or eight or more by-product streams, or nine or more by-product streams, or ten or more by-product streams.

[0063] In some embodiments, by-product streams can be all identical or can all be different from each other in composition.In some embodiments, some by-product streams can be identical in composition, and some by-product streams can be different from each other.In some embodiments, two or more streams can be identical in composition (for example, the first by-product stream 220 and the second by-product stream 222) and can be different from other streams (for example, the 3rd by-product stream 224).The first by-product stream 220, the second by-product stream 222 and the 3rd by-product stream 224 can be identical to each other in composition or all be different from each other.

[0064] The byproduct streams of the disclosure (eg, in the illustrated embodiment, first byproduct stream 220, second byproduct stream 222, and / or third byproduct stream 224) can include at least one of silicon, manganese, iron, zinc, copper, and combinations thereof.

[0065] In some embodiments, at least one by-product stream comprises at least 1% by weight Si (silicon). In one embodiment, at least one by-product stream comprises at least 3% by weight Si. In another embodiment, at least one by-product stream comprises at least 5% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 7% by weight Si. In another embodiment, at least one by-product stream comprises at least 10% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 12% by weight Si. In another embodiment, at least one by-product stream comprises at least 15% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 20% by weight Si. In another embodiment, at least one by-product stream comprises at least 25% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 30% by weight Si. In another embodiment, at least one by-product stream comprises at least 35% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 40% by weight Si. In another embodiment, at least one by-product stream comprises at least 45% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 50% by weight Si. In another embodiment, at least one by-product stream comprises at least 55% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 60% by weight Si. In another embodiment, at least one by-product stream comprises at least 65% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 70% by weight Si. In another embodiment, at least one by-product stream comprises at least 75% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 80% by weight Si. In another embodiment, at least one by-product stream comprises at least 85% by weight Si. In yet another embodiment, at least one by-product stream comprises at least 90% by weight Si. In another embodiment, at least one by-product stream comprises at least 95% by weight Si.

[0066] In some embodiments, at least one by-product stream comprises at least 1 wt % Mn (manganese). In one embodiment, at least one by-product stream comprises at least 3 wt % Mn. In another embodiment, at least one by-product stream comprises at least 5 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 7 wt % Mn. In another embodiment, at least one by-product stream comprises at least 10 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 12 wt % Mn. In another embodiment, at least one by-product stream comprises at least 15 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 20 wt % Mn. In another embodiment, at least one by-product stream comprises at least 25 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 30 wt % Mn. In another embodiment, at least one by-product stream comprises at least 35 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 40 wt % Mn. In another embodiment, at least one by-product stream comprises at least 45 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 50 wt % Mn. In another embodiment, at least one by-product stream comprises at least 55 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 60 wt % Mn. In another embodiment, at least one by-product stream comprises at least 65 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 70 wt % Mn. In another embodiment, at least one by-product stream comprises at least 75 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 80 wt % Mn. In another embodiment, at least one by-product stream comprises at least 85 wt % Mn. In yet another embodiment, at least one by-product stream comprises at least 90 wt % Mn. In another embodiment, at least one by-product stream comprises at least 95 wt % Mn.

[0067] In some embodiments, at least one by-product stream comprises at least 1% by weight of Fe (iron). In one embodiment, at least one by-product stream comprises at least 3% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 5% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 7% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 10% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 12% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 15% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 20% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 25% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 30% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 35% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 40% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 45% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 50% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 55% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 60% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 65% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 70% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 75% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 80% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 85% by weight of Fe. In yet another embodiment, at least one by-product stream comprises at least 90% by weight of Fe. In another embodiment, at least one by-product stream comprises at least 95% by weight of Fe.

