The iron ore pelletizing process transforms fine iron ore concentrate into uniform pellets (6–18 mm) for blast furnace or direct reduction. Key stages include:
1. Raw Material Preparation: Crushed ore is ground to ≤45 microns using ball mills.
2. Mixing & Binder Addition: Bentonite (0.5–1.5%) and water are blended in mixers to form green pellets.
3. Pellet Formation: Disc or drum pelletizers shape moist particles into spherical pellets.
4. Induration: Pellets are hardened in a grate-kiln (1250–1350°C) or straight-grate system, achieving >2,000 N/pellet strength.
| Equipment | Key Parameters |
|---|---|
| Ball Mill | Capacity: 50–300 t/h; Power: 1,000–6,000 kW |
| Pelletizer | Disc Diameter: 5–8 m; Inclination: 40–50° |
| Grate-Kiln | Productivity: 1–6 Mt/year; Fuel Consumption: 0.9–1.2 GJ/t |
Q: What’s the typical pellet Fe content?
A: 62–67%, with SiO₂ <5%.
Q: How to reduce bentonite usage?
A: Organic binders (e.g., Peridur) can cut bentonite by 50%.
Project: Vale’s Tubarão Plant (Brazil)
Output: 9 Mt/year pellets
Solution: Combined grate-kiln system with recycled heat recovery, reducing energy by 15%.
