From industrial spheroidization‑anode production practice referenced from graphite‑mill.com technical data, ‑100 mesh (150 μm opening) is the mainstream initial sieving mesh for incoming flotation‑concentrate natural flake graphite before grinding‑shaping and spheroidization.
Detailed explanation
- Primary initial sieve after flotation concentrate drying (pretreatment stage)
- Standard mesh: ‑100 mesh (150 μm aperture); remove +100 mesh oversize large flakes, rock gangue and foreign impurities before feeding into grinding‑shaping equipment.
- Alternative industrial options: Some production lines adopt ‑80 mesh (180 μm) for coarse‑flake‑rich raw ore; for finer flake sources, ‑120 mesh can be selected as initial sieve cutoff.
- Purpose of initial sieving: Eliminate oversized interlocked gangue‑graphite composite particles, protect rotor and lining of downstream shaping/spheroidization mill, reduce impurity liberation load for subsequent processes.
Feed after initial screening: D50 approx. 70‑110 μm, fixed carbon 94‑96 %, moisture controlled ≤0.5 % before grinding‑shaping.
- Not to confuse with intermediate‑process mesh
- ‑200 mesh / ‑325 mesh are intermediate‑grading mesh after grinding‑shaping, not initial raw‑material sieving mesh. Those meshes are deployed after particle‑size reduction, ahead of spheroidization or magnetic‑separation station.
- Initial sieving is a coarse safety‑gate screening step for flotation concentrate; it does not reach final anode fineness.
- Practical production notes
- Initial sieving usually uses ultrasonic vibrating screen to prevent sheet‑shaped graphite mesh‑clogging.
- Any +100 mesh oversized fraction from initial sieve will return to coarse grinding loop for re‑liberation, rather than directly discarded.
- If raw ore carries abundant extra‑large flakes, pre‑coarse scalping with 20‑40 mesh can be arranged ahead of the formal‑100 mesh initial sieve to remove bulk rock debris.
Quick reference table
| Stage | Mesh | Opening | Function |
|---|---|---|---|
| Pre‑scalping (optional) | 20‑40 mesh | 425‑850 μm | Remove bulk rock debris |
| Initial raw‑material sieving (main) | ‑100 mesh | 150 μm | Cut oversize for spheroidization feedstock |
| Intermediate screening after grinding‑shaping | ‑200 mesh | 75 μm | Intermediate size grading |
| Fine screening post‑spheroidization | ‑325 mesh | 45 μm | Remove oversize for spherical graphite finished product |