[0068] In some embodiments, at least one by-product stream comprises at least 1% by weight Zn (zinc). In one embodiment, at least one by-product stream comprises at least 3% by weight Zn. In another embodiment, at least one by-product stream comprises at least 5% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 7% by weight Zn. In another embodiment, at least one by-product stream comprises at least 10% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 12% by weight Zn. In another embodiment, at least one by-product stream comprises at least 15% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 20% by weight Zn. In another embodiment, at least one by-product stream comprises at least 25% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 30% by weight Zn. In another embodiment, at least one by-product stream comprises at least 35% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 40% by weight Zn. In another embodiment, at least one by-product stream comprises at least 45% by weight Zn. In yet another embodiment, at least one by-product stream comprises at least 50% by weight of Zn. In another embodiment, at least one by-product stream comprises at least 55% by weight of Zn. In yet another embodiment, at least one by-product stream comprises at least 60% by weight of Zn. In another embodiment, at least one by-product stream comprises at least 65% by weight of Zn. In yet another embodiment, at least one by-product stream comprises at least 70% by weight of Zn. In another embodiment, at least one by-product stream comprises at least 75% by weight of Zn. In yet another embodiment, at least one by-product stream comprises at least 80% by weight of Zn. In another embodiment, at least one by-product stream comprises at least 85% by weight of Zn. In yet another embodiment, at least one by-product stream comprises at least 90% by weight of Zn. In another embodiment, at least one by-product stream comprises at least 95% by weight of Zn.

[0069] In some embodiments, at least one by-product stream comprises at least 1% by weight of Cu (copper). In one embodiment, at least one by-product stream comprises at least 3% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 5% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 7% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 10% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 12% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 15% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 20% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 25% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 30% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 35% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 40% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 45% by weight of Cu. In yet another embodiment, at least one by-product stream comprises at least 50% by weight of Cu. In another embodiment, at least one by-product stream comprises at least 55 wt % Cu. In yet another embodiment, at least one by-product stream comprises at least 60 wt % Cu. In another embodiment, at least one by-product stream comprises at least 65 wt % Cu. In yet another embodiment, at least one by-product stream comprises at least 70 wt % Cu. In another embodiment, at least one by-product stream comprises at least 75 wt % Cu. In yet another embodiment, at least one by-product stream comprises at least 80 wt % Cu. In another embodiment, at least one by-product stream comprises at least 85 wt % Cu. In yet another embodiment, at least one by-product stream comprises at least 90 wt % Cu. In another embodiment, at least one by-product stream comprises at least 95 wt % Cu.

[0070] In some embodiments, first byproduct stream 220, second byproduct stream 222, third byproduct stream 224, or any combination thereof can include at least one of the following: at least 12 wt% Si, at least 3 wt% Mn, at least 3 wt% Fe, and combinations thereof, such as any of the amounts recited above. In some embodiments, first byproduct stream 220, second byproduct stream 222, and / or third byproduct stream 224 can include at least 5% of at least one of the following: Si, Mn, Fe, Zn, Cu, and combinations thereof, such as any of the amounts recited above.

[0071] As previously described, additional components 238 may be used in process 200. In one embodiment, additional component 238 may include at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof. In one embodiment, the additional component may include an aluminum scrap alloy, as described herein. Additional component 238 may be added to any stream described herein (e.g., purified aluminum stream 214, purified aluminum product 250, first byproduct stream 220, second byproduct stream 222, and / or third byproduct stream 224). Additional component 238 may be selected in an amount suitable for achieving a predetermined aluminum alloy product composition.

[0072] In some embodiments, one or more streams of the disclosure are mixed with additional component 238 and / or additional component 244. In some embodiments, additional component 238 and / or additional component 244 are not added to the streams. The steps of mixing the byproduct streams (e.g., first byproduct stream 220 and second byproduct stream 222) with the purified aluminum stream 214 (e.g., mixing step 230 and / or mixing step 234) may include adding additional component 238. Figure 2 In the embodiment shown, the mixing step 234 includes adding an additional component 238. In some embodiments, the additional component 238 can be added to the third byproduct stream 224 and / or the purified aluminum product 250.

[0073] The process 200 may include the step of mixing 230 at least a portion 220 of the first byproduct stream with at least a portion of the purified aluminum from the purified aluminum stream 214 to produce an aluminum alloy product (ie, a first predetermined aluminum alloy product 232 ).

[0074] The process 200 may include the step of mixing 234 at least a portion of the second byproduct stream 222 with at least a portion of the purified aluminum from the purified aluminum stream 214 to produce an aluminum alloy product, i.e., a second predetermined aluminum alloy product 236. The second predetermined aluminum alloy product may have a different composition than the first predetermined aluminum alloy product.

