Aluminium recycling

Last updated
An aluminium recycling symbol. Recycling-Code-41.svg
An aluminium recycling symbol.
The European Committee for Standardization logo for aluminium recycling. CEN recycling aluminium.svg
The European Committee for Standardization logo for aluminium recycling.

Aluminium recycling is the process in which secondary commercial aluminium is created from scrap or other forms of end-of-life or otherwise unusable aluminium. [1] It involves re-melting the metal, which is cheaper and more energy-efficient than the production of virgin aluminium by electrolysis of alumina (Al2O3) refined from raw bauxite by use of the Bayer and Hall–Héroult processes.

Contents

Recycling scrap aluminium requires only 5% of the energy used to make new aluminium from the raw ore. [2] In 2022, the United States produced 3.86 metric tons of secondary aluminium for every metric ton of primary aluminium produced. Over the same time period, secondary aluminium accounted for 34% of the total new supply of aluminium including imports. [3] Used beverage containers are the largest component of processed aluminium scrap, and most of it is manufactured back into aluminium cans. [4]

Recycling process

Collection & sorting

The first step in aluminium recycling is the collection and sorting of aluminium scrap from various sources. [5] Scrap aluminium comes primarily from either manufacturing scrap or end-of-life aluminium products such as vehicles, building materials, and consumer products. [5] Manufacturing scrap includes shreds, shavings, cuttings, and other leftover aluminium from manufacturing processes. Post-consumer scrap consists of obsolete or discarded aluminium products. Aluminium cans, [6] in particular, are a major source of recyclable aluminium scrap. Once collected, aluminium scrap is sorted based on alloy type, grade, impurity levels, and other factors. [6] Sorting may be done manually or using technologies like eddy current separators, air classifiers, and density separators. [7] The scrap is sorted into categories like wrought alloy scrap, casting alloy scrap, used beverage cans, automobile scrap, and mixed scrap. Proper sorting is essential for producing high-quality recycled aluminium.

Pre-treatment

After sorting, the scrap may undergo pre-treatment processes to prepare it for melting. [8] These can include baling, shredding, crushing, granulating, decoating, and demagnetizing. [9] Shredding and crushing reduce the particle size of the scrap and liberate it from other materials, while granulating produces fine particles ideal for melting. [10] Thermal decoating removes coatings like paint and plastic from aluminium surfaces. [7] Demagnetizing removes iron particles clinging to the aluminium scrap. Pre-treatment improves the density of the scrap charge and removes contaminants, resulting in faster melting, cleaner metal, reduced dross formation, and lower energy consumption. [11]

Melting

Once pre-treated, the aluminium scrap undergoes melting and liquid metal treatment to produce refined aluminium alloy suitable for casting or reprocessing. [11] Different furnace types are used based on the type of scrap, desired metal quality, and economics. Smaller scrap is typically processed in rotary or reverberatory gas-fired furnaces, while large individual pieces of scrap can be charged directly into reverb furnaces through side wells. [10] Electric induction furnaces are also used. As the scrap melts, fluxes are added to bind and absorb impurities which are scraped off the top as dross. Chlorine gas may also be injected to remove impurities through flotation. The melt can then undergo refining processes like flux injection to further reduce hydrogen and impurities. Degassing removes dissolved hydrogen while chemical filtration removes solid impurities and inclusions. The final result is molten aluminium alloy ready for casting. [12]

Casting

The molten recycled aluminium is cast into solid forms such as ingots, sows, or directly into sheets or extrusion billets. Direct-chill casting is commonly used to solidify the liquid aluminium into large cylindrical billets for extrusion or rolling. [7] The direct chill method sprays water onto the hot metal as it exits the mold, quickly chilling it into a solid billet form. [13] For ingots, book molds are often used, producing slabbed ingots suitable for remelting or rolling. [14] Continuous casting directly shapes the aluminium into rolling slabs without an intermediate ingot casting step. Twin-belt or twin-roll strip casting produces alloy strips 6-7mm thick directly from the melt for subsequent rolling. The casting method depends on the subsequent processing and use of the recycled aluminium alloy. [15]

