A tertiary impact crusher is a machine used in the tertiary crushing stage to reduce materials from secondary crushers into ultra-fine sizes (0-25 mm). Designed for high cubicity and sand production, it is ideal for soft to medium-hard materials (limestone, basalt, concrete, asphalt, marble, etc.). Tertiary crushers maximize aggregate quality and meet the demand for fine materials in specialized applications.

2. Purpose

  • Fine Crushing: Reduces secondary-crushed material (5-50 mm) to sand or powder sizes (0-25 mm).

  • Cubical Sand Production: Creates angular, uniform aggregates ideal for concrete and asphalt.

  • Size Homogeneity: Controls particle size distribution for consistent quality.

  • Recycling: Converts waste materials (concrete, bricks, glass) into high-quality fine aggregates.

3. How Does It Work?

A. Key Components

  • Rotor: A high-speed (1000-1500 rpm) rotor with hammers (blow bars) or paddles delivers intense impact force.

  • Adjustable Impact Plates: Hydraulic or mechanical plates control the crushing angle and output size.

  • Grinding Chamber: The impact zone between the rotor and plates ensures repeated collisions for fine grinding.

  • Vibrating Screen/Grate: A specialized screen prevents clogging and regulates final particle size.

  • Closed-Circuit System: Oversized particles automatically recirculate for re-crushing.

B. Operational Stages

  1. Feeding: Material from secondary crushers or screens enters the tertiary crusher’s hopper.

  2. High-Speed Impact: Rotor hammers propel material against the impact plates at high velocity.

  3. Crushing & Grinding: Micro-impacts fracture the material, while rotor direction and plate angle optimize cubical shaping.

  4. Screening & Recirculation: Crushed material passes through the screen; oversized particles return to the chamber.

  5. Discharge: Fine aggregates or sand are transported to storage or packaging units.

4. Advantages

  • High Cubicity: Up to 90% cubical grains enhance concrete strength.

  • Adjustable Output: Real-time adjustments via hydraulic systems for plate gap and rotor speed.

  • Low Wear Costs: Alloy hammers and rubber-lined plates extend service life.

  • Dust Control: Enclosed design and filters minimize environmental impact.

5. Applications

  • Sand Quarries: Producing cubical sand as a natural sand alternative.

  • Concrete Plants: Preparing fine aggregates for high-strength concrete.

  • Asphalt Plants: Manufacturing specialized mixes like SMA (Stone Mastic Asphalt).

  • Mines: Pulverizing ores (e.g., gold processing).