Highlights

• Chinese researchers developed a method to recycle NdFeB magnet waste into high-performance magnets using 95 wt% recycled material, achieving 95.9% remanence recovery and 99.6% coercivity recovery through active grain boundary reconstruction.
• The innovation uses grain boundary engineering to transform machining sludge—about 35% of magnet production waste—into commercial-grade magnets, potentially reducing reliance on primary rare earth mining for electric vehicles, wind turbines, and defense systems.
• While laboratory results are compelling, the 2026 preprint study requires peer review and faces questions about industrial scalability, economic viability versus primary production, and dependence on heavy rare earth inputs like terbium.

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In a 2026 preprint (opens in a new tab) led by Pengwei Li, Qingmei Lu, and Ming Yue of Beijing University of Technology (opens in a new tab), with collaborators from Hefei Iron & Steel Research Institute and industrial partners, researchers report a novel method to recycle NdFeB magnet waste into high-performance magnets using approximately 95 wt% recycled material. The team introduces an “active grain boundary reconstruction” approach that restores magnetic performance to near-original levels while reducing dependence on newly mined rare-earth materials. If validated beyond the laboratory, the work could reshape the economics of rare earth supply—particularly for magnets essential to electric vehicles, wind turbines, and defense systems.

How the Study Works

The researchers targeted NdFeB machining sludge, a byproduct that can account for roughly 35% of magnet production mass and contains valuable rare earth elements. Conventional recycling typically relies on hydrometallurgical or pyrometallurgical processes—effective, but energy-intensive and environmentally burdensome.

Instead, the team pursued a more direct regeneration pathway:

• Deep purification and oxygen reduction using calcium-based processing
• Conversion into low-oxygen, quasi-spherical magnetic powder
• Surface modification with rare earth hydrides (NdHx, TbHx)
• Controlled sintering to reconstruct the magnet’s internal microstructure

The central innovation lies in grain boundary engineering—rebuilding the microscopic interfaces between magnetic grains that determine performance.

What They Found

The regenerated magnets achieved near-original performance:

• ~95 wt% recycled input material
• ~95.9% remanence recovery
• ~99.6% coercivity recovery
• ~91.9%energy density recovery
• Slightly improved temperature stability versus the original magnet

In practical terms, the recycled magnets approach commercial-grade performance.

Mechanistically, the process works by:

• Replenishing lost rare earth elements via hydride coatings
• Reconstructing a continuous grain boundary phase
• Transforming residual oxides—typically harmful—into magnetic isolation features that enhance coercivity

This is not merely recycling—it is microstructural remanufacturing.

Why This Matters

If scalable, the implications are significant.

Rare earth magnets are foundational to electrification, robotics, and advanced defense systems.

Yet today, recycling contributes only a negligible share of supply. A viablehigh-performance recycling pathway could:

• Reduce reliance on primary mining
• Extend the usable life of rare earth resources
• Strengthen supply chain resilience

However, the geopolitical context is unavoidable. This innovation emerges from China’s tightly integrated rare earth ecosystem—reinforcing its strategic push to control not just extraction, but processing, application, and now recycling.

Limitations and Open Questions

Caution is warranted.

• The study is a preprint and not yet peer-reviewed
• Industrial scalability remains unproven
• The process still depends on heavy rare earth inputs (e.g., terbium)
• Economic viability versus primary production is unclear
• Feedstock variability could limit consistency at scale

In short, the science is compelling—but the industrial case remains open.

REEx Bottom Line

This study outlines what could be a credible pathway toward a circular rare-earth magnet economy, where waste becomes a primary feedstock rather than a liability.

But as history in this sector repeatedly shows, the distance between laboratory success and industrial dominance is measured not in papers, but in throughput, cost, and repeatability—and in many years.

The question now is not whether near-complete recycling is possible.

It is whether it can be done reliably, profitably, and at scale.

Profiles

Organization	Summary	Authors
What is Beijing University of Technology, College of Materials Science and Engineering, Key Laboratory of Advanced Functional Materials, Ministry of Education of China	The Key Laboratory of Advanced Functional Materials at Beijing University of Technology (BJUT), designated by China’s Ministry of Education, is a leading research hub focused on advanced materials science and industrial applications. Embedded within BJUT’s College of Materials Science and Engineering, the lab operates as a multidisciplinary platform specializing in functional materials, materials processing, solid-state physics, and nanotechnology. It supports both fundamental research and applied innovation, with capabilities spanning metallic systems, nano-carbon materials, and advanced manufacturing techniques. As part of a “Double First-Class” university, the laboratory plays a strategic role in China’s materials ecosystem—combining academic research, industry collaboration, and international partnerships—while leveraging advanced infrastructure for material preparation, characterization, and performance optimization.	Pengwei LiQingmei LuXiaoyun Shang  Weiqiang LiuMing Yue
Hefei Iron & Steel Research Rare Earth Permanent Magnet Materials Institute Co., Ltd	Hefei Steel Research Rare Earth Permanent Magnet Materials Research Institute Co., Ltd. is a specialized Chinese research entity linked to the China Iron & Steel Research Institute Group (CISRI). It focuses on the development, testing, and commercialization of advanced rare-earth permanent magnet materials, key for high-performance applications.	Lin Liu
Earth-Panda Advanced Magnetic Materials Co., Ltd.	Earth-Panda Advanced Magnetic Material Co., Ltd. (founded 2003) is a Chinese high-tech enterprise based in Hefei, specializing in the R&D, production, and sales of high-performance sintered NdFeB (Neodymium) and samarium cobalt magnets. As an authorized Hitachi patent user, the firm supplies industries like automotive (EPS rotors), wind power, and electronics, exporting to over 20 countries.	Youhao LiuXiaofei Yi
State Key Laboratory of Rare Earth Permanent Magnetic Materials	The State Key Laboratory of Rare Earth Permanent Magnet Materials (associated with Earth Panda) is a prominent Chinese research facility focused on the development, production technology, and application of rare earth permanent magnets. It operates as a national-level platform for research into advanced magnetic materials, focusing on strategic industries such as new energy vehicles, clean energy, and information technology.	Qingmei LuLin LiuWeiqiang LiuYouhao LiuXiaofei Yi

Citation: Lu Q., Yue M. et al., Achieving Near-complete Recycling of Nd-Fe-B Sludge into High-Performance Magnets via Active Grain Boundary Reconstruction, Beijing University of Technology et al., 2026 (preprint).