Nanchang-based Study: Synergistic Removal of Rare Earth Elements from Radioactive Molten Salt

Highlights

• Researchers developed a two-step process combining electrodeposition and high-temperature adsorption to remove rare earth elements from radioactive molten salt.
• The method achieved 99.98% total removal efficiency for lutetium, demonstrating potential for sustainable nuclear waste management.
• The innovative technique could help reduce environmental impacts and support resource recovery in nuclear and rare earth industries.

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A recent study titled “Synergistic Removal of Rare Earth Elements from Radioactive Molten Salt via Electrodeposition and Adsorption,” was led by Yingcai Wang and Yunhai Liu, affiliated with Jiangxi Province Key Laboratory of Nuclear Physics and Technology, East China University of Technology, in Nanchang a group representing a hub of nuclear materials and sustainability. Published on January 25, 2025, by the American Chemical Society (opens in a new tab), the research addresses the challenge of recycling radioactive waste salt in the nuclear fuel cycle and reducing energy consumption during electrorefining processes.

Hypothesis and Study Design

The study hypothesized that a combination of electrodeposition and adsorption techniques could efficiently remove rare earth elements (REEs) from radioactive molten salt, improving sustainability in nuclear fuel reprocessing.

The researchers employed a two-step process involving 1) Electrodeposition: Lutetium (Lu) was selectively extracted from LiCl–KCl–LuCl₃ molten salt using constant potential electrolysis on a bismuth (Bi) electrode, achieving a 90.59% extraction rate, and 2) High-temperature adsorption: after electrolysis, the remaining waste salt was purified using 5A molecular sieves (5A), achieving an additional 99.70% removal efficiency for Lu.

To validate the approach, the team also tested the method on a mixture of rare earth elements, including yttrium (Y), holmium (Ho), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and observed significant removal rates for all these elements.

Findings

The combined approach of electrodeposition and adsorption yielded a total removal efficiency of 99.98% for lutetium. This high effectiveness demonstrates the method’s potential to recycle waste salt in nuclear fuel reprocessing while reducing electric energy requirements. Furthermore, the study highlights the approach’s applicability to other rare earth elements, suggesting its broader utility in waste salt purification.

Limitations

Like all studies, this one comes with limitations. Such limitations include scalability factors, material durability, selective removal, energy, and cost analysis factors.

Implications and Practical Applications

This study presents a promising dual-method approach to tackling two critical issues in nuclear waste management: recycling radioactive waste salt and recovering valuable rare earth elements (REEs). The nearly complete removal of lutetium and other REEs suggests potential applications in the broader nuclear fuel cycle, reducing environmental impacts and improving resource recovery.

However, future research must focus on scaling the process, evaluating its economic feasibility, and addressing additional contaminants in real-world scenarios.

If successful at scale, this technique could provide the nuclear and rare earth industries with an innovative tool to enhance sustainability, reduce waste, and support the growing demand for rare earth materials in green energy technologies.