Aluminum alloys with low carbon footprint

Abstract

New methods of producing wrought aluminum alloys are described. The new methods may include, for instance, casting an aluminum alloy ingot or billet by mixing recycled aluminum alloy material with low CO2 primary aluminum, wherein, due to the mixing a 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx or 8xxx aluminum alloy composition is realized. The methods may further include producing a wrought aluminum alloy from the aluminum alloy ingot or billet. Accordingly, aluminum alloys may be produced with low greenhouse gas impact.

Description

Attorney Ref. No.: 176971.119484 / WO ALUMINUM ALLOYS WITH LOW CARBON FOOTPRINT CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 556,545, filed on February 22, 2024, entitled “ALUMINUM ALLOYS WITH LOW CARBON FOOTPRINT,” which application is incorporated herein by reference in its entirety. BACKGROUND

[0002] Carbon dioxide is a gas that can trap heat in the atmosphere, i.e., is considered a greenhouse gas. Carbon dioxide may enter the atmosphere through burning fossil fuels and also as a result of certain chemical reactions (e.g., cement production). There is an on-going effort to reduce carbon dioxide and other greenhouse gas emissions. SUMMARY OF THE DISCLOSURE

[0003] Broadly, the present application relates to new methods of producing aluminum alloys with low greenhouse gas impact. In one embodiment, and referring now to FIG. 1, a method (10) may include casting (100) an aluminum alloy ingot or billet, wherein the casting step (100) comprises mixing recycled aluminum alloy material with low CO2 primary aluminum. Due to the mixing of the recycled aluminum alloy material with the low CO2 primary aluminum, a 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx or 8xxx aluminum alloy composition is realized. The method (10) further includes producing (200) a wrought aluminum alloy product from the aluminum alloy ingot or billet. Due to the combined use of recycled aluminum alloy material and low CO2 primary aluminum, the resulting wrought aluminum alloy product has a low greenhouse gas impact.

[0004] As noted above, the casting step (100) generally comprises mixing one or more recycled aluminum alloy materials with low CO2 primary aluminum to achieve one of a 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx or 8xxx aluminum alloy composition. The 2xxx-8xxx aluminum alloy compositions are known to those skilled in the art and are defined in ANSI H35.1 (2009). The recycled aluminum alloy material generally includes aluminum alloys produced from aluminum alloy scrap. The aluminum alloy scrap may be from any suitable source, such as, for instance, aluminum alloys used in cans (e.g., beverage cans), building and construction products (e.g., siding, gutters), transportation (e.g., aerospace, automotive, motorcycles, bicycles), electrical applications (e.g., wires / wiring, rods), consumer products (e.g., tread sheet, cookware), and machinery and equipment, among others. Once the scrap is properly processedAttorney Ref. No.: 176971.119484 / WO to remove any residual materials, such as paints, plastics, and non-aluminum materials (if applicable), the recycled aluminum alloy material is realized and may be used in the casting step (100). In one embodiment, a chemical analysis of the recycled aluminum alloy material is completed to determine its composition. In one embodiment, the recycled aluminum alloy material is prepared remotely, solidified and then shipped to a casting location for completion of the casting step (100).

[0005] To achieve the desired composition, the casting step (100) generally involves mixing the recycled aluminum alloy material with low CO2 primary aluminum. As used herein, “low CO2 primary aluminum” is primary aluminum that is certified to have been produced with carbon emissions of not greater than four CO2e per ton of primary aluminum produced. As used herein, CO2e means “carbon dioxide equivalents,” which may be readily calculated by primary aluminum producers using known standards. In one embodiment, the low CO2 primary aluminum is certified to have been produced with carbon emissions of not greater than three CO2e per ton of primary aluminum produced. In another embodiment, the low CO2 primary aluminum is certified to have been produced with not greater than two CO2e per ton of primary aluminum produced. In yet another embodiment, the low CO2 primary aluminum is certified to have been produced with carbon emissions of not greater than two CO2e per ton of primary aluminum produced. In another embodiment, the low CO2 primary aluminum is certified to have been produced with not greater than one CO2e per ton of primary aluminum produced. In yet another embodiment, the low CO2 primary aluminum is certified to have been produced with carbon emissions of not greater than 0.5 CO2e per ton of primary aluminum produced. In another embodiment, the low CO2 primary aluminum is certified to have been produced with zero CO2e per ton of primary aluminum produced. In one embodiment, the low CO2 aluminum is obtained from an aluminum smelter, wherein the aluminum smelter uses one or more aluminum electrolysis cells to produce the low CO2 primary aluminum. Low CO2 primary aluminum may be obtained from, for instance, ELYSIS, 1 Place Ville Marie, Suite 2323, Montreal (Quebec) Canada H3B 3M5. In one embodiment, ultra-low CO2 primary aluminum is used, i.e., primary aluminum certified to have been produced with carbon emissions of not greater than two CO2e per ton of primary aluminum produced.

