Application of Raymond Mill in NdFeB Powder Preparation for NdFeB Waste Recycling Technology

Introduction

The rapid growth of the NdFeB (Neodymium Iron Boron) magnet industry has led to a significant increase in manufacturing waste and end-of-life products. Recycling this waste is crucial for resource conservation and environmental protection. A critical step in the recycling process is the preparation of fine NdFeB powder from solid waste, where grinding technology plays a pivotal role. Raymond Mill technology, specifically designed for fine and ultrafine grinding, offers an efficient and reliable solution for this application.

The Importance of NdFeB Waste Recycling

NdFeB magnets contain valuable and critical rare earth elements (REEs) such as Neodymium (Nd), Praseodymium (Pr), and Dysprosium (Dy). Recycling helps mitigate the environmental impact of mining, reduces supply chain dependencies, and supports a circular economy. The recycling process typically involves: dismantling, pre-processing, coarse crushing, fine grinding to powder, and subsequent hydrometallurgical or pyrometallurgical steps to recover the REEs. The quality of the prepared powder, particularly its fineness and particle size distribution (PSD), directly influences the efficiency of the subsequent metal recovery processes.

Challenges in NdFeB Powder Preparation

Grinding NdFeB material presents unique challenges. The material is extremely hard and brittle. The goal is to achieve a very fine and consistent powder (often requiring a D97 of less than 10μm) without causing oxidation or introducing metallic impurities from the milling equipment itself. Furthermore, the process must be energy-efficient and environmentally clean to make the recycling operation economically viable.

Piles of NdFeB manufacturing scrap and end-of-life magnets ready for recycling

Why Raymond Mill Technology is Ideal

Traditional grinding systems like ball mills can be inefficient and prone to contamination. Modern Raymond Mill systems, particularly ultrafine versions, overcome these limitations. Their working principle involves grinding rollers applying centrifugal force to crush materials against a stationary grinding ring. The crushed powder is then classified by an integrated air classifier, ensuring only particles of the desired fineness proceed to the collection system. This closed-loop system is ideal for NdFeB as it minimizes oxidation risk and allows for precise control over the final product’s PSD.

Key Technical Requirements for the Grinding Mill

For effective NdFeB powder preparation, the milling equipment must meet several key criteria:

  • High Precision Classification: Ability to achieve a tight and consistent particle size cut-point (D97 ≤ 5μm).
  • Wear Resistance: Critical grinding components must be made from special wear-resistant materials to prevent iron contamination and ensure long service life.
  • Energy Efficiency: The process must consume minimal energy per ton of processed powder.
  • Environmental Control: A fully sealed system with efficient pulse dust collection is mandatory to contain fine, valuable powders and meet environmental standards.
  • Process Control: Intelligent systems to automatically monitor and adjust for consistent product quality.

Recommended Solution: SCM Ultrafine Mill

For the most demanding NdFeB recycling applications requiring the finest powders, our SCM Ultrafine Mill is the premier choice. This mill is engineered to excel in precisely the areas critical for NdFeB processing.

Its core parameters align perfectly with the task: an input size of ≤20mm and the ability to produce powder with a fineness ranging from 325 to 2500 mesh (D97 ≤ 5μm), with a throughput of 0.5 to 25 tons per hour depending on the model selected.

The technical advantages of the SCM Ultrafine Mill are particularly relevant:

  • Efficient & Energy-Saving: It offers twice the capacity of jet mills while reducing energy consumption by 30%. Its intelligent control system provides automatic feedback on product fineness.
  • High-Precision Classification: A vertical turbine classifier ensures precise particle size cuts, guaranteeing a uniform product without coarse particle contamination.
  • Durable Design: Special material rollers and grinding rings extend service life significantly. The innovative bearingless screw in the grinding chamber ensures stable operation.
  • Environmental & Low Noise: The pulse dust collector exceeds international efficiency standards, and the soundproof room design keeps noise levels below 75dB.

SCM Series Ultrafine Mill installed in an industrial setting for mineral processing

Alternative Solution: MTW Series Trapezium Mill

For operations where the target powder fineness is slightly less stringent (30-325 mesh), our MTW Series Trapezium Mill presents a robust and high-capacity alternative. It is capable of handling input sizes up to 50mm with a impressive throughput ranging from 3 to 45 tons per hour.

This mill features several advanced design elements, including anti-wear shovel blades, an optimized curved air duct to reduce energy loss, and an efficient cone gear overall transmission system with 98% transmission efficiency. Its sturdy construction and high capacity make it suitable for larger-scale recycling operations focused on initial size reduction steps.

Integration into a Complete Recycling Line

The Raymond Mill is the heart of the size reduction section in an NdFeB recycling plant. A typical flow would involve:

  1. Initial coarse crushing of bulk waste using a Jaw Crusher or Hammer Mill.
  2. Magnetic separation to remove non-magnetic impurities.
  3. Fine grinding using the SCM Ultrafine Mill to achieve the target powder fineness.
  4. Powder collection via a cyclone and pulse bag filter system.
  5. Further processing of the fine powder for rare earth extraction.

The mill’s intelligent control system allows for seamless integration and automated operation within this larger process flow.

Process flow diagram showing the integration of a grinding mill into a complete NdFeB recycling system

Conclusion

The application of advanced Raymond Mill technology is a cornerstone of modern and efficient NdFeB waste recycling. The ability to produce a consistent, ultra-fine, and contamination-free powder is essential for maximizing the recovery yield of valuable rare earth elements. Our SCM Ultrafine Mill, with its exceptional precision, durability, and energy efficiency, is specifically engineered to meet the stringent demands of this critical application, providing recyclers with a reliable and economical solution to contribute to a more sustainable magnet industry.

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