How to Maintain Optimal Grinding Speed for Different Graphite Types

Optimal grinding speed depends mainly on graphite hardness, crystallinity, flake integrity, target fineness, and temperature control. Too high speed causes over-grinding, overheating, or flake damage; too low reduces efficiency.

1. Natural Flake Graphite

This type has a layered structure and high value in flake shape — avoid breaking flakes.

• Grinding speed: Medium–low main shaft speed
• Classifier speed: Medium (to retain flake size)
• Rules:
  • Reduce speed by 10–15% if flakes are severely broken
  • Keep grinding temperature below 60°C to prevent oxidation
  • Do not run at maximum speed; stable medium speed gives best yield

2. Amorphous / Microcrystalline Graphite

Softer, easier to grind, lower purity, more abrasive.

• Grinding speed: Medium–high speed
• Classifier speed: Slightly higher for fine powder
• Rules:
  • Can increase speed appropriately to improve output
  • Watch motor load; avoid overload from high feeding
  • Regularly check lining wear due to abrasiveness

3. Synthetic Graphite

High purity, uniform structure, moderate hardness.

• Grinding speed: Stable medium speed
• Classifier speed: Adjustable according to fineness
• Rules:
  • Fine grade → slightly lower grinding speed + higher classifier speed
  • Coarse grade → slightly higher grinding speed
  • Maintain steady speed to avoid particle size fluctuation

4. Spherical Graphite (Battery Grade)

Requires precise shape and narrow particle distribution.

• Grinding speed: Low & stable speed
• Classifier speed: High precision control
• Rules:
  • No high-speed impact grinding
  • Use gentle grinding mode; avoid over-reduction
  • Strict temperature control (≤50°C)

5. Key General Rules for All Graphite Types

1. Temperature control

• Graphite oxidizes at high temperature. If mill temperature rises sharply, reduce speed immediately and strengthen ventilation/cooling.
• Fineness adjustment
  • Coarser powder: slightly higher grinding speed
  • Finer powder: lower grinding speed + higher classifier speed
• Stable feeding
• Uneven feeding causes speed fluctuation. Maintain constant feed rate to keep optimal speed.
• Equipment condition
  • Check belt tension, bearing clearance, and motor performance regularly
  • Worn liners or grinding rollers will reduce actual grinding efficiency — replace in time to avoid needing excessively high speed
• Avoid resonance
  1. Do not run at critical vibration speed, which causes instability and poor grinding.
• Flake graphite: Low–medium speed, protect flakes
• Amorphous graphite: Medium–high speed, improve efficiency
• Synthetic graphite: Medium speed, stable particle size
• Spherical graphite: Low speed, precise control

Always adjust speed based on real-time temperature, particle size, and motor load to keep optimal grinding performance.