Study: Onshoring North American rare earth mining (DOI: 10.1016/j.resconrec.2026.109027)
In the quest to create a robust supply chain of rare earth elements necessary for the clean energy revolution and everyday modern conveniences, North America has enough deposits of sufficient quality to begin looking in its own backyard, according to a University of Michigan study.
Rare earth elements are critical components of many products in our lives, including cell phones, car batteries, computers, flat screen televisions and in the batteries that store energy generated by renewable sources. About half of rare earth elements mined today are used for magnets in products ranging from fighter jets to wind turbines and battery electric vehicles, the study shows.
The researchers, led by U-M scientists Stephen Kesler and Greg Keoleian, estimate that worldwide demand for rare earth minerals will increase from 91 kilotons in 2024 to 123 kilotons in 2030 and 150 kilotons in 2040. However, the U.S. only accounts for about 11% of rare earth element mining, while China accounts for about 70% of this mining.
Evaluating 28 sites across North America, the researchers found that the sites contain enough rare earth elements to produce more than the U.S. needs for the next few decades, but only some of the deposits can be mined economically.
"With this study, we are trying to give a framework of information that might allow a more systematic evaluation of deposits, and to avoid an overconcentration of support for deposits which might not, in the long run, be competitive," said Kesler, professor emeritus in the U-M Department of Earth and Environmental Sciences.
"Environmentally, we don't want to do any more mining than necessary, and if you have too much production, then the price drops and everyone goes out of business. This is a situation in which a little bit of government oversight in terms of funding and encouragement can help to develop a stable industry."
The study, supported by Ford Motor Co., is published in Resources, Conservation & Recycling.
Making the grade
To determine the quality of these mineral deposits, the researchers examined tonnage, grade and total rare earth oxide content at each site. Tonnage refers to how much rare earth-bearing rock is present in the ground, while grade refers to concentration of the targeted elements in the rock.
The researchers also evaluated what other minerals and elements might be present that could complicate the mining process. For example, thorium, a radioactive element, is often found in rare earth deposits and is costly to dispose of safely, Kesler said.
"Our results show that all of the deposits in North America, with the exception of the Mountain Pass mine in California that is already in operation, are of lower quality than those that are in operation in China and Australia. But that doesn't mean they can't be produced," Kesler said. "The bottom line is that the deposits are close enough in quality that they might be able to support a domestic supply chain with a little government support, particularly if the prices remain high. The increased costs of mining rare earths in a supply chain of this type might be offset by savings in other parts of the processing and manufacturing stages."
Kesler and Keoleian also characterized the types of rare earth elements available at each site. Rare earth elements are broadly categorized into two groups: light rare earth elements and heavy rare earth elements. Light rare earth elements are more abundant and are used in a wide range of products. Light rare earths have excellent magnetic properties while heavy rare earth elements are valuable because they improve the magnet's stability at high temperatures, Kesler said.
The researchers found that the sites in the United States contained mostly light rare earth elements, while the heavy rare earth elements were concentrated in Canada.
"For light rare earths, the U.S. could do a good job of supplying itself, and for heavy rare earths, we would do best to cooperate with Canada," Kesler said.
Why do we need to mine?
Until about the 1980s, the U.S. mined rare earth elements with regularity at Mountain Pass in California, but that mining declined as mining in China increased. In addition to developing domestic mine operations, it's important for the U.S. to establish its own processing infrastructure and fully integrated supply chain, said Keoleian, professor of sustainable systems at U-M's School for Environment and Sustainability. Previously, rare earth elements mined in the U.S. were exported to China for processing.
"One reason rare earth elements are classified as critical minerals is because of their vital importance for multiple industrial and technology applications as well as national defense," Keoleian said. "But they also pose a supply chain risk, and disruption of the supply chain could have significant economic and national security consequences. And they're essential inputs for the clean energy transition."
The study was conducted in conjunction with scientists at Ford Motor Co. Next, the researchers plan to examine the adequacy of the domestic rare earth supply for meeting demand for electric vehicles and other applications through 2050. That analysis is focusing on the U.S. deposits characterized in this study, their processing and the recovery rates of four rare earth elements-neodymium, praseodymium, dysprosium, and terbium-used in magnets.
Other co-authors include Christian Hitt and Jacob Cieply of U-M Center for Sustainable Systems and Hyung Chul Kim, Robert DeKleine and James Anderson of Ford Motor Company's Research and Innovation Center.
