Comminution_of_Minerals_with_Grinding.pptx

grinding and comminution

1. Comminution of Minerals Based on Wills' Introduction to Mineral Processing Presented by: [Your Name]

2. Introduction to Comminution What is Comminution? • Comminution is the process of reducing the size of minerals to liberate valuable components. • Involves crushing and grinding to achieve the desired particle size. • Essential for efficient mineral separation in subsequent processes (e.g., flotation, gravity separation).

3. Importance of Comminution Why is Comminution Important? • Liberation of valuable minerals from gangue materials. • Prepares the ore for subsequent processing (beneficiation). • Influences the efficiency of separation processes like flotation and leaching. • Reduces energy consumption by optimizing particle size.

4. Stages of Comminution Crushing • Initial stage of size reduction. • Typically uses jaw crushers, gyratory crushers, and cone crushers. • Reduces large ore chunks to sizes suitable for grinding. Grinding • Second stage, where particles are further reduced. • Ball mills, rod mills, and autogenous mills are common. • Produces fine particles necessary for mineral liberation.

5. Crushing – Types of Crushers Types of Crushers: • Jaw Crusher: Primary crusher for large ore pieces. • Gyratory Crusher: High throughput, coarse crushing. • Cone Crusher: Secondary crusher, produces finer particles.

6. Grinding – Types of Mills • Ball Mill: Uses steel balls to grind ore into fine particles. • Rod Mill: Uses rods; produces coarser particles than ball mills. • Autogenous (AG) & Semi-Autogenous (SAG) Mills: Use ore itself as grinding medium. • Stirred Mills: More energy-efficient, used for ultra-fine grinding.

7. Energy Considerations in Comminution Energy Efficiency: • Comminution consumes up to 50% of a plant’s energy. Strategies for Efficiency: - Optimize mill performance and use advanced control systems. - Reduce over-grinding to lower energy wastage.

8. Factors Affecting Comminution Efficiency • Ore Characteristics: Hardness, grain size. • Equipment Choice: Depends on ore type, product size. • Operating Conditions: Speed, feed rate, load influence efficiency.

9. Comminution Circuits • Open-Circuit: Ore passes through crushers/mills once. • Closed-Circuit: Recirculates material for further size reduction.