By Erich Kirshner, Colorado School of Mines
September 10, 2025

Critical U.S. minerals are already mined but discarded. Small-scale recovery could meet demand and cut waste.

According to a new study published in Science, existing U.S. mines already produce all the critical minerals needed each year for energy, defense, and technology.

The problem, explained Elizabeth Holley, associate professor of mining engineering at the Colorado School of Mines and lead author of the study, is that these resources are not being recovered. Instead, minerals such as cobalt, lithium, gallium, and rare earth elements, including neodymium and yttriu,m are being discarded in the waste streams of other mining operations, such as those for gold and zinc.

“The challenge lies in recovery,” Holley said. “It’s like getting salt out of bread dough – we need to do a lot more research, development, and policy to make the recovery of these critical minerals economically feasible.”
Data-driven analysis of U.S. mines

To carry out the study, Holley and her colleagues created a database documenting annual output from federally permitted metal mines across the United States. They then applied a statistical resampling method to combine this production data with geochemical measurements of critical minerals in ores, compiled by the U.S. Geological Survey, Geoscience Australia, and the Geological Survey of Canada.

Through this method, the researchers were able to estimate how much of these critical minerals is produced and processed at U.S. mines each year but ultimately not recovered. Instead, these valuable resources are being discarded as mine tailings, which must then be stored and managed to reduce the risk of environmental pollution.

“This is a brand-new view of ‘low hanging fruit’ – we show where each critical mineral exists and the sites at which even 1 percent recovery of a particular critical mineral could make a huge difference, in many cases dramatically reducing or even eliminating the need to import that mineral,” Holley said.

Recoverable elements and potential impacts

The analysis in Science looks at a total of 70 elements used in applications ranging from consumer electronics like cell phones to medical devices to satellites to renewable energy to fighter jets and shows that unrecovered byproducts from other U.S. mines could meet the demand for all but two – platinum and palladium.

Among the elements included in the analysis are:

Cobalt (Co): This shiny bluish-gray metal, essential for manufacturing electric vehicle batteries, is produced as a secondary material during nickel and copper mining. Recovering under 10 percent of the cobalt that is currently mined and processed but left unrecovered would be sufficient to supply the entire U.S. battery industry.

Germanium (Ge): A brittle, silvery-white semi-metal used in electronics and infrared optics, including sensors for missiles and defense satellites, is found in zinc and molybdenum deposits. By reclaiming less than 1 percent of the germanium already mined and processed but not recovered in the U.S., domestic demand could be fully met without relying on imports.

Environmental and policy opportunities

The benefits of enhanced recovery are not only economic and geopolitical but also environmental, Holley said – recovering these critical minerals instead of sending them to tailings piles would reduce the environmental impact of mine waste and open more opportunities for reuse in construction and other industries.

“Now that we know which sites are low-hanging fruit, we need to conduct detailed analyses of the minerals in which these chemical elements reside and then test the technologies suitable for recovery of those elements from those specific minerals,” Holley said. “We also need policies that incentivize mine operators to incorporate additional processing infrastructure. Although these elements are needed, their market value may not be sufficient to motivate operators to invest in new equipment and processes without the right policies in place.”