An overview of the principles, objectives, and importance of mineral processing in extracting valuable minerals from ores.
Introduction to Mineral Processing
Also called ore beneficiation, mineral dressing, or simply “processing”
| Aspect | Reason |
|---|---|
| Economic | Increases the amount of metal that can be sold from a given ore body. |
| Resource Efficiency | Allows lower‑grade deposits to become viable. |
| Environmental | Reduces waste volume, energy use, and tailings toxicity when optimized. |
| Regulatory | Meets legal limits on tailings, water discharge, and emissions. |
Typical flow diagram
Mine → Crushing → Grinding → Classification → Concentration → Dewatering → Product
↓
Tailings → Management
| Operation | Principle | Typical Use |
|---|---|---|
| Crushing | Apply compressive force to break rocks. | Reduces run‑of‑mine (ROM) ore to < 200 mm. |
| Grinding | Impact, attrition, or abrasion to produce fine particles. | Ball mills, SAG mills, HPGR – target 10–150 µm for most ores. |
| Screening | Mechanical sieving to separate by size. | Primary/secondary screens for coarse fractions. |
| Hydro‑cyclones | Centrifugal forces separate particles by density & size. | Fine grinding classification (10–150 µm). |
| Gravity Separation | Exploits density differences (e.g., jig, shaking table, spirals). | Precious metals, heavy minerals, coarse sulfides. |
| Magnetic Separation | Uses magnetic susceptibility. | Magnetite, ilmenite, iron‑bearing gangue. |
| Flotation | Surface chemistry: reagents make target mineral hydrophobic, bubbles carry it to the surface. | Base‑metal sulfides, many non‑ferrous ores. |
| Leaching | Dissolves target mineral in a solvent (e.g., cyanide, acid). | Gold, copper, uranium, rare earths. |
| Thickening | Settles solids to a higher concentration. | Tailings and concentrate handling. |
| Filtration | Removes water from solids via pressure or vacuum. | Final concentrate drying. |
| Term | Meaning |
|---|---|
| Feed | Material entering a unit operation. |
| Product (Concentrate) | Material enriched in valuable mineral. |
| Tailings | Residual waste after extraction. |
| Recovery | % of the valuable mineral in the feed that ends up in the product. |
| Grade | Concentration |