New non-toxic method could revolutionise rare earth metal processing
May 14, 2025
A team of researchers from the US Department of Energy’s Ames National Laboratory, Iowa, USA, has developed a new, safer, scalable method for producing rare earth metals that utilises the Ames Process. The Ames Process was originally developed to produce high-purity uranium to support the Manhattan Project and remains an important and effective method for producing high-purity rare earth metals today.
This new method, Rare Earth Metals from Alternative Fluoride Salt (REMAFS), uses an alternative fluoride salt in the production of rare earth metals, replacing traditional salts made using harmful hydrofluoric acid (HF). Additionally, 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.
Ikenna Nlebedim, the deputy director of the Division of Critical Materials and a scientist at Ames Lab who led the research group, explained that by eliminating both the use and generation of HF, REMAFS 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,” Nlebedim said. “It can be prepared at room temperature, and it is very easy to scale, so you can produce large quantities of it.”
Scalability is often a challenge for researchers developing new materials and processes. It can be challenging to move from laboratory-scale to industrial-scale production, that would be necessary for use in industry applications.
Denis Prodius, the project lead and a scientist at Ames Lab, shared, “The ability to easily produce large quantities of materials for the REMAFS process is a key step toward commercial deployment.”
“Discussions around large-scale implementation are already underway with the licensee,” Prodius shared.
In addition to being easy to prepare and scale up to large quantities, the method can reduce the number of steps required to process rare earth elements before they can be transformed into metal. Trevor Riedemann, a research technologist at Ames Lab who is part of the research team, joined Nlebedim in explaining the details.
Rare earth elements are found in certain types of rocks, along with a mixture of other elements. These rocks are mined, crushed, and chemicals are added to concentrate the rare earth elements. At this stage, they are still in a mixture, like a chemical soup. Next, they go through a special process to separate them into their individual rare earth salts, which are subsequently turned into oxides. For the Ames process, before the rare earths can be turned into metals, the oxides are changed into their fluorides – another type of salt.
“You start with salt, convert it to an oxide, turn it again to a salt before you reduce the salt to metal,” Riedemann explained. “For the REMAFS process, we’re going from salt to metal and cutting out having to fully convert to the oxide and then go back to salt. If you can start at the salt and eliminate the oxide process completely, you’d be saving money.”
Nlebedim emphasised that their new method can start with materials either from the first salt stage, or with oxides, “So another unique thing about this process is that this feedstock is easier to make than the traditional feedstock, which eliminates the hazards associated with making those feedstocks.”
“Anytime you could avoid working with nasty chemicals, such as HF, it is something that is very good for everybody,” Nlebedim concluded.
