Laser-Induced Innovation: Quantitative Dysprosium Analysis in NdFeB Magnets for Recycling

Highlights

• French researchers develop laser spectroscopy method to accurately quantify dysprosium in rare earth magnets for improved recycling processes.
• Study demonstrates LIBS technology can measure dysprosium content through protective coatings and oxidation layers, enhancing industrial recycling workflows.
• Research aims to reduce global dependency on rare earth element supplies by creating more efficient recycling techniques for critical materials.

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A new study by Jean-Baptiste Sirven and collaborators affiliated with Université Paris-Saclay and Université Grenoble Alpes, both in France, introduces the MAGNets on pilOt LIne Ambition (MAGNOLIA) project, exploring a groundbreaking method to support the recycling of rare earth element-rich magnets.

Conducted under the leadership of Bpifrance, this research tackles the growing demand for recycling NdFeB magnets containing dysprosium (Dy), a critical component in electric vehicles and wind energy systems. The study’s hypothesis was clear: laser-induced breakdown spectroscopy (LIBS) can effectively quantify dysprosium in magnets, even when coated or oxidized, making it viable for industrial recycling processes.

Study Design

The researchers used two Laser Induced Breakdown Spectroscopy (LIBS) systems to test their hypothesis. The first, a commercial short-range device, optimized laser ablation to measure dysprosium content at depths of 35–60 micrometers with a relative uncertainty of less than 10%. The second system, a custom long-range setup, aimed to enable measurements over a conveyor belt. While initial results showed low ablation efficiency, a switch to a free-running laser mode significantly improved performance.

Key Findings

The study confirmed that LIBS could provide accurate, rapid dysprosium analysis, even under protective coatings or oxidation layers, a major challenge in recycling workflows. The short-range system demonstrated a reliable calibration method for dysprosium quantification. The long-range system, though less mature, showed promise for future online implementation in industrial settings.

Limitations

This pioneering study has limitations. The long-range LIBS system requires further optimization for consistent industrial use. The research also focused solely on dysprosium, leaving other critical elements in NdFeB magnets unaddressed—additionally, the impact of diverse coatings and operational conditions on accuracy warrants further exploration.

Implications

The study highlights the potential of LIBS technology to revolutionize recycling processes for rare earth elements, reducing dependency on China’s monopoly over REE supplies.

This method could improve the economic and environmental efficiency of recycling workflows by enabling real-time, online sorting of magnets. Future advancements in LIBS could expand its applicability to other elements and industrial contexts, further supporting sustainable technologies.

This research underscores the need for innovative solutions to resource challenges, aligning with global efforts to secure critical materials for renewable energy and green technologies.