Why it matters: A new analysis published in Science suggests that the US could significantly reduce its reliance on imported critical minerals by recovering resources currently discarded at domestic mining sites. These metals, including cobalt, lithium, germanium, and rare earth elements, are essential for industries ranging from energy and defense to electronics. Yet most end up in mine tailings alongside minerals such as gold and zinc, rather than being extracted for reuse.
Researchers led by Elizabeth Holley, an associate professor at the Colorado School of Mines, conducted a nationwide assessment of federally permitted metal mines. By combining mine production records with geochemical data from agencies such as the US Geological Survey, Geoscience Australia, and the Geological Survey of Canada, Holley's team estimated that nearly all the critical minerals required annually for US manufacturing are already present in domestic mining streams – they just aren't being captured.
The study used statistical resampling techniques to match mine output with mineral content data, revealing a major opportunity to redirect what is now considered industrial waste toward domestic supply. Of the 70 elements surveyed, the researchers found that with targeted recovery, the US could eliminate most imports for these resources, except for platinum and palladium.
One key example is cobalt, essential for electric vehicle batteries, which occurs as a byproduct in nickel and copper mining. The report concludes that recovering less than 10 percent of the cobalt currently lost would meet the entire demand of the US battery sector. Similarly, germanium – critical for sensors and satellite technology – could be sourced from zinc and molybdenum mining waste, with less than one percent recovery sufficient to satisfy national needs.
Despite the promise, recovery remains costly and technically complex. The metals are locked in tailings, mineral waste piles that require careful handling to prevent environmental contamination.
Holley likened the challenge to extracting salt from bread dough, a vivid illustration of why advances in separation technologies and supportive policy measures are needed to make mineral recovery economical. She emphasized that without proper incentives, mine operators may see little reason to invest in additional processing equipment, as the market value of these byproducts often falls short of justifying the expense without regulatory or financial backing.
Control over critical minerals has become a central concern for US policymakers following years of Chinese dominance in global supply chains. Other nations, including Australia, Canada, and members of the European Union, are pursuing similar strategies to reduce dependence on Chinese metals through domestic mining expansion and strategic stockpiling.
In the US, 54 active mining operations scattered across the country contain significant quantities of metals that could be reclaimed. Beyond copper and lithium, the study highlights opportunities to recover iron, molybdenum, silver, nickel, zinc, and rare earth elements from existing waste streams, potentially meeting or even exceeding current manufacturing demand. Rare earths, indispensable for producing powerful magnets used in renewable energy systems and defense technologies, represent a particularly important target.
Ultimately, the findings offer what Holley describes as a new view of low-hanging fruit: the opportunity to reclaim valuable minerals that are already being mined but lost as industrial waste.