A Crushed Stone (Aggregate) Crushing and Screening Plant is an industrial system designed to crush, screen, and classify natural rocks, ores, or construction waste into specific-sized aggregates. These plants produce materials critical for construction while promoting sustainable resource management through recycling.

Purpose and Functions:

  1. Aggregate Production:

    • Crushes natural stones or waste into standardized sizes (0-5 mm, 5-12 mm) for road construction, concrete, and infrastructure projects.

    • For example, 5-12 mm aggregates are used in asphalt, while 20-40 mm aggregates form railway ballast.

  2. Waste Recycling:

    • Processes demolition debris (concrete, bricks) into reusable materials, reducing landfill use and raw material extraction.

  3. Mineral Processing:

    • Reduces raw ores (e.g., gold, copper) to manageable sizes for further refining.

  4. Custom Solutions:

    • Produces specialized aggregates for dam construction or high-strength concrete.

How It Works?

1. Material Feeding and Pre-Treatment:

  • Raw material is loaded into the vibrating feeder via excavator.

  • Optional pre-screening removes fines (soil, clay).

2. Primary Crushing:

  • A Jaw Crusher or Impact Crusher reduces rocks to 100-300 mm chunks.

  • Jaw crushers apply compressive force; impact crushers use high-speed rotors.

3. Secondary/Tertiary Crushing:

  • Cone Crushers or Tertiary Impact Crushers refine the material to 20-50 mm.

  • Vertical Shaft Impactors (VSI) produce sand-sized particles (0-5 mm).

4. Screening Phase:

  • Vibrating Screens sort aggregates using multi-layered decks.

    • Example: A 4-deck screen separates:

      • Layer 1: >40 mm (recirculated).

      • Layer 2: 20-40 mm (road base).

      • Layer 3: 5-20 mm (concrete aggregate).

      • Layer 4: 0-5 mm (sand).

5. Stockpiling and Dispatch:

  • Conveyor belts transport sorted aggregates to designated stockpiles.

  • Stockpiling balances moisture content and streamlines logistics.

Components and Technical Details:

  • Primary Crusher:

    • Jaw crushers handle up to 1,500 tons/hour.

    • Impact crushers suit softer materials like limestone.

  • Cone Crusher:

    • Hydraulic adjustment systems ensure precise output control.

  • Vibrating Screens:

    • Polyurethane or steel mesh screens resist wear.

    • Inclined designs optimize material flow.

  • Mobile Chassis:

    • Tracked models operate on slopes up to 30°.

    • Wheeled units enable highway transport.

Advantages:

  • High Efficiency: