Mine Tailings Cobalt: The Hidden US Supply

Mine tailings cobalt, gallium, and germanium discarded at US hardrock mining sites could meet domestic demand for all three materials — without a single new mine permit — according to a technical review published by Idaho National Laboratory (INL) in April 2026. The report, authored by Robert Podgorney and colleagues, documents an estimated 13,904 million metric tons of tailings across 189 major US sites from the top ten commodity categories alone.

Mine Tailings Cobalt, Gallium and Germanium: What the INL Found

The INL assessment, prepared for the US Department of Energy under contract DE-AC07-05ID14517, compiled more than 300 datasets from over 100 organisations covering critical mineral content in mine waste. Its finding is direct: tailings generated by more than a century of hardrock mining contain recoverable quantities of materials that were either uneconomic to extract at the time or beyond the capability of then-current processing technology.

Arizona’s copper porphyry systems — including Sierrita, Bagdad, and Morenci — produced tailings containing not only residual copper but also gallium, germanium, cobalt, and indium. Missouri’s historic lead-zinc districts left behind materials containing cobalt, nickel, and germanium. Phosphate-mining operations in Idaho and Florida generated waste streams with rare earth elements, uranium, and thorium.

A separate analysis published in the journal Science by Colorado School of Mines in August 2025 reached a parallel conclusion across 54 active US metal mines: recovering less than 10% of cobalt currently being mined but not captured would be sufficient to supply the entire US battery market. For germanium — used in infrared optics and missile sensors — recovering less than 1% of the material already being extracted but discarded would eliminate import dependency entirely.

The Processing Barrier — and China’s Role

The INL report is explicit that the obstacle is not mineral availability but processing infrastructure. US import reliance exceeds 50% for more than half of the 50 minerals designated as critical. China dominates both extraction and processing for many of these materials, controlling an estimated 90% of global refining capacity for several technology metals.

For cobalt, the supply chain dependency runs through Chinese-owned processing facilities in the DRC and China itself, even where the ore originates in third countries. Gallium and germanium — both subject to Chinese export licensing requirements introduced in 2023 and 2024 — present a sharper immediate risk: the US currently has no domestic commercial-scale refining capacity for either element.

The INL report notes that tailings reprocessing offers a structural cost advantage over primary mining for certain minerals: the energy-intensive steps of rock excavation and initial comminution have already been completed. Economic modeling suggests lower operational costs than greenfield extraction in targeted scenarios — though this advantage narrows considerably for low-grade tailings requiring complex multi-element separation.

Barriers the Report Identifies

The INL assessment is not optimistic about near-term deployment at scale. Fewer than 10% of identified tailings datasets provide sufficient detail for investment decisions. Most existing data require digitisation, georeferencing, and laboratory validation. The report identifies the absence of a standardised national tailings database as the single most critical barrier to accelerating private-sector development.

Permitting timelines present a second structural constraint. Environmental impact statements for US hardrock projects have historically taken a median of four to five years, with total project permitting sometimes extending beyond that. Recent statutory reforms now set presumptive limits of two years for EIS processes and one year for environmental assessments — improvements that have not yet produced a track record at commercial scale.

The “companionality” problem adds a further complication: 61% of the evaluated metals in the INL dataset are primarily produced as byproducts rather than primary commodities. Mine tailings cobalt and gallium cannot simply be targeted for recovery in isolation — their economics depend on the broader project and host-metal price dynamics.

What the INL Recommends

The report’s nine recommendations include a National Mine Tailings Assessment Program to characterise sites across all major US mining districts within 12–18 months, creation of a publicly accessible database for project screening, production tax credits for critical minerals recovered from secondary sources, and government offtake agreements to provide price stability for initial commercial production.

It also calls for expanded national laboratory involvement in providing separation-science expertise and pilot-scale testing to reduce technical risk for private partners — a role INL itself has been building through its electrochemical membrane reactor programme and bioleaching research, which targets cobalt, nickel, lithium, and rare earth elements from battery leachates and mine waste.

For procurement professionals and supply chain managers tracking cobalt price exposure and Western supply alternatives, the INL report frames tailings reprocessing as a medium-term rather than near-term supply lever. Commercial-scale output from US tailings is a 2030s proposition at current policy and investment trajectories — but the resource inventory and technical feasibility are no longer in question.

For context on the top cobalt producers currently supplying the market, and on the China export controls applying to gallium and germanium, see related CMN coverage. Gallium and germanium price data is tracked on our sister publication, rare-earth-mining.com.

The full INL report — Critical-Minerals Recovery from Mine Tailings: A Technical Review and Strategic Assessment (INL/RPT-25-89279) — is available via the Idaho National Laboratory website.

This article is for informational purposes only and does not constitute investment advice.