History

Model promoting aluminium recycling at Douglas Aircraft Company in 1942 Salvage demo.jpg
Model promoting aluminium recycling at Douglas Aircraft Company in 1942

Although aluminium in its pure form has been produced as early as 1825, [16] secondary aluminium production, or recycling, rose in volume with the introduction of industrially viable primary aluminium processes, namely the combination of the Bayer and Hall-Héroult processes. The Hall-Héroult process for aluminium production from alumina was invented in 1886 by Charles Hall and Paul Héroult. [17] Carl Josef Bayer created a multi-step process to convert raw Bauxite into alumina in 1888. [18] As aluminium production rose with the use of these two processes, aluminium recycling grew too. In 1904, the first two aluminium can recycling plants were built in the United States; one recycling plant was built in Chicago, Illinois and the other was built in Cleveland, Ohio. [19] Aluminium recycling increased most significantly in volume when metal resources were strained during WWI, as the U.S. government campaigned for civilians to donate old products such as aluminium pots, pans, boats, vehicles, and toys to recycle for the construction of aluminium airframes. [19]

Advantages

Aluminium is an infinitely recyclable material, and it takes up to 95 percent less energy to recycle it than to produce primary aluminium, which also limits emissions, including greenhouse gases. Today, about 75 percent of all aluminium produced in history, nearly a billion tons, is still in use. [20]

Press for aluminium cans.jpg
Compressed aluminium cans.jpg
Hydraulic press and baled cans prepared for transport

The recycling of aluminium generally produces significant cost savings over the production of new aluminium, even when the cost of collection, separation and recycling are taken into account. [21] Over the long term, even larger national savings are made when the reduction in the capital costs associated with landfills, mines, and international shipping of raw aluminium are considered.

Energy savings

Recycling aluminium uses about 5% of the energy required to create aluminium from bauxite; [22] the amount of energy required to convert aluminium oxide into aluminium can be vividly seen when the process is reversed during the combustion of thermite or ammonium perchlorate composite propellant.

Aluminium die extrusion is a specific way of getting reusable material from aluminium scraps but does not require a large energy output of a melting process. In 2003, half of the products manufactured with aluminium were sourced from recycled aluminium material. [23]

Environmental savings

The benefit with respect to emissions of carbon dioxide depends in part on the type of energy used. Electrolysis can be done using electricity from non-fossil-fuel sources, such as nuclear, geothermal, hydroelectric, or solar. Aluminium production is attracted to sources of cheap electricity. Canada, Brazil, Norway, and Venezuela have 61 to 99% hydroelectric power and are major aluminium producers. However the anodes widely used in the Hall–Héroult process are made of carbon and are consumed during aluminium production, generating large quantities of carbon dioxide, regardless of electricity source. [24] Efforts are underway to eliminate the need for carbon anodes. [25] The use of recycled aluminium also decreases the need for mining and refining bauxite.

The vast amount of aluminium used means that even small percentage losses are large expenses, so the flow of material is well monitored and accounted for financial reasons. Efficient production and recycling benefits the environment as well. [26]

Impact

Environmental

Because many countries continue to rely on coal-generated electricity for aluminium production, the aluminium industry contributes to 2% of global greenhouse gas emissions, around 1.1 billion tons of carbon dioxide. [27] Many countries now seek to decarbonize aluminium not only as it is the second most used metal in the world, but also because it would heavily address the total greenhouse gas emissions in an effort to slow climate change. [28]

As one of the most recyclable –and recycled– materials in use today, aluminium can be virtually infinitely recycled. Since recycled aluminium takes 5% of the energy used to make new aluminium, around 75% of aluminium manufactured continues to be in use today. [29] According to the Aluminium Association, in industrial markets such as automotive and building, aluminium is recycled at rates of up to 90%.

