Highlights

• Researchers from Colorado School of Mines found that U.S. mines already produce enough critical minerals in tailings to potentially meet domestic demand.
• Recovery of minerals like cobalt, lithium, and rare earths from waste streams is technically possible but faces significant economic and technological challenges.
• The study suggests U.S. mineral dependency is more a technological and economic constraint than a geological limitation.

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A new analysis led by Elizabeth Holley (opens in a new tab) and Priscilla Nelson (opens in a new tab) of the Colorado School of Mines, (opens in a new tab) along with colleagues and published in Science (Aug. 2025), claims that the U.S. already mines—then discards—enough critical minerals to meet nearly all domestic demand. The catch, Holley notes, is that these cobalt, lithium, gallium, and rare earths like neodymium and yttrium end up as tailings rather than products. On the surface, the claim is tantalizing: America’s mineral salvation lies in its waste streams. But what’s fact, what’s speculative spin, and where might bias seep in?

Solid Ground: What Holds Up

The core data approach is credible. Holley’s team built a database pairing production from federally permitted U.S. metal mines with geochemical concentration data from USGS, Geoscience Australia, and the Canadian Survey. This methodology is established in mining economics, and its conclusion—that valuable byproducts are lost in tailings—is undeniable. U.S. copper, zinc, and gold mines do generate streams rich in cobalt, germanium, and rare earths that are not currently recovered.

A Dash of Alchemy: Where the Speculation Creeps In

The leap from “present in tailings” to “easily recoverable” deserves more caution. Holley likens recovery to “getting salt out of bread dough”—an apt metaphor, but one that glosses over the enormous technical, economic, and regulatory hurdles in building separation facilities. Suggesting that recovering “less than 1%” of certain elements would eliminate imports risks overselling feasibility. Prices, processing costs, and technology readiness levels matter far more than concentration tables.

Policy Lens: Bias by Emphasis

The study’s framing—that U.S. dependency is a policy and R&D problem rather than a geological one—reveals a policy-advocacy angle. There’s an implicit push for government incentives and subsidies for recovery infrastructure. That position is defensible, but readers should note the bias: the research highlights opportunity more than obstacles, which could nudge policymakers and the public toward overestimating short-term supply security.

What’s Missing: The Investor Angle

The piece omits cost curves, timelines, and commercial reality. While lab-scale recovery of cobalt or germanium from tailings may be demonstrated, scaling it to market volumes requires billions in capex, permitting reform, and sustained price floors. Without those, tailings recovery risks remaining an academic talking point rather than an investable pathway.

Conclusion

Holley’s team provides a useful reframing: the U.S. is not geologically poor in critical minerals—it is technologically and economically constrained. The opportunity is real, but recovery is not a silver bullet. Investors and policymakers should treat this as a roadmap for potential rather than a promise of independence.

Citation: Holley, E. A., et al. “By-product recovery from US metal mines could reduce import reliance for critical minerals (opens in a new tab).” Science, August 22, 2025. DOI: 10.1126/science.adw8997

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