[0075] The first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can have a composition consistent with any of the 1xxx-8xxx aluminum alloy products, such as any of the 1xxx-8xxx aluminum alloys described in the Aluminum Association document, "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys." The first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can have a composition consistent with any of the 1xx-8xx aluminum alloy products, such as any of the 1xx-8xx aluminum alloys described in the Aluminum Association document, "Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingots." The first and / or second predetermined aluminum alloy products can be in any suitable form, such as in the form of an ingot, billet, powder, wire, strip, etc. Suitable wrought products (foils, sheets, plates, forgings, extrusions), shaped cast products (e.g., die cast products), and additively manufactured products (e.g., 3D printed products) may be produced from the first and / or second predetermined aluminum alloy products.

[0076] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can have a composition consistent with a 1xxx or 1xx aluminum alloy. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can be at least 99.5% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can be at least 99.6% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 can be at least 99.7% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may be at least 99.75% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may be at least 99.8% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may be at least 99.85% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may be at least 99.9% by weight and up to 99.999% by weight aluminum. In some embodiments, the aluminum purity of the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may be at least 99.95 wt. % up to 99.999 wt. % aluminum.

[0077] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 2xxx aluminum alloy.

[0078] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 3xxx aluminum alloy.

[0079] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 4xxx aluminum alloy.

[0080] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 5xxx aluminum alloy.

[0081] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 6xxx aluminum alloy.

[0082] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 7xxx aluminum alloy.

[0083] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with an 8xxx aluminum alloy.

[0084] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 2xx aluminum alloy.

[0085] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 3xx aluminum alloy.

[0086] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 4xx aluminum alloy.

[0087] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 5xx aluminum alloy.

[0088] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with a 7xx aluminum alloy.

[0089] In some embodiments, the first predetermined aluminum alloy product 232 and / or the second predetermined aluminum alloy product 236 may have a composition consistent with an 8xx aluminum alloy.

[0090] While the methods described herein generally relate to purifying aluminum and aluminum purification units, the devices, systems, and methods described herein are applicable to purifying other materials (e.g., magnesium) or to different types of units, such as different purification units (e.g., magnesium purification units). In some embodiments, the purification unit includes at least one electrode, such as a cathode or an anode.

[0091] While several embodiments of the disclosure have been described, it should be understood that these embodiments are merely illustrative and non-restrictive, and that numerous modifications may become apparent to one of ordinary skill in the art. The various steps may be performed in any desired order (and any desired steps may be added and / or any desired steps may be eliminated). For example, a predetermined aluminum alloy product may be produced by mixing any of the streams described herein (e.g., precursor 242 with purified aluminum stream 214). The exemplary embodiments of purified aluminum are not intended to be exhaustive. The features and characteristics of the disclosure may be combined in any manner.

[0092] In addition, the disclosure is explained with reference to the accompanying drawings, in which similar structures are referred to by similar reference numerals in several views. The accompanying drawings constitute a part of this specification and include illustrative embodiments of the disclosure and illustrate various objects and features of the disclosure. In addition, the drawings are not necessarily drawn to scale, and some features may be exaggerated to show details of specific components. In addition, any measurements, specifications, etc. shown in the drawings are intended to be illustrative and not restrictive. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to use the disclosure in various ways.

[0093] In addition to the benefits and improvements already disclosed, other objects and advantages of the disclosure will become apparent from the following description taken in conjunction with the accompanying drawings. Detailed embodiments of the disclosure are disclosed herein; however, it should be understood that the disclosed embodiments are merely illustrative of the disclosure that can be implemented in various forms. Additionally, each example provided in conjunction with various embodiments of the present invention is intended to be illustrative and not restrictive.

[0094] Throughout the specification and claims, the following terms take the meanings explicitly associated with this document unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment" and "in some embodiments" do not necessarily refer to the same embodiment, although they may refer to the same embodiment. In addition, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to different embodiments, although they may refer to different embodiments. Therefore, as described below, various embodiments of the present invention can be easily combined without departing from the scope or spirit of the present invention.

[0095] Additionally, as used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or," unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. Additionally, throughout this specification, the meanings of "a," "an," and "the" include plural references. The meaning of "in" includes "among" and "on."

Claims

1. A method comprising: (a) adding a feedstock to an aluminum purification unit, wherein the feedstock comprises aluminum scrap; (b) purifying the feedstock, thereby producing a purified aluminum stream and a residue stream; (c) separating components of the residue stream, thereby producing at least a first by-product stream and a second by-product stream; as well as (d) combining at least a portion of the first byproduct stream with at least a portion of the purified aluminum from the purified aluminum stream to produce an aluminum alloy product.

