Highlights
- Researchers develop novel sodium-rare-earth-fluoride (Na-RE-F) route that eliminates toxic hydrofluoric acid in rare earth metal extraction.
- New method produces neodymium metal with 70-80% yield and high purity, operating safely in ambient air.
- Breakthrough potentially challenges China’s dominance in rare earth refining and supports cleaner industrial practices.
A breakthrough study published last month led by Dr. Anirudha Karati (opens in a new tab) and colleagues at the Ames National Laboratory (opens in a new tab) offers a safer, scalable alternative to traditional rare earth metal production. Published in Nature Communications, the research replaces toxic hydrofluoric acid (HF)—a mainstay in current REE refining—with a novel sodium-rare-earth-fluoride (Na-RE-F) route that eliminates HF entirely.
The team hypothesized that Na-RE-F, specifically NaNdF₄ (sodium neodymium fluoride), could serve as a viable feedstock for producing rare earth metals through calciothermic reduction—without relying on HF or its derivatives. The work aimed to validate whether this alternative salt could deliver comparable yields and metallurgical quality, while significantly reducing health and environmental risks.
Study Design and Method
The researchers synthesized NaNdF₄ from three precursor salts—acetate, chloride, and nitrate—via a simple, room-temperature hydrometallurgical process. Crucially, the method produced no HF during drying, emitting only water vapor. The NaNdF₄ powders were then calciothermically reduced at ~880 °C to yield metallic neodymium (Nd).
Thermal analysis confirmed that NaF acts as an internal flux, lowering the reduction temperature below 900 °C. X-ray diffraction, thermogravimetric and differential scanning calorimetry, and mass spectrometry were used to characterize phase composition and evolved gases.
Key Findings
- No HF Evolution–All three salt formulations dried cleanly in air with no hazardous HF detected—validated via gas sensors and mass spectrometry.
- High Yields–Calciothermic reduction produced Nd metal with 70–80% yield and typical metallurgical purity (O, N, C impurities in acceptable ppm range).
- Safe and Scalable–The method avoids HF, operates in ambient air, and is compatible with various RE precursor salts—paving the way for decentralized RE metal production.
Implications
This HF-free process represents a critical innovation in rare earth metallurgy. With global policymakers pushing for cleaner industrial practices and secure supply chains, particularly in defense and EV magnet markets, this method offers a safer, regulation-friendly path to domestic REE production.
It also undercuts China’s dominance in rare earth refining, which hinges on fluoride-based wet chemistry and HF-intensive processing. For Western automakers, defense contractors, and magnet producers, the ability to scale rare earth metal production without toxic precursors is a strategic shift.
Conclusion
By replacing HF with Na-RE-F salts in REE metal production, Dr. Karati and team have provided a cleaner, safer foundation for rare earth supply chains. Investors and policymakers should pay attention: this could reshape how the West retools its rare earth infrastructure.
Citation:
Karati, A., Parmar, H., Riedemann, T., Besser, M., Prodius, D., & Nlebedim, I.C. (2025). Rare earth metals production using an alternative feedstock that eliminates HF. Nature Communications, 16, 4528. https://doi.org/10.1038/s41467-025-59468-w (opens in a new tab)
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