ADVANCED MATERIALS & PROCESSES | JULY/AUGUST 2025 13 PROCESS TECHNOLOGY NEW PROCESS REFINES METALS FROM WASTE ALLOYS Researchers from the University of Melbourne, Australia, and King Fahd University of Petroleum and Minerals, Saudi Arabia, report a discovery that could transform how metals are extracted and purified from crude metals and waste alloys. The technique is based on electrocapillary principles and enables selective separation of metals from liquid alloys using differences in their surface energy, a new concept in metallurgy. In molten alloys, certain invention of the Ames Process, which was originally developed to produce high-purity uranium for the Manhattan Project. The process remains an effective method for producing high-purity rare earth metals to this day. Now, a team of researchers at the lab’s Critical Materials Innovation Hub developed a safer and scalable method for pro- ducing rare earth metals that employs the Ames Process. The new method, Rare Earth Metals from Alternative Fluoride Salt (REMAFS), uses an alternative fluoride salt in the production of rare earth metals instead of tradi- tional rare earth salts made with hydrofluoric acid (HF). In addition, the method can be integrated earlier in the rare earth supply chain to reduce the number of steps required to convert mined materials to rare earth metals. Research scientist Ikenna Nlebedim explained that by eliminating both the use and generation of HF, the REMAFS method significantly improves safety, environmental impacts, and scalability. “This process uses rare earth fluoride, but instead of traditional rare earth fluoride, it uses sodium rare earth fluoride. The difference is that sodium rare earth fluoride can be prepared without hydrofluoric acid,” says Nlebedim. “It can be prepared at room temperature, and it is very easy to scale, so you can produce large quantities of it.” ameslab.gov. metals migrate to the surface, enriching the interface based on their surface energy levels. In the new process, crude metals and alloys can be dissolved into low- melting-point post- transition metals such as gallium to form liquid alloys that remain fluid at or near room temperature. When liquid alloys are placed in a special solution, they create a boundary layer. By applying a small electric charge to this layer, the surface tension of the alloy is reduced. This causes certain metals, specifically those with lower surface energy such as bismuth, tin, and lead, to move to the surface and separate from the mixture in a defined sequence. The process achieves high-purity metal separation without the need for high temperatures or harmful chemicals. Unlike conventional smelting or chemical extraction, the new method minimizes energy consumption and reduces environmental impact. “The commercial application of our metal expulsion technology is expected to utilize proven renewable energy sources for achieving a net- zero process. This discovery opens the door to sustainable metallurgy,” says lead researcher Mohannad Mayyas. www.kfupm.edu.sa. NONTOXIC METHOD FOR PROCESSING RARE EARTHS Scientists at the DOE’s Ames National Laboratory, Iowa, have been producing rare earth metals for over 75 years. An important aspect of this history is based on Harley Wilhelm’s Researchers at Cornell University, Ithaca, N.Y., developed an inexpensive and potentially scalable approach that uses a commercially available peroxide to bind polyethylene and polypropylene together, creating a more useful, highquality plastic recycling additive. cornell.edu. BRIEF The process of creating a liquid alloy surface slab model. Courtesy of Advanced Functional Materials, 2025, doi.org/10.1002/ adfm.202505583. The REFMAS process uses sodium neodymium fluoride salts and can result in the bonded magnet shown. Courtesy of Ames Lab.
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