2. The method of claim 1 , wherein the feedstock comprises at least 50 wt% Al, or at least 55 wt% Al, or at least 60 wt% Al, or at least 65 wt% Al, or at least 70 wt% Al, or at least 75 wt% Al, or at least 80 wt% Al, or at least 85 wt% Al, or at least 90 wt% Al, or at least 95 wt% Al, or at least 99 wt% Al, or at least 99.5 wt% Al.

3. The method according to any one of the preceding claims, wherein the aluminum scrap comprises at least 5 wt% Al of the feedstock, or at least 10 wt% Al of the feedstock, or at least 15 wt% Al of the feedstock, or at least 20 wt% Al of the feedstock, or at least 25 wt% Al of the feedstock, or at least 30 wt% Al of the feedstock, or at least 35 wt% Al of the feedstock, or at least 40 wt% Al of the feedstock, or at least 45 wt% Al of the feedstock, or at least 50 wt% Al of the feedstock, or % Al of the raw material, or at least 55 wt % Al of the raw material, or at least 60 wt % Al of the raw material, or at least 65 wt % Al of the raw material, or at least 70 wt % Al of the raw material, or at least 75 wt % Al of the raw material, or at least 80 wt % Al of the raw material, or at least 85 wt % Al of the raw material, or at least 90 wt % Al of the raw material, or at least 95 wt % Al of the raw material, or at least 99 wt % Al of the raw material, or at least 99.5 wt % Al of the raw material, or at least 100 wt % Al of the raw material.

4. A method according to any one of the preceding claims, wherein the purification step (b) comprises passing an electric current through at least one anode, through an electrolyte and into at least one cathode.

5. The method of any one of the preceding claims, wherein the purified aluminum stream comprises at least 95 wt% Al.

6. The method of any one of the preceding claims, wherein the purified aluminum stream comprises at least 99.5 wt.% Al.

7. The process according to any one of the preceding claims, wherein the residue stream comprises not more than 50 wt% Al.

8. A process according to any one of the preceding claims, wherein the residue stream comprises at least 3 wt% silicon.

9. A process according to any one of the preceding claims, wherein the residue stream comprises at least 3 wt% iron.

10. The method of any one of the preceding claims, wherein the aluminum alloy product comprises one of a 1xxx to 8xxx aluminum alloy composition or one of a 1xx to 8xx aluminum alloy composition.

11. The method according to any one of the preceding claims, further comprising: Additional components are mixed with the purified aluminum stream.

12. The method of claim 11, wherein the additional component comprises at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof.

13. The method of claim 11, wherein the additional component comprises at least one aluminum scrap alloy, wherein the aluminum scrap alloy is a scrap aluminum alloy.

14. The method according to any one of the preceding claims, further comprising: At least one of the first byproduct stream and / or the second byproduct stream is added to a precursor stream to produce the feedstock.

15. The method according to any one of the preceding claims, further comprising: Predetermined metals are added to a precursor stream to produce the feedstock.

16. The method of claim 15, wherein the predetermined metal is at least one of Si, Fe, Cu, Ce, Cs, Mg, Mn, Cr, Ni, Zn, Ti, Co, Sn, Sr, Li, V, Zr, Sc, and combinations thereof.

17. The method of claim 15, wherein the predetermined metal is at least one of Cu, Ce, Cs, Sn, Zn, or any combination thereof. The method of claim 15 , wherein the predetermined metal comprises Cu.

19. The process of any one of the preceding claims, wherein the first byproduct stream and / or the second byproduct stream comprises at least one of: at least 12 wt% Si, at least 3 wt% Mn, at least 3 wt% Fe, and combinations thereof.

20. The process of any one of the preceding claims, wherein the first byproduct stream and / or the second byproduct stream comprises at least 5% of at least one of: Si, Mn, Fe, Zn, Cu, and combinations thereof.

21. The method of any one of the preceding claims, wherein the feedstock comprises no more than 5 wt% alumina (Al2O3).

22. The method of any one of the preceding claims, wherein the aluminum alloy product comprises one of an ingot, billet, powder, wire, and strip.

23. The method of any one of the preceding claims, wherein the aluminum purification unit comprises a molten metal pad, a purified aluminum layer, and an electrolyte disposed between the molten metal pad and the purified aluminum layer.

24. The method of claim 23, wherein the density of the purified aluminum layer is less than the density of the electrolyte.

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