Since 1991, greenhouse gas emissions from aluminium cans have dropped about 40%, similar to energy demand levels. This can be attributed to a reduction in the carbon intensity of primary aluminium production, improving the efficacy of manufacturing operations, and lighter cans. [30] While primary aluminium only accounts for 26.6% of the can, it makes up the major source of the can's carbon footprint. For example, as of 2020, 86% of China's aluminium production relies mostly on coal-generated electricity. On the other hand, Canada sources roughly 90% of its primary aluminium production using hydroelectric power, considering it to be the most sustainable in the world. [28]

Aluminium and its applications are wide and numerous–from defense construction and electrical transmission to playing a key role in emission-reducing goods (electric vehicles and solar panels). As such, countries have begun to decarbonize aluminium to combat global climate change.

Economic

Aluminium recycling has several economic benefits when done properly. In fact, the Environmental Protection Agency considers recycling a "critical" part of the United States economy, contributing to tax revenue, wages, and job creation. [31] By facilitating scrap handling and improving its efficiency – from "end of life" scrap to repurposing scrap throughout the production stage ("in-house" scrap) – aluminium recycling helps in achieving the goals of a circular economy. [32] This type of economy focuses on minimizing the extraction of natural resources, leading to a reduction of consumer and industrial waste. A few examples of countries that have adopted the shift to a circular economy include the European Union, Finland, France, Slovenia, Italy, Germany, and the Netherlands. [33]

A recent study conducted within the United States has highlighted some ways that aluminium recycling has proven to have economic benefits, including:

As countries take note of the various economic and environmental benefits of aluminium recycling, increased efforts are expected to improve the efficacy of this process.

Recycling rates

According to 2020 data from the International Aluminium Institute, the global recycling efficiency rate is 76%. Around 75% of the almost 1.5 billion tonnes of aluminium ever produced is still in productive use today. [34]

Brazil recycles 98.2% of its aluminium can production, equivalent to 14.7 billion beverage cans per year, [35] ranking first in the world, more than Japan's 82.5% recovery rate. Brazil has topped the aluminium can recycling charts eight years in a row. [36]

Europe

Recycling rate for aluminium beverage cans
Country2021 [37]
Flag of Austria.svg  Austria 71%
Flag of Belgium (civil).svg  Belgium 94%
Flag of Bulgaria.svg  Bulgaria 83%
Flag of Croatia.svg  Croatia 80%
Flag of Cyprus.svg  Cyprus 28%
Flag of the Czech Republic.svg  Czech Republic 51%
Flag of Denmark.svg  Denmark 84%
Flag of Estonia.svg  Estonia 89%
Flag of Finland.svg  Finland 97%
Flag of France.svg  France 48%
Flag of Germany.svg  Germany 99%
Flag of Greece.svg  Greece 60%
Flag of Hungary.svg  Hungary 42%
Flag of Iceland.svg  Iceland 91%
Flag of Ireland.svg  Ireland 62%
Flag of Italy.svg  Italy 90%
Flag of Latvia.svg  Latvia 49%
Flag of Lithuania.svg  Lithuania 87%
Flag of Luxembourg.svg  Luxembourg 82%
Flag of Malta.svg  Malta 50%
Flag of the Netherlands.svg  Netherlands 82%
Flag of Norway.svg  Norway 92%
Flag of Poland.svg  Poland 79%
Flag of Portugal.svg  Portugal 36%
Flag of Romania.svg  Romania 35%
Flag of Slovakia.svg  Slovakia 58%
Flag of Slovenia.svg  Slovenia 64%
Flag of Spain.svg  Spain 67%
Flag of Sweden.svg  Sweden 90%
Flag of Switzerland (Pantone).svg   Switzerland 92%
Flag of the United Kingdom.svg  United Kingdom 82%
Flag of Europe.svg  Europe 76.1%

