What’s Holding Back Aluminum Recycling?

Please welcome back Ellie Gabel to the 21st Century Tech Blog. From childhood, she fell in love with science by reading magazines covering everything from astronomy to zoology. She is a big fan of Richard Dawkins. You can find more of her writing on her website.

In this, her fourth offering, she writes about aluminum. Aluminum, steel and concrete are the most widely used materials in construction and the building of infrastructure. Aluminum is second to steel as the most-consumed metal. Demand for the metal continues to rise with the industry in the face of pollution concerns seeking to deploy circular economic principles in standard practice. Ellie focuses on the critical issue of aluminum recycling. As always your comments are welcome. 

Globally, companies are closing the circular economy loop as consumers demand greater environmental accountability. However, manufacturers struggle to reach sustainability goals and recycling rates continue to lag. When you consider that aluminum of all three major building materials, the others being steel and concrete, has considerable advantages for the industry to lean into cutting-edge technologies and overhaul operations, it is unfortunate that recycling it isn’t much higher. 

Global Trends in Aluminum Recycling

Aluminum is everywhere, including food, containers and packaging, furniture, appliances and cars. The material is widely used because it has infinite recycling capacity, meaning it doesn’t break down or lose its properties over time. 

Using data from the Aluminum Association, the U.S. Environmental Protection Agency says aluminum accounted for 1.3% of total municipal solid waste generation in 2018 amounting to 3.9 million metric tons. About 1.9 million metric tons of the material was in containers and packaging. That same year, the recycling of aluminum amounted to only 34.9% mostly consisting of food and beverage containers. Landfills absorbed 2.7 million tons that year. 

China is the world’s largest consumer of aluminum. The country produces over 10 million tons annually accounting for one-third of the global total. While the International Aluminium Institute (IAI) reports a global recycling rate of 76%, the demand for aluminum is continuing to rise and is expected to increase 40% by 2030. That amounts to 33.3 million more tons and totals reaching 119.5 million.

If countries can increase their recycling rates, however, the IAI states deploying circular economic principles could meet increased demand through the recycling of 50%-60% of aluminum scrap.

Since it’s indestructible, aluminum changes form when it enters the natural world. For instance, it may attach to small particles and remain airborne for several days. Aluminum may dissolve in water and be absorbed by plants. 

Today, the average American adult inadvertently consumes 7 to 9 milligrams of aluminum daily. Small quantities are not harmful. Exposure to more significant amounts such as breathing in aluminum dust at work or living in proximity to mines, however, can cause lung and nervous system damage.

The Aluminum Recycling Conundrum

Low recycling rates, poor infrastructure and rising costs in material recovery operations make aluminum recycling challenging in the U.S. today. Obsolete technologies often mistake cans for landfill waste.

When discarded, aluminum intermixes with other materials, such as steel, cardboard and plastic, reducing its ability to be reused. Even proper sorting isn’t enough for the automotive and aviation industries that require more durable alloys combining aluminum with other materials. The Aluminum Association in the United States notes nearly 400 distinct wrought aluminum alloys exist each with separate processing requirements. That means each requires separate sorting when dealing with scrap.

One example is 3004 alloy aluminum which today is more recyclable than 5052 alloy aluminum making it an eco-friendly option for many industries. Aluminum 3004 is used in pipes, beverage cans and building materials, while 5052 alloys are widely used for boats, fuel tanks, cars and road signs. Another alloy, aluminum 3003 can be found in consumer goods and is used in chemical and food processing. Each requires a separate recycling process. 

Emerging Technologies in Aluminum Recycling

Cutting-edge technologies are improving aluminum recycling efficiency and sustainability. The best solutions start with optimized sorting processes that pinpoint the types of products in the waste stream and direct the sorting and separation to keep the metal out of landfills. 

X-ray transmission technology is proving effective in sorting materials according to atomic density, while developments in artificial intelligence (AI) are making separating and examining metals for purity more precise. These technologies can easily be integrated into existing infrastructure, preserving resources and lowering environmental impacts.

Another option is the deployment of cobots, collaborative robots. These devices use cameras, robotic arms and conveyor belts to transport and stack materials. They also scan, sort and operate safely using collision detection sensors.

Blockchain technology is also being used to improve waste management transparency, traceability and sustainability. Each transaction is recorded in real-time throughout the product life cycle including waste disposal, collection and transportation to recycling facilities to ensure compliance and prevent mismanagement. This makes recycling more cost-effective and operationally efficient.

Other solutions have deployed drones to detect safety threats in scrapyards. Drone cameras and sensors create 3D images of metal reserves, measure the volume and estimate the weight.

Another option is the generation of aluminum alloys with elevated impurity levels so the industry can incorporate more scrap materials into products and, as a result, reduce waste.

Industry Efforts to Create a Circular Economy

Amid increasing environmental issues and calls for sustainable goods and services, aluminum recycling is seen as an important issue. As a result, aluminum primary and secondary manufacturers are investing in new technologies. They are also implementing supply chain collaboration practices to close the circular economy further and help increase recycling rates. Overall, this is leading to widespread commitments to resource conservation and environmental stewardship to increase sustainability.

Government policies and regulations are also helping broaden aluminum recycling by setting mandatory recycling targets, establishing producer responsibility for end-of-life management, providing tax incentives and implementing deposit refund schemes.