A secondary impact crusher is a type of crusher used after primary crushing in aggregate production processes. It is designed to reduce materials to smaller, cubical sizes (typically 2-5 cm or finer) from the primary crusher’s output (10-15 cm). This crusher is ideal for medium-hard rocks (limestone, basalt, dolomite) and recycled materials (concrete debris, asphalt).

Working Principle:

  • Impact Mechanism: High-speed rotating blow bars or hammers on a rotor transfer kinetic energy to the material, breaking it apart.

  • Impact and Compression: Material is repeatedly struck between the rotor and fixed crushing plates (apron plates), ensuring fragmentation and shaping.

  • Size Control: Adjustable output screens or crushing chamber settings regulate the final product size (e.g., 0-25 mm, 5-15 mm).

Advantages:

  • High Efficiency: Impact crushing breaks materials quickly and energy-efficiently.

  • Cubical Shape: Produces angular, cubical aggregates ideal for concrete and asphalt bonding.

  • Versatility: Effective even with moist or clay-containing materials (especially in dry systems).

  • Adjustable Output: Product size can be customized by changing screens or adjusting rotor speed.

Applications:

  • Concrete and asphalt aggregate production,

  • Road base and railway ballast,

  • Recycling concrete/asphalt debris in recycling plants,

  • Processing limestone or basalt in quarries.

Key Components:

  • Rotor: The rotating core that propels material.

  • Blow Bars: Wear-resistant steel plates attached to the rotor.

  • Apron Plates: Fixed plates lining the crushing chamber.

  • Drive System: Powered by electric or diesel engines.