Challenges

Aside from recycled aluminium beverage cans, the majority of recycled aluminium comes in a mixture of different alloys. Those alloys generally have high percentages of silicon (Si) and require additional refinement during the shredding, sorting, and refining process to reduce impurities. Due to the levels of impurities found after refinement, the applications of recycled aluminium alloys are limited to castings and extrusions. The aerospace industry often restrict impurity levels of Si and Fe in alloys to a 0.40% maximum. Controlling the appearance of these elements is increasingly difficult the more often the metal has been recycled and require higher cost operations for the alloys to meet performance requirements. [38]

Byproducts

White dross, a residue from primary aluminium production and secondary recycling operations, usually classified as waste, [39] still contains useful quantities of aluminium which can be extracted industrially. [40] The process produces aluminium billets, together with a highly complex waste material. This waste is difficult to manage. It reacts with water, releasing a mixture of gases (including, among others, hydrogen, acetylene, and ammonia) which spontaneously ignites on contact with air; [41] contact with damp air results in the release of copious quantities of ammonia gas. Despite these difficulties, however, the waste has found use as a filler in asphalt and concrete. [42]

See also

Related Research Articles

<span class="mw-page-title-main">Aluminium</span> Chemical element with atomic number 13 (Al)

Aluminium is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of 26Al, a more unstable isotope, leads to it being used in radiometric dating.

<span class="mw-page-title-main">Alloy</span> Mixture or metallic solid solution composed of two or more elements

An alloy is a mixture of chemical elements of which in most cases at least one is a metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Most alloys are metallic and show good electrical conductivity, ductility, opacity, and luster, and may have properties that differ from those of the pure elements such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties such as corrosion resistance or mechanical strength.

<span class="mw-page-title-main">Metal casting</span> Pouring liquid metal into a mold

In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold that contains a negative impression of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.

The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process applied at industrial scale happens at 940–980 °C and produces 99.5–99.8% pure aluminium. Recycling aluminum requires no electrolysis, thus it is not treated in this way.

<span class="mw-page-title-main">Steelmaking</span> Process for producing steel from iron ore and scrap

Steelmaking is the process of producing steel from iron ore and/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur, and excess carbon are removed from the sourced iron, and alloying elements such as manganese, nickel, chromium, carbon, and vanadium are added to produce different grades of steel.

The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. The aluminium oxide must be further purified before it can be refined into aluminium.

<span class="mw-page-title-main">Industrial processes</span> Process of producing goods

Industrial processes are procedures involving chemical, physical, electrical, or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry.

<span class="mw-page-title-main">Die casting</span> Metal casting process

Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminium, magnesium, lead, pewter, and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used.

<span class="mw-page-title-main">Scrap</span> Recyclable materials left over from manufactured products after their use

Scrap consists of recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap can have monetary value, especially recovered metals, and non-metallic materials are also recovered for recycling. Once collected, the materials are sorted into types – typically metal scrap will be crushed, shredded, and sorted using mechanical processes.

<span class="mw-page-title-main">Dross</span> Impurities in molten metal

Dross is a mass of solid impurities floating on a molten metal or dispersed in the metal, such as in wrought iron. It forms on the surface of low-melting-point metals such as tin, lead, zinc or aluminium or alloys by oxidation of the metal. For higher melting point metals and alloys such as steel and silver, oxidized impurities melt and float making them easy to pour off.

<span class="mw-page-title-main">Electric arc furnace</span> Type of furnace

An electric arc furnace (EAF) is a furnace that heats material by means of an electric arc.

<span class="mw-page-title-main">Foundry</span> Factory that produces metal castings

A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed.

<span class="mw-page-title-main">Investment casting</span> Industrial process based on lost-wax casting

Investment casting is an industrial process based on lost-wax casting, one of the oldest known metal-forming techniques. The term "lost-wax casting" can also refer to modern investment casting processes.

