The technology that is an essential part of clean energy and the future economy relies heavily on critical minerals. Electric vehicles (EVs), computers, wind turbines, and even defense technology require large mineral inputs, raising concerns over the stability of supply chains and the ability to meet growing demand. An IEA report published in 2021 predicts that demand for critical minerals will escalate over the next two decades, with increases of “40 percent for copper and rare earth elements, 60 to 70 percent for nickel and cobalt, and almost 90 percent for lithium.”

This shift towards mineral-based energy systems and technologies will pose a different set of challenges than those presented by today’s fossil fuel-based energy system. At present, the primary concern with growing demand for critical minerals is sustaining supply to meet the anticipated boom, particularly when taking ambitious climate goals into account—and doing so in safe, reliable, and sustainable ways. The IEA predicts that meeting future demand will require doubling current mineral inputs for clean energy technology by 2040. Yet achieving net-zero 2050 goals would require six times the amount currently used globally.

Bridging the gap between demand and supply has brought attention to the prospect of recycling critical minerals from secondary sources. While the clean energy transition will undoubtedly require greater mining, recycling will play a role in sustaining future mineral supply. Like fossil fuels, minerals are inherently finite, so finding innovative ways to reduce reliance on mining raw minerals will be critical to meeting the future demands of clean energy.

But how will this be accomplished? Two secondary sources of minerals hold the most promise: recycling from end-of-life products and recycling from mine waste tailings.

End-of-Life Product Recycling

The most widely discussed application for mineral recycling from end-of-life products is EVs batteries. By 2030, an “influx” of spent batteries from EV will create the need for a robust recycling industry to manage them.

Building effective EV recycling programs must overcome significant barriers, however. Existing EV batteries run on a 10- to 20-year cycle, so it could take several decades until there are enough to create a sufficient supply for the recycling industry. Additionally, the variability in design and composition of batteries, the lack of existing collection and manufacturing infrastructure, and the lack of data regarding the quality of reused batteries all make it difficult to scale up recycling processes.

The process of battery recycling is also very much still in the development phase. Extracting minerals from used lithium-ion batteries often occurs through hydrometallurgy—which involves placing the battery’s cathode in a solution to separate the minerals out, or pyrometallurgy—the use of high temperatures to achieve the same end. The relative complexity and demands of these processes mean that, at present, it is still more cost effective to mine new minerals than to recycle them. Tipping this scale would require broad industrialization of the recycling process and major policy incentives. Additionally, while cobalt and nickel can be continually reused, it is still uncertain if recycling will diminish the quality of other critical minerals.

Yet even overcoming extraction barriers, the IEA predicts that, “by 2040, recycled quantities of copper, lithium, nickel and cobalt from spent batteries could reduce combined primary supply requirement for these minerals by about 10 percent.”

These barriers may prove even more challenging in other areas of consumer technology where end-of-life recycling has been underdeveloped, such as headphones, smartphones, TVs, and the neodymium magnets used in wind turbines. There is wide variability in the quantity and quality of these secondary sources of minerals. And, like EV batteries, these technologies are not designed to be recycled, making extraction difficult.

Despite the barriers, consumer technology has the potential to be a large secondary source of rare earth minerals (REEs) as well as other critical minerals.

Currently, global REE and lithium recycling sit at about 0.2 percent and 0.5 percent, respectively, which is well below other minerals. These numbers will grow as end-of-life recycling gains traction and as technology and manufacturing progress, but policy incentives will be crucial for overcoming these initial barriers to growing end-of-life recycling.

Recycling the Byproducts of the Mining Process

While end-of-life mineral recycling has received the greatest attention, there is growing research around recycling minerals from mine tailings—a fine-grained material produced as a byproduct of mining. Uses for mine tailings in areas such as construction and cement production, agriculture, and other purposes have emerged, including the potential for recovering critical minerals from tailings.

The tailings from coal, iron, uranium, and bauxite mines have been found to contain concentrations of critical minerals extracted as byproducts of the mining process. The primary motivation for seeking minerals from these mine tailings is that the cost of reprocessing them is much lower than raw extraction, and the overall process to do so is much quicker.

There is promising research that advances the identification of these secondary deposits. In the abandoned iron mines of New York’s Adirondack Mountains, scientists analyzed both tailings and ore, finding REE concentrations up to 2.2 percent for the tailings and 4.8 percent for the ore. Considering the waste-to-extraction ratio is large for rare earths, these percentages are not insignificant. Additionally, research on recycling mine waste tailings is also underway in South Africa, Australia, and Sweden. Estimates vary, but the value of minerals in tailing storage facilities worldwide is close to $3.4 trillion.

Yet several concerns arise when it comes to sourcing REEs from mine tailings. First, the critical minerals found in tailings are often low-grade and vary in quantity. Second, extraction methods such as bio- and hydrometallurgy, while successful thus far, have yet to be applied broadly. Third, there is no applicable system for sourcing minerals from mine tailings, which inhibits the practice from becoming commercialized.

If mine tailings are to be an effective secondary source of critical minerals, significant research and development are needed to understand their economic viability. Fortunately, these investments are emerging in some areas, including the Department of Energy’s $140 million investment in a first-of-a-kind mine waste refinery.

Recycling in Its Global Context

Global investments in recycling are growing. The U.S. government has provided loans to bolster recycling, including nearly $2 billion to Redwood Materials to build out its current programming, as well as a $375 million loan for a battery recycling plant in New York. South Korea, Japan, and China are also making significant strides toward industrial mineral recycling, and the EU is ramping up its waste collection and mineral recycling capacity.

Yet while the need for mineral recycling is growing, prompting research and development that will help reduce future raw mineral mining, it is not a panacea. As Duncan Wood, Vice President for Strategy and New Initiatives at the Wilson Center, observed in his testimony before the U.S. Senate, growing demand will require a greater input of raw minerals. Growth in the recycling industry, then, is intimately tied to growth in mineral mining. But the present inability of critical minerals recycling to meet growth in demand does not make it a negligible practice.

The inevitable development of global mineral resources will also bring significant environmental and social impacts, which makes efforts to reduce the reliance on raw mineral mining even more important. Mineral extraction has a number of health hazards associated with it, such as air pollution from mine dust or exposure to hazardous materials that can impact local communities. Mining also has ecological consequences, such as land-use change and ecosystem pollution.

Furthermore, mineral mining, particularly for neodymium and lithium, is water-intensive. According to the IEA, over 50 percent of current lithium deposits are located in places prone to water stress, making water access one more dynamic in the already vulnerable global lithium supply chain. As the proliferation of critical mineral mining takes off, environmental and social impacts connected to mining are likely to grow in tandem.

Mining is also a global development issue. The development of a country’s resources has not always led to broader economic growth, perpetuating the “resource curse.” Growth in developing countries’ mining industries will also saddle them with large amounts of waste. For REEs alone, every ton extracted also generates 2,000 tons of waste and around 1 ton of radioactive material.

Implementing circular methods and effective post-extraction policies to deal with mine waste will be critical to avoiding previous global resource development pitfalls. Even a marginal reduction in the mining of raw minerals over the long term could reduce the hazards faced by countries producing critical minerals for the global economy.

As the world moves towards clean energy, it is critical to recognize that growth in mineral recycling will only follow a fantastically large growth in mining. Even if recycling cannot remedy the issues with growing demand for critical minerals, it can improve the margins of the clean energy transition by reducing reliance on mining and thereby reducing the costs associated with extraction.