[0006] In some embodiments, conventional primary aluminum may be used in addition to the low CO2 primary aluminum to facilitate production of the ingot or billet of the casting step. However, conventional primary aluminum may realize high CO2 emissions (e.g., at least 8Attorney Ref. No.: 176971.119484 / WO CO2e per ton of primary aluminum produced). Thus, its use is not preferred and may be omitted. Conventional primary aluminum is primary aluminum produced by traditional aluminum smelting methods, such as the Hall-Heroult process. Conventional grades of primary aluminum include P1020 and P0610, among others.

[0007] In one embodiment, the casting step (100) comprising using not greater than 20 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 18 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 16 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 14 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 12 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 10 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 9 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 8 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 7 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 6 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 5 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 4 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 3 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using not greater than 2 wt. % of conventional primary aluminum. In yet another embodiment, the casting step (100) comprising using not greater than 1 wt. % of conventional primary aluminum. In another embodiment, the casting step (100) comprising using no (zero) conventional primary aluminum.

[0008] With continued reference to FIG.1, the method (10) may optionally include adding alloying ingredients (150) during the casting step to achieve the desired composition. For instance, one or more of silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), silver (Ag), lithium (Li), vanadium (V), and / or zirconium (Zr), may be added during casting to achieve the desired aluminum alloy composition. Grain refiners (e.g., TiB2; TiC) and / or other casting agents (e.g., calcium, strontium) may also be added.Attorney Ref. No.: 176971.119484 / WO

[0009] After casting, the ingot or billet may be processed (200) to produce a wrought aluminum alloy product. The wrought aluminum alloy product may be any of a sheet, plate, forging or extrusion. In one approach, the wrought aluminum alloy is a precipitation hardened (heat treatable) aluminum alloy. In one embodiment, the precipitation hardened aluminum alloy is one of a 2xxx, 6xxx, or 7xxx aluminum alloy. In another approach, the wrought aluminum alloy is a non-heat treatable aluminum alloy. In one embodiment, the non-heat treatable aluminum alloy is a 3xxx, 4xxx, or 5xxx aluminum alloy. The wrought aluminum alloy product may be used in any suitable end use application. In one embodiment, the wrought aluminum alloy product is in the form of a sheet. In one embodiment, the sheet is an automotive sheet product.

[0010] In another approach (not illustrated), a method includes producing a shape cast product by mixing recycled aluminum alloy material with low CO2 primary aluminum, optionally with alloying ingredients, such as one or more of one or more of silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), silver (Ag), lithium (Li), vanadium (V), and / or zirconium (Zr), grain refiners (e.g., TiB2; TiC) and / or casting agents (e.g., calcium, strontium) to achieve the desired composition for the shape cast product followed by shape casting of the mixture. Due to the mixing of the recycled aluminum alloy material with the low CO2 primary aluminum and the optional alloying ingredients, a 1xx, 2xx, 3xx, 4xx, 5xx, 7xx or 8xx aluminum casting alloy composition may be realized (e.g., as per the Aluminum Association document “Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingots,” i.e., the Pink ink Sheets”). Accordingly, shape cast products with low greenhouse gas impact may be produced. The shape cast products may be produced from any known or developed shape casting technique, such as permanent or semi-permanent mold casting, squeeze casting, high or low pressure die casting, pressure or gravity casting, lost foam casting, investment casting, V-mold casting, sand mold casting and the like. Shape cast products are distinguished from ingot or billet in that shape cast products generally have intricate geometrical features and shape cast products are generally not further worked after casting because they are in substantially final form. i. Miscellaneous

[0011] These and other aspects, advantages, and novel features of this new technology are set forth in part in the description that follows and will become apparent to those skilled in theAttorney Ref. No.: 176971.119484 / WO art upon examination of the following description and figures, or may be learned by practicing one or more embodiments of the technology provided for by the present disclosure.

[0012] Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.