<span class="mw-page-title-main">Aluminium smelting</span> Process of extracting aluminium from its oxide alumina

Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall-Héroult process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery.

Semi-solid metal casting (SSM) is a near net shape variant of die casting. The process is used today with non-ferrous metals, such as aluminium, copper, and magnesium. It can work with higher temperature alloys that lack suitable die materials. The process combines the advantages of casting and forging.The process is named after the fluid property thixotropy, which is the phenomenon that allows this process to work. Thixotropic fluids flow when sheared, but thicken when standing. The potential for this type of process was first recognized in the early 1970s. Its three variants are thixocasting, rheocasting, and thixomolding. SIMA refers to a specialized process to prepare aluminum alloys for thixocasting using hot and cold working.

A casting defect is an undesired irregularity in a metal casting process. Some defects can be tolerated while others can be repaired, otherwise they must be eliminated. They are broken down into five main categories: gas porosity, shrinkage defects, mould material defects, pouring metal defects, and metallurgical defects.

<span class="mw-page-title-main">Aluminum industry in the United States</span>

The aluminum industry in the United States in 2023 produced 860 thousand metric tons of aluminum from refined metal ore, at six smelters. In addition, US industry recycled 3.4 million tons of aluminum . Total annual imports of metal and alloy for use in secondary production stood at 2.6 million metric tons in the year to August 2023, with the previous decade seeing a fundamental shift toward recycled production.

<span class="mw-page-title-main">History of aluminium</span>

Aluminium metal is very rare in native form, and the process to refine it from ores is complex, so for most of human history it was unknown. However, the compound alum has been known since the 5th century BCE and was used extensively by the ancients for dyeing. During the Middle Ages, its use for dyeing made it a commodity of international commerce. Renaissance scientists believed that alum was a salt of a new earth; during the Age of Enlightenment, it was established that this earth, alumina, was an oxide of a new metal. Discovery of this metal was announced in 1825 by Danish physicist Hans Christian Ørsted, whose work was extended by German chemist Friedrich Wöhler.

<span class="mw-page-title-main">Aircraft recycling</span> Recycling industry for aircraft

Aircraft recycling is the process of scrapping and disassembling retired aircraft, and re-purposing their parts as spare parts or scrap. Airplanes are made of around 800 to 1000 parts that can be recycled, with the majority of them made from metal alloys and composite materials. The two most common metal alloys are aluminum and titanium and the main composite material is carbon fiber.

Ferroaluminum (FeAl) is a ferroalloy, consisting of iron and aluminium. The metal usually consists of 40% to 60% aluminium. Applications of ferroaluminum include the deoxidation of steel, hardfacing applications, reducing agent, thermite reactions, AlNiCo magnets, and alloying additions to welding wires and fluxes. The alloy is also known for the ability to manufacture low melting point alloys and its ability to carry out aluminothermic welding. Ferroaluminum does not currently have a CAS Registry Number. The presence of iron in aluminum helps in the decrease of casting defects, improves tensile, yield, hardness, and maintains strength at high temperatures.

