Several separation techniques are employed to remove gangue from ore:
1. Gravity Separation: Based on differences in density, heavier ore particles settle, while lighter gangue is washed away.
2. Magnetic Separation: Utilizes the varying magnetic properties of ore and gangue; magnetic ore is separated from non-magnetic gangue.
3. Froth Flotation: Relies on differences in hydrophobicity; air bubbles selectively adhere to the surface of valuable minerals, separating them from gangue.
4. Leaching: Involves dissolving the valuable component with a solvent, leaving gangue behind.
5. Electrostatic Separation: Relies on different electrical conductivity of ore and gangue for separation.
These techniques help concentrate valuable minerals for efficient metal extraction.