Iron ore beneficiation in India involves several stages to upgrade low-grade iron ores into high-grade concentrates suitable for steel production. The flowsheet varies based on the ore type (hematite, magnetite, or goethite) and its characteristics. Below is a generalized iron ore beneficiation flowsheet commonly used in India:
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Typical Iron Ore Beneficiation Flowsheet in India
# 1. Crushing & Screening
– Primary Crushing: Run-of-mine (ROM) ore is crushed using jaw crushers or gyratory crushers.
– Secondary & Tertiary Crushing: Cone crushers reduce the ore to ~10–30 mm.
– Screening: Oversize material is recirculated, while undersize proceeds to grinding.
# 2. Grinding (For Hematite/Magnetite Ores)
– Ball Mill/HPGR (High-Pressure Grinding Rolls): Ore is ground to liberate iron minerals from gangue (typically 75–150 microns).
– Classification: Hydrocyclones separate fine and coarse particles; coarse material is recycled.
# 3. Beneficiation Techniques
## For Hematite Ores (Common in Odisha, Jharkhand, Chhattisgarh)
– Spiral Concentrators: Separate heavy iron oxides from lighter silica.
– Gravity Separation (Jigs, Tables): Used for coarse-to-medium particles.
– Magnetic Separation (LIMS/HIMS): Removes weakly magnetic impurities.
– Flotation (Reverse flotation): Silica/gangue is floated away from iron using reagents.
## For Magnetite Ores
– Low-Intensity Magnetic Separation (LIMS): Captures magnetite particles directly.
– High-Intensity Magnetic Separation (HIMS): Removes hematite/silica from magnetite concentrates.
## For Goethitic/Lateritic Ores
– Washing & Scrubbing: Removes clay and alumina impurities.
– Selective Flocculation: Enhances iron recovery from ultrafine particles.
# 4. Dewatering & Tailings Management
– Thickeners: Concentrate slurry is thickened to reduce water content.
– Filters (Vacuum/Disc Filters): Further dewatering to ~8–12% moisture.
– Tailings Disposal: