Lesson 5: Concentration of Ores
This lesson focuses on the various techniques used to concentrate ores. The choice of method depends on the physical and chemical properties of the ore and the gangue.
- Hydraulic Washing: This method, also known as gravity separation, is used for heavy ores. The ore is washed with a stream of water, which carries away the lighter gangue particles.
- Magnetic Separation: This method is used for ferromagnetic ores like hematite. The crushed ore is passed over a magnetic roller, which separates the magnetic ore from the non-magnetic gangue.
- Froth Flotation Process: This technique is used for sulfide ores. The finely powdered ore is mixed with water and pine oil. Air is blown into the mixture, creating a froth that carries the sulfide ore particles to the surface, while the gangue settles at the bottom.
- Leaching: This is a chemical method where the ore is treated with a suitable chemical reagent that dissolves the ore but not the gangue. It’s used for extracting metals like silver and gold.
