With the increasing demands for rate performance and cycle life of high-performance lithium-ion batteries—particularly for artificial graphite—the core raw material, Needle Coke, must meet extremely stringent requirements for compressive strength and particle size distribution (PSD). Located in Ningbo, a major hub for China’s lithium battery industry, a renowned anode material manufacturer required an ultra-fine grinding system capable of processing hard, fibrous needle coke to a stable fineness of D97 ≤ 3μm for their specialized fine-particle product line.
1. Core Challenges
- Extremely Narrow PSD: The client required D97 to be strictly controlled between 2–3μm, posing a massive challenge to the classifier’s precision and flow field stability.
- Morphology Preservation: While achieving ultra-fine reduction, the system must minimize over-grinding to maintain the inherent crystalline structure of the needle coke.
- Contamination Control: Anode materials have zero tolerance for metallic impurities (such as Fe, Cu, Zn), requiring rigorous magnetic matter control.
2. Solution: Epic Powder MQW Series Jet Mill System for Needle Coke Ultra-fine Grinding
To address these requirements, the production line integrated the Epic Powder MQW Series Jet Mill. This system utilizes supersonic airflow to drive material-to-material collisions, effectively solving both wear and purity concerns.
Key Technical Configurations:
- Vertical High-Precision Classification: Equipped with a high-speed, high-strength grading rotor to ensure precise “cutting” of particles below 3μm.
- Full Ceramic Lining: All contact parts are lined with Alumina or Silicon Carbide ceramics, ensuring that metallic pick-up remains near zero.
- Constant Air-to-Solid Ratio: An automated feeding system maintains a stable material concentration within the grinding chamber, ensuring consistent particle size output.
3. Operational Data and Results
Following onsite commissioning and continuous production, the MQW Jet Mill demonstrated exceptional process stability, with all indicators exceeding client expectations.
Production Performance Table
| Item | Requirement | Actual Result |
| Material | Needle Coke (Calcined) | Needle Coke |
| Finished Fineness (D97) | 2–3 μm | 2.94 μm |
| Capacity | 50 kg/h | 52 kg/h |
| Particle Size (D50) | Monitoring Item | ≈1.8 μm |
| Magnetic Matter Increase | ≤10 ppb | Compliant |