Highlights
- Mahamadou Traoré's thesis exposes radioactive risks in rare earth element extraction, tracking uranium, thorium, radium, and lead distribution.
- Sulfuric acid baking process reveals complex radionuclide behavior, with 83% REE dissolution and selective radionuclide separation potential.
- Study warns that clean energy supply chains could become radioactive liabilities without effective separation and containment strategies.
A newly published master’s thesis by Mahamadou Traoré (Université du Québec en Abitibi-Témiscamingue) exposes a critical yet underexplored risk in North America's rare earth element (REE) supply chain: the distribution of radioactive contaminants—specifically uranium-238, thorium-232, radium-226, and lead-210—through REE extraction and processing workflows.
While REEs are vital to clean energy, defense, and tech manufacturing, the radioactive byproducts embedded in many deposits raise serious social, environmental, and regulatory concerns. This study represents one of the first systematic efforts to trace radionuclide behavior across the full processing chain—from flotation to sulfuric acid baking—using Quebec REE ore as the test case.
Key findings include:
| Finding | Summary |
|---|---|
| Thorium mirrors REE behavior | During flotation, 53.5% of REEs were recovered—matching the concentration of thorium-232—suggesting thorium is retained in the same stream as valuable REEs, complicating downstream processing and waste management |
| Uranium remains distributed | Uranium-238 levels remained stable across feed, concentrate, and tailings, indicating it neither concentrates nor separates predictably—creating disposal ambiguity. No radioactive leaching during flotation: None of the radionuclides dissolved into solution during flotation, reducing immediate environmental risk at this stage |
| Sulfuric acid baking selectively solubilizes REEs | At 350°C with 225% acid dosage, 83% of REEs were dissolved—alongside 80% of uranium, 60% of radium, and 57% of lead, while thorium dissolution was minimized (2.3%). Efficient radionuclide removal is possible: Neutralization with magnesium oxide precipitated nearly all dissolved thorium and iron, offering a promising treatment path |
Implications
As Canada and the U.S. rush to scale domestic REE production, this research sounds a clear alarm: radioactive contaminants cannot be ignored. Effective separation, containment, and regulatory strategies will be essential. Without them, “clean” energy supply chains risk becoming radioactive liabilities.
Source: Traoré, M. (2025). Université du Québec en Abitibi-Témiscamingue. Full study (opens in a new tab).
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