Graphite Beneficiation Process: Graded Purification, Safeguarding the Core Value of Flakes

The key to graphite beneficiation lies in balancing purification efficiency with flake preservation. Tailored processing schemes must be developed based on flake size and crystal type to maximise industrial value retention.

For large-flake graphite, beneficiation focuses on ‘graded grinding and flotation’ alongside flake protection. Appropriate grinding media (e.g., rod mills) control particle size to minimise damage to large flakes from gangue minerals. Subsequently, a ‘roughing – multiple regrinding – multiple scavenging’ sequence progressively increases fixed carbon content in concentrates while maximising large flake retention, thereby securing market value.

Fine-flake graphite processing requires enhanced mineral liberation and recovery rates. Optimising grinding intensity enhances abrasion efficiency during coarse grinding. Appropriately extending the flotation process, rationally adjusting flotation reagents (such as composite collectors and emulsified kerosene), and employing intermediate product consolidation followed by regrinding and re-selection—where different intermediate products are returned to corresponding stages based on their properties—effectively boosts fine flake graphite recovery rates and concentrate grades.

Cryptocrystalline graphite, being tightly intergrown with gangue minerals, presents significant liberation challenges. This necessitates the use of high-efficiency fine grinding equipment (such as high-efficiency agitating mills or planetary mills) to achieve deep grinding, enabling thorough individual liberation of graphite from gangue. Subsequent processing follows a closed-circuit flow of ‘rough selection – multiple regrinding – multiple fine selection’ to progressively remove impurities, substantially increasing the fixed carbon content and recovery rate of the concentrate, thereby overcoming the challenges of processing cryptocrystalline graphite.