References

  1. ↑ Wallace, G. (2011-01-01), Lumley, Roger (ed.), "4 - Production of secondary aluminium", Fundamentals of Aluminium Metallurgy, Woodhead Publishing Series in Metals and Surface Engineering, Woodhead Publishing, pp. 70–82, doi:10.1533/9780857090256.1.70, ISBN   978-1-84569-654-2 , retrieved 2023-11-06
  2. ↑ "The price of virtue". The Economist. ISSN   0013-0613 . Retrieved 2023-11-06.
  3. ↑ "Aluminum Statistics and Information | U.S. Geological Survey". www.usgs.gov. Retrieved 2023-11-06.
  4. ↑ "Land, Waste, and Cleanup Topics". United States Environmental Protection Agency.
  5. 1 2 Falde, Nathan (2018-08-16). "How is Aluminum Recycled? Step by Step | Greentumble" . Retrieved 2023-11-06.
  6. 1 2 "Aluminum Recycling". American Chemical Society. Retrieved 2023-11-06.
  7. 1 2 3 Capuzzi, Stefano; Timelli, Giulio (April 2018). "Preparation and Melting of Scrap in Aluminum Recycling: A Review". Metals. 8 (4): 249. doi: 10.3390/met8040249 . ISSN   2075-4701.
  8. ↑ Provider, Aluminum Machinery Total Solution. "Seven things your competitors know about aluminum scrap pretreatment process". Brightstar Aluminum Machinery. Retrieved 2023-11-06.
  9. ↑ Vallejo-Olivares, Alicia; Høgåsen, Solveig; Kvithyld, Anne; Tranell, Gabriella (2022-12-01). "Thermal De-coating Pre-treatment for Loose or Compacted Aluminum Scrap and Consequences for Salt-Flux Recycling". Journal of Sustainable Metallurgy. 8 (4): 1485–1497. Bibcode:2022JSusM...8.1485V. doi: 10.1007/s40831-022-00612-x . hdl: 11250/3029143 . ISSN   2199-3831.
  10. 1 2 "Effective recovery & quality improvement of aluminium scrap • STEINERT". steinertglobal.com. Retrieved 2023-11-06.
  11. 1 2 "Aluminium Recycling – Processes". The International Aluminium Institute. Retrieved 2023-11-06.
  12. ↑ Yang, Yongxiang; Xiao, Yanping; Zhou, Bo; Reuter, Markus A. "Aluminium Recycling: Scrap Melting and Process Simulation". ResearchGate.
  13. ↑ "Aluminum Recycling and Secondary Processing". Light Metal Age Magazine. 2021-08-17. Retrieved 2023-11-06.
  14. ↑ dolincasting (2021-08-17). "Aluminum Casting Techniques and Processes". Dolin Aluminum Casting. Retrieved 2023-11-06.
  15. ↑ Fiore, S.; Zanetti, M. C.; Ruffino, B. (2005-09-01). "Waste characterization and recycle in an aluminium foundry". Resources, Conservation and Recycling. 45 (1): 48–59. Bibcode:2005RCR....45...48F. doi:10.1016/j.resconrec.2005.01.006. ISSN   0921-3449.
  16. ↑ Kvande, Halvor (2008-08-01). "Two hundred years of aluminum ... or is it aluminium?". JOM. 60 (8): 23–24. Bibcode:2008JOM....60h..23K. doi:10.1007/s11837-008-0102-3. ISSN   1543-1851. S2CID   135517326.
  17. ↑ Reverdy, Michel; Potocnik, Vinko (2020). "History of Inventions and Innovations for Aluminum Production". TMS 2020 149th Annual Meeting & Exhibition Supplemental Proceedings. The Minerals, Metals & Materials Series. Cham: Springer International Publishing. pp. 1895–1910. doi:10.1007/978-3-030-36296-6_175. ISBN   978-3-030-36296-6. S2CID   213788259.
  18. ↑ Habashi, Fathi. "Bayer's process process for Alumina Production: A Historical Perspective" (PDF). Bull. Hist. Chem.
  19. 1 2 Byers, Ann (2017-12-15). Reuse It: The History of Modern Recycling. Cavendish Square Publishing, LLC. ISBN   978-1-5026-3127-5.
  20. ↑ Bertram; Ramkumar; Rechberger; Rombach; Bayliss; Martchek; Müller; Liu (October 2017). "A regionally-linked, dynamic material flow modelling tool for rolled, extruded and cast aluminium products". Resources, Conservation and Recycling. 125: 48–69. Bibcode:2017RCR...125...48B. doi:10.1016/j.resconrec.2017.05.014 . Retrieved October 17, 2024.
