Aluminum (spelled “aluminium” outside of the United States and Canada), is a highly recyclable metal that is widely recycled across much of the world.
Alongside glass and steel, aluminum is one of the easiest to recycle materials on the planet. According to the Aluminum Association, nearly 75 percent of all aluminum that has ever been produced is still in use to this day; with the majority of aluminum cans that you purchase in a store having already been recycled many times over.
This isn’t to say aluminum is easy to produce. It takes a significant amount of energy to make virgin aluminum. Extracted and refined from mined bauxite ore, producing virgin aluminum is, in the words of Pieterjan Van Uytvanck and Uday Patel in Forbes, a “complicated, costly and energy-intensive,” process, with Van Uytvanck and Patel calculating that it takes an average of 14,000 kWh of electricity to produce just one metric tonne of aluminum.
While the environmental impact of producing aluminum may be significant, the benefits of recycling aluminum are clear. The reason why three-quarters of all aluminum that has ever been produced is still in use to this day is simple; aluminum recycling represents the circular economy at its finest. One of the most widely recycled materials in the world (and among the easiest to recycle), aluminum it is an almost perfect example of a true closed-loop circular solution.
So, what is the aluminum recycling process, and how is aluminum recycled in the first place?
How is Aluminum Recycled?
Aluminum is recycled by being shredded into chips and fed through an infrared sorter to remove any plastic, glass, or other contaminants, followed by a magnet which picks up any scraps of steel. The aluminum chips are then melted down at a temperature of approximately 1,221°F (660.3°C) into molten aluminum, and poured into large molds to create ingots.
During the remelting process the paint and lacquer on the cans are vaporized, and an aluminum oxide called dross is produced when the aluminum chips melt and reacts with air. In order to remove the dross, a furnace operator uses a large, machine-powered spatula to skim this dross off the top. This dross is collected, and then goes through its own aluminum recycling process in order to extract residual aluminum from the aluminum oxide.
In order for the molten aluminum to be turned into ingots it must first flow downhill into a large holding furnace. This furnace is then tipped on its side in order so the molten aluminum can be poured into ingot molds set into the ground.
It takes just two and a half hours for a 32.8 ft (10 meter) long ingot to set. Weighing 29.8 tons (27 metric tonnes), each ingot can contain upwards of 1.5 million aluminum cans.
After an ingot has been lifted out of its mold it is transported by truck to a rolling mill, in which it is heated in a furnace to 995°F (525°C). While this temperature is approximately 225°F below aluminum’s melting point, it is hot enough to relax the bonds between the aluminum atoms within the ingot. The ingot is then passed between a series of rollers that progressively roll the aluminum ingot thinner and thinner, much as you may have done while making fresh pasta, until the ingot becomes a sheet of aluminum approximately 0.1” (0.25mm) thick. At this point the aluminum sheet is rolled into a reel approximately 1,000 times its original length. This aluminum sheet is now ready to be reused.
Aluminum Can Recycling
According to the Environmental Protection Agency (EPA), the largest source of aluminum scrap in municipal solid waste collection is aluminum cans and other packaging, including aluminum foil. Of this, the majority of it is recycled back into aluminum cans.
When it comes to aluminum can recycling, it’s helpful for your local materials recovery facility (MRF) if you place your cans in your curbside recycling container if your city has a mixed recycling program, instead of throwing them in the trash. As I noted in Reader’s Digest, I strongly recommend against crushing aluminum cans, as doing so can cause sorting difficulties as machinery at your local MRF may not be able to distinguish between a crushed aluminum can and another flat recyclable item, such as paper or cardboard.
An aluminum can can go from end use to a brand new can rolling off the conveyor at an aluminum can recycling center in as few as 60-90 days. This is an extremely impressive turnaround process, and is just one of the reasons why aluminum can recycling (and aluminum recycling in general) is such an essential practice.
Aluminum Recycling Saves Energy
I mentioned at the beginning of this article that 75 percent of all aluminum that has ever been produced is still in use to this day. There’s a simple, and economical, reason for this.
While it is expensive and energy-intensive to extract and refine virgin aluminum from mined bauxite ore, recycling scrap aluminum requires just five percent of the energy needed to produce virgin aluminum, resulting in a 95 percent energy saving to use recycled aluminum over virgin material; a rarity in the world of recycling.
Before widespread commercial aluminum recycling, aluminum used to be one of the most expensive metals on the planet; more so than gold.
As historical writer Yuval Noah Harari notes in Sapiens, “Separating [aluminum] from its ore [used to be] extremely difficult and costly. For decades, aluminum was much more expensive than gold. In the 1860s, Emperor Napoleon III of France commissioned aluminum cutlery to be laid out for his most distinguished guests. Less important visitors had to make do with the gold knives and forks.”
The reason for this high cost came down not to the availability of the metal—aluminum is the most common metal found in the Earth’s crust—but rather the fact that it is extremely difficult to extract aluminum from the rock around it. For this reason, aluminum (and other metal) drives have been common wartime pushes throughout history, with the United States’ efforts during World War II depicted here.
Aluminum Recycling Rates Around the World
Aluminum recycling rates around the world have, for the most part, continued to improve with time. A September, 2019 report by The Aluminum Association found that the consumer recycling rate for aluminum cans recycling in the United States is 45.2 percent, whereas the industry recycling rate is 63.6 percent. Similarly, a June 2018 report by European Aluminium found that the overall aluminum can recycling rate for Europe was 76.3 percent in 2015.
Countries with the highest aluminum recycling rates include Poland, which had a 80.5 percent recycling rate in 2015 (albeit down from 90.9 percent in 2006), and Brazil, which reached an astonishing 98.4 percent aluminum can recycling rate in 2014.
The Future of Aluminum Recycling
While aluminum prices have fluctuated in recent years due to geopolitical issues that have impacted supply, the future of aluminum recycling remains bright.
One of the steadier commodities in the recycling stream, aluminum’s relative light weight and almost endless potential to be recycled has meant that while plastics remain the container of choice for many drink manufacturers, moves to place more and more beverages, including water, in aluminum cans are currently taking place.
Here at Rubicon our company mission is to end waste, in all of its forms. The future of aluminum recycling will be shaped by companies, cities, and individual residents who are willing to work to bring forward a true circular economy.
At Rubicon we are experts at creating aluminum (and other metals, including steel, copper, and iron) recycling solutions for businesses.
If you have any questions, or you are interested in learning more about Rubicon’s sustainability services, please contact us today.
Meredith Leahy is a Waste Diversion Manager at Rubicon. To stay ahead of Rubicon’s announcements of new partnerships and collaborations around the world, be sure to follow us on LinkedIn, Facebook, and Twitter, or contact us today.
