A vast and largely neglected source of rare earth metals, essential materials for clean energy, may be in our homes, in the back of our closets and in knick-knack drawers.
A new study by researchers in China and the Netherlands estimates that reusing or recycling rare earth metals from old cell phones, hard drives, electric motors and turbines could meet up to 40% of demand for these metals in the United States, China and in Europe by 2050.
It’s a promising prospect, especially for the United States, which relies heavily on imports of these materials, often just called rare earths. This dependence, industry experts say, could make American supply chains vulnerable to disruptions and geopolitical risks.
Rare earths are essential for green technology such as electric vehicles and wind turbines, which play a key role in the transition away from fossil fuels. They are also used in the aeronautical industry and in the manufacture of missiles and satellites.
Reusing and recycling rare earths can reduce the need for mining, an activity that can pollute soil and water with toxic heavy metals like arsenic. Rare earth mining operations have also been involved in local conflicts and human rights violations.
Being able to harness already mined rare earths would be another advantage of transitioning to renewable energy instead of burning fossil fuels, which cause global warming, said Peng Wang, a researcher at the Institute of Urban Environment of the Chinese Academy of Sciences and author main part of the study, which was published this month in the journal Nature Geoscience.
“Unlike fossil fuels, which are ‘burned’ and lost permanently once consumed,” he writes, rare earths “can be ‘recovered’ as an alternative source.”
The idea of reusing or recycling rare earths is not new. In the 1980s, Japanese researchers coined the term “urban mining” to describe collecting rare metals from discarded household appliances and electronic devices rather than extracting them from the earth.
Common metals such as iron, copper and aluminum are already widely recycled. But only about 1% of the rare earths in old products are reused or recycled, researchers estimate. The world relies instead on mining for its supply of rare earths — approximately 70% come from China, according to the United States Geological Survey.
For the latest study, researchers used modeling to predict how reusing and recycling rare earths could change this situation. Scientists concluded that the United States, the European Union and Japan could accumulate stocks of rare earths in their old electronics and other products that far surpass what they would find by mining the earth.
Based on their modeling, the researchers predicted that, globally, reuse and recycling could reduce the need to mine neodymium — a rare earth element used in wind turbines — by 60% by 2050 compared to a business baseline. as usual. For dysprosium, also used in wind turbines, that number was 67%.
The opportunity is there, but some big challenges lie ahead.
Rare earths are often combined with other metals, so extracting these metals can be difficult. Some rare earth recycling methods require dangerous chemicals and a lot of energy.
Extracting the few grams, or even milligrams, of rare earths present in every ancient product can be a daunting task. And there aren’t many systems for collecting old electronics and other items.
Scientists are working to advance recycling techniques. Researchers at the energy department’s Critical Materials Innovation Hub at Idaho National Laboratory, for example, are developing ways to use microbes instead of toxic chemicals to extract rare earths from ancient products.
Companies like Apple are developing robots that help recover critical materials, including rare earths, from old iPhones. In the US, 25 states and the District of Columbia already have recycling laws that require the collection of some used electronics, although most of the rare earths in these electronics are not recycled.
“We already have a supply, but we’re landfilling a lot of it, or it’s in people’s homes, on cell phones in a drawer somewhere,” says David Reed, a scientist who leads reuse and recycling research at Idaho National Laboratory.
“The challenge is to collect and process it, and I don’t know if there will be a miracle solution,” he says. “But there’s a lot of research going on, a lot of interest.”