NdFeB Magnet Scrap Recycling: How Vertical Roller Mills Process and Recover Rare Earth Materials

Introduction to NdFeB Magnet Scrap Recycling

The recycling of NdFeB (Neodymium-Iron-Boron) magnet scrap is critical for recovering valuable rare earth elements (REEs) like neodymium, praseodymium, and dysprosium. These materials are essential for modern technologies, including electric vehicles, wind turbines, and electronics. Vertical roller mills (VRMs) play a pivotal role in processing magnet scrap into fine powders, enabling efficient separation and recovery of REEs through subsequent hydrometallurgical or pyrometallurgical methods.

Challenges in NdFeB Scrap Processing

NdFeB magnets are hard and brittle, making size reduction challenging. Traditional crushing methods often lead to excessive heat generation, oxidation, and loss of rare earth materials. Additionally, achieving uniform fine grinding is crucial for maximizing surface area in leaching processes. VRMs address these issues with precision grinding, controlled particle size distribution, and minimal thermal degradation.

How Vertical Roller Mills Work in Rare Earth Recovery

Vertical roller mills utilize a bed compression grinding mechanism, where material is fed between rotating grinding rollers and a stationary grinding table. The scrap is crushed and ground by pressure and shear forces, producing fine powders with consistent particle size. Key stages include:

• Pre-Crushing: Magnet scrap is initially reduced to ≤20mm pieces using crushers like hammer mills.
• Grinding: The pre-crushed material is fed into the VRM, where rollers exert high pressure to pulverize it into fine powder.
• Classification: Integrated dynamic classifiers separate particles by size, ensuring optimal fineness for leaching.
• Collection: Fine powder is collected via cyclones and bag filters, while coarse material is recycled for further grinding.

This process minimizes energy consumption and heat generation, preserving the chemical integrity of rare earth elements.

Recommended Product: SCM Ultrafine Mill

For high-precision grinding of NdFeB scrap, our SCM Ultrafine Mill is ideal. It achieves fineness up to 2500 mesh (D97 ≤5μm), ensuring maximum surface area for efficient leaching. With capacities from 0.5 to 25 ton/h and energy savings of 30% compared to jet mills, it features a vertical turbine classifier for precise particle size control and durable grinding components for long service life. The mill operates at low noise levels (≤75dB) and includes pulse dust collection for environmental compliance.

Advantages of VRMs in Rare Earth Recycling

• Energy Efficiency: VRMs consume 30-50% less energy than ball mills, reducing operational costs.
• Precision Grinding: Adjustable parameters allow control over particle size, enhancing leaching efficiency.
• Low Contamination: Ceramic or hardened steel grinding components prevent iron contamination.
• Scalability: From pilot-scale to industrial production, VRMs like the LM Series Vertical Roller Mill offer capacities up to 250 ton/h, integrating grinding, drying, and classification in a single unit.

Case Study: Integrating SCM Mill into Recycling Workflow

In a typical NdFeB recycling plant, scrap magnets are first demagnetized and decoated. The material is then pre-crushed to ≤20mm and fed into an SCM Ultrafine Mill. The output, with D97 ≤5μm, is leached in acid solutions to dissolve REEs, followed by solvent extraction and precipitation. The mill’s high throughput and fine output increase recovery rates by over 20% compared to conventional grinding.

Environmental and Economic Benefits

Using VRMs for NdFeB recycling reduces the environmental footprint of mining new rare earths. It also lowers costs, as recycled REEs are 30-50% cheaper than virgin materials. Our MTW Series Trapezium Mill is another excellent option, handling inputs up to 50mm with outputs from 30-325 mesh. Its curved air duct and wear-resistant components ensure efficient, low-maintenance operation for large-scale recycling projects.

Conclusion

Vertical roller mills are indispensable in NdFeB magnet scrap recycling, offering efficient, precise, and eco-friendly grinding. Our SCM Ultrafine Mill and MTW Series Trapezium Mill provide robust solutions for recovering rare earth materials, supporting sustainable technology and circular economy goals. For more details, explore our product specifications and technical support services.