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| Fig. 1: Compressed Aluminum Cans. (Source: Wikimedia Commons) |
Back in the early 19th century, aluminum was considered a luxury material due to its extremely high price. This was not because of its scarcity, on the contrary, aluminum is the most abundant metal in the Earths crust. [1] The real challenge lay in extracting it. Aluminum can be very easily oxidized and rarely appears in elemental form in nature making its isolation difficult. Producing metallic aluminum required tremendous effort from chemists. Today, thanks to advances in extraction and refining methods, aluminum can be produced at a much lower cost. However, the process still demands a substantial amount of energy.
Since aluminum does not occur in its elemental form in nature, it must be extracted from its compounds. This extraction process is highly energy-intensive. The primary production of aluminum requires an average of 66 MJ per kilogram, with the reduction step accounting for about 80% of the total energy consumption. [2] However, much of this energy, along with the environmental impact of mining, can be avoided through recycling. Since used aluminum has already been reduced to its elemental form, only a minimal amount of energy is needed to reprocess it for reuse . Reported data indicates that only 1 MJ per kilogram is required for aluminum recovery using the solid-state recycling method. [2] Other source also reports similar values, suggesting an energy saving of approximately 95% compared to primary production. [3]
An additional estimation can be made for the potential cost savings: assuming an energy saving of 65 MJ per kilogram and an average U.S. industrial electricity price of 8.14 cents per kWh, the monetary saving from recycling aluminum is approximately $1.47 per kilogram. [4] Considering that the average market price of primary aluminum ingots in June 2025 was $1.72 per pound (equivalent to $3.79 per kilogram), electricity cost savings could substantially lower production costs, making recycled aluminum potentially economically competitive. [5] At the same time, we acknowledge that, in addition to saving electricity costs, aluminum scrap must be collected and sorted, which requires extensive labor and results in regional commodity prices for recycled aluminum cans as high as $1.7 per kilogram in 2024 (compressed aluminum cans' picture shown in Fig. 1). [6] This high cost may constrain the scale of aluminum recycling industry. To evaluate the combined impact of these factors, we present an example from a recycling company.
One of the leading aluminum recycling companies, Novelis, reported that it was capable of recycling 82 billion aluminum cans in 2022. [7] Assuming an average weight of 15 g per can, this corresponds to approximately 1.23 billon kilogram of recycled aluminum from cans alone. The same report indicated net sales of $17.1 billion for the 2022 fiscal year. [7] The scale of Novelis' business demonstrates that aluminum recycling is indeed economically sustainable business.
The above comparisons highlight the savings in both energy and costs achieved through aluminum recycling. Despite the high cost of aluminum scrap, the industry's large scale suggests that aluminum recycling remains financially profitable.
© Yidi Liu. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] D. Rabinovich, "The Allure of Aluminium," Nature Chem. 5, 76 (2013).
[2] S. Al-Alimi et al., "Recycling Aluminium For Sustainable Development: A Review of Different Processing Technologies in Green Manufacturing," Results Eng. 23, 102566 (2024).
[3] S. Capuzzi and G. Timelli, "Preparation and Melting of Scrap in Aluminum Recycling: A Review," Metals 8, 249 (2018).
[4] "Electric Power Monthly October 2025," U.S. Energy Information Administration, October 2025, Table 5.6 B.
[5]"Mineral Industry Surveys: Aluminum in June 2025," U.S. Geological Survey, September 2025.
[6] "Materials Recovery Facility Evaluation," County of Kawa'i, Hawai'i, June 2025, Table 4.3.
[7] J. Paben, "Novelis Unveils Plans For $2.5B Aluminum Recycling Plant," Resource Recycling, 11 May 22.
