According to a new study from the University of Michigan in Ann Arbor, North America has enough deposits of rare earth elements of sufficient quality to meet the needs of multiple industries.
Rare earth elements are critical components in 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, wind turbines, and battery electric vehicles, the study shows.
The researchers, led by U-M scientists Stephen Kesler and Greg Keoleian, estimate worldwide demand for rare earth minerals will increase to 123 kilotons in 2030 and 150 kilotons in 2040 from 91 kilotons in 2024.
However, the U.S. currently accounts for about 11 percent of rare earth element mining, while China accounts for about 70 percent 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,” says 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., was published in Resources, Conservation & Recycling.
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 says.
“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 says.
“The bottom line is 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 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 says.
Until about the 1980s, the U.S. mined rare earth elements with regularity at Mountain Pass in California, but it 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, says 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 says. “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 study co-authors include Christian Hitt and Jacob Cieply of the U-M Center for Sustainable Systems and Hyung Chul Kim, Robert DeKleine, and James Anderson at Ford Research and Innovation Center in Dearborn.
To access the study, visit Onshoring North American rare earth mining.