  21. ↑ "International Aluminum Institute" (PDF). Archived from the original (PDF) on 2022-04-23. Retrieved 2010-02-09.
  22. ↑ "Sustainability – Recycling | Aluminum Association". www.aluminum.org. Retrieved 2023-11-06.
  23. ↑ "Manufacturing with Die Casting: An Eco-Friendly Option". NADCA Design. 2017-01-21. Archived from the original on 2022-10-07. Retrieved 2017-03-08.
  24. ↑ Khaji, Khalil; Al Qassemi, Mohammed (2016). "The Role of Anode Manufacturing Processes in Net Carbon Consumption". Metals. 6 (6): 128. doi: 10.3390/met6060128 .
  25. ↑ Clemence, Christopher (April 2, 2019). "Leaders Emerge In The Aluminium Industry's Race To Zero Carbon". Aluminium Insider.
  26. ↑ "Aluminium organisation: Environmental issues". Archived from the original on 2010-10-06. Retrieved 2010-11-28.
  27. ↑ "Why addressing the aluminium industry's carbon footprint is key". World Economic Forum. 2020-11-30. Retrieved 2023-11-06.
  28. 1 2 Reinsch, William Alan; Benson, Emily (2022-02-25). "Decarbonizing Aluminum: Rolling Out a More Sustainable Sector". Center for Strategic and International Studies.
  29. ↑ "Sustainability – Recycling". www.aluminum.org. Retrieved 2023-11-06.
  30. ↑ "Aluminum Can Life Cycle Assessment Report Overview" (PDF). 2021.
  31. ↑ "Recycling Economic Information (REI) Report". EPA United States Environmental Protection Agency. August 4, 2023. Retrieved November 6, 2023.
  32. ↑ Rajeev, Vikram (2021-08-10). "Economic Benefits and Circular Economy Leads to Rising Popularity of Aluminum Recycling in APAC". Frost & Sullivan. Retrieved 2023-11-06.
  33. ↑ "Which country is leading the circular economy shift?". www.ellenmacarthurfoundation.org. 2021-06-28. Retrieved 2023-11-06.
  34. ↑ "Aluminium Recycling Factsheet". International Aluminium Institute. October 2022. Retrieved 14 September 2022.
  35. ↑ "In 2009, Brazil was, once again, the leading country worldwide in the collection of aluminium beverage cans, with a recycling rate of 98.2%". Alu - Aluminium for future generations. 2010. Retrieved 2013-03-26.
  36. ↑ "Brazil's unemployed catadores keep recycling rates high while earning much-needed cash. - Free Online Library". Thefreelibrary.com. 2010-03-22. Retrieved 2012-11-15.
  37. ↑ "Aluminium beverage can recycling in 2021 at a new record level of 76%". metalpackagingeurope.org. Retrieved 15 May 2024.
  38. ↑ Das, Subodh K (2006). "Emerging Trends in Aluminum Recycling: Reasons and Responses" (PDF). Light Metals 2006. TMS (The Minerals, Metals & Materials Society).
  39. ↑ "Residues from aluminium dross recycling in cement" (PDF). Archived from the original (PDF) on 2018-08-26. Retrieved 2018-06-07.
  40. ↑ Hwang, J.Y., Huang, X., Xu, Z. (2006), Recovery of Metals from Aluminum Dross and Salt cake, Journal of Minerals & Materials Characterization & Engineering. Vol. 5, No. 1, pp 47-62
  41. ↑ "Why are dross & saltcake a concern?". Archived from the original on 2018-06-12. Retrieved 2012-01-13.
  42. ↑ Dunster, A.M., Moulinier, F., Abbott, B., Conroy, A., Adams, K., Widyatmoko, D.(2005). Added value of using new industrial waste streams as secondary aggregates in both concrete and asphalt. DTI/WRAP Aggregates Research Programme STBF 13/15C. The Waste and Resources Action Programme
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.