[0013] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases “in one embodiment” and “in some embodiments” as used herein do not necessarily refer to the same embodiment(s), though they may. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although they may. Thus, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0014] In addition, 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. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references, unless the context clearly dictates otherwise. The meaning of “in” includes “in” and “on”, unless the context clearly dictates otherwise.

[0015] While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. Further still, unless the context clearly requires otherwise, the various steps may be carried out in any desired order, and any applicable steps may be added and / or eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG.1 is a flow diagram illustrating one embodiment of a method for producing an aluminum alloy product in accordance with the present disclosure. DETAILED DESCRIPTION

[0017] Example 1 – Production of 6xxx aluminum alloy (prophetic)Attorney Ref. No.: 176971.119484 / WO

[0018] Aluminum alloy beverage can scrap is obtained and processed to realize a recycled aluminum alloy material. Because the recycled aluminum alloy material is derived from beverage can scrap, it may contain silicon and magnesium. The recycled aluminum alloy material is then melted and mixed with low CO2 primary aluminum to achieve a 6xxx aluminum alloy composition (e.g., an aluminum alloy having 0.4-1.5 wt. % Si and 0.4-1.5 wt. % Mg, wherein an amount of silicon and magnesium is sufficient to produce magnesium silicide precipitates prior to or upon aging of the aluminum alloy). The melt is then solidified into an ingot, after which the ingot is wrought processed to yield a 6xxx aluminum alloy sheet product suited for automotive applications.

[0019] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present disclosure.

Claims

Attorney Ref. No.: 176971.119484 / WO CLAIMS What is claimed is:

1. A method comprising: (a) casting an aluminum alloy ingot or billet, wherein the casting comprises: (i) mixing recycled aluminum alloy material with low CO2 primary aluminum, wherein, due to the mixing a 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx or 8xxx aluminum alloy composition is realized; (ii) wherein the recycled aluminum alloy material is derived from aluminum alloy scrap; and (iii) wherein the low CO2 primary aluminum is certified to have been produced with carbon emissions of not greater than four CO2e per ton of primary aluminum produced; and (b) producing a wrought aluminum alloy from the aluminum alloy ingot or billet.

2. The method of claim 1, wherein the low CO2 primary aluminum is certified to have been produced with carbon emissions of not greater than three CO2e per ton of primary aluminum produced, or not greater than two CO2e per ton of primary aluminum produced, or not greater than one CO2e per ton of primary aluminum produced, or not greater than 0.5 CO2e per ton of primary aluminum produced, or zero CO2e per ton of primary aluminum produced.

3. The method of claim any of the preceding claims, wherein the casting step (a) comprising using not greater than 20 wt. % of conventional primary aluminum, or not greater than 18 wt. % of conventional primary aluminum, or not greater than 16 wt. % of conventional primary aluminum, or not greater than 14 wt. % of conventional primary aluminum, or not greater than 12 wt. % of conventional primary aluminum, or not greater than 10 wt. % of conventional primary aluminum, or not greater than 9 wt. % of conventional primary aluminum, or not greater than 8 wt. % of conventional primary aluminum, or not greater than, 7 wt. % of conventional primary aluminum, or not greater than 6 wt. % of conventional primary aluminum, or not greater than 5 wt. % of conventional primary aluminum, or not greater than 4 wt. % of conventional primary aluminum, or not greater than 3 wt. % of conventional primary aluminum, or not greater than 2 wt. % of conventional primary aluminum, or not greater than 1 wt. % of conventional primary aluminum.

4. The method of any of claims 1-2, wherein the casting step (a) comprising using no conventional primary aluminum.Attorney Ref. No.: 176971.119484 / WO 5. The method of any of the preceding claims, wherein the wrought aluminum alloy is a sheet, plate, forging or extrusion.

6. The method of any of the preceding claims, wherein the wrought aluminum alloy is a precipitation hardened aluminum alloy.

7. The method of claim 6, wherein the precipitation hardened aluminum alloy is one of a 2xxx, 6xxx, or 7xxx aluminum alloy.

8. The method of any of claims 1-5, wherein the wrought aluminum alloy is a non-heat treatable aluminum alloy.

9. The method of claim 9, wherein the non-heat treatable aluminum alloy is a 3xxx, 4xxx, or 5xxx aluminum alloy.

10. The method of any of the preceding claims, wherein the wrought aluminum alloy is in the form of a sheet.

11. The method of any of claim 10, wherein the sheet is an automotive sheet product.