KU Leuven Expert Challenges Industry Orthodoxy: High-Purity Rare Earths Not Required for NdFeB Magnet Production

Highlights

• KU Leuven discovers NdFeB magnets can be manufactured using mixed rare earth elements without costly high-purity separation.
• Current automotive magnet samples already use mixed rare earth blends while maintaining performance specifications.
• This breakthrough could reduce production costs, environmental impact, and challenge China’s rare earth element supply chain dominance.

A possible rare earths breakthrough emerging from KU Leuven’s SOLVOMET Research & Innovation Centre (opens in a new tab) is turning industry assumptions upside down. According to recent findings, high-purity rare earth elements (REEs) are not necessary for the manufacture of Nd-Fe-B (neodymium-iron-boron) permanent magnets — a core component in electric vehicles (EVs), wind turbines, and defense systems.

Dr. Koen Binnemans, (opens in a new tab) a leading authority on hydrometallurgy and REE chemistry, revealed via LinkedIn that NdFeB magnets can be made from mixtures of rare earths, bypassing the need for costly and resource-intensive purification processes. “This could slash costs and environmental impact,” he stated, “while maintaining the magnetic performance required by today’s advanced technologies.”

Currently, separating individual REEs to 99.9%+ purity via solvent extraction demands over 1,000 stages — a painstaking and expensive endeavor. Yet, KU Leuven’s analysis of actual automotive magnet samples, including one from a power steering motor, shows the use of mixed REEs:

• Neodymium: 20.9 wt%
• Praseodymium: 4.2 wt%
• Dysprosium: 3.8 wt%
• Terbium: 0.6 wt%
• Gadolinium: 0.2 wt%

“Notably,” Binnemans adds, “these magnets used non-purified REE blends, and yet performed to spec.”

The implications are profound. Instead of relying on ultra-pure neodymium, manufacturers can use mischmetal (opens in a new tab) — a naturally occurring blend of light REEs — with minimal pre-processing. Only samarium needs to be excluded. Moreover, dysprosium and terbium, essential for high-temperature performance, can be added as a combined alloy, sidestepping the difficult and energy-intensive separation between the two.

This revelation arrives at a pivotal moment. As global supply chains strain under China’s dominance of rare earth separation, a paradigm shift toward tolerance for REE impurity could offer new life to ex-China magnet supply chains.

Rare Earth Exchanges Commentary

Binnemans’ insight challenges the prevailing industrial fixation on chemical purity — a costly hangover from legacy applications like phosphors and lasers. For NdFeB magnets, tolerating mixed REE inputs may unlock new sourcing strategies from low-grade ores, mine tailings, and recycled materials, empowering Western nations to reenter the magnet supply chain on more flexible terms.

This development invites a critical rethink: Are we wasting billions on purifying rare earths beyond what magnets actually need? If so, a cleaner, cheaper, and more geopolitically resilient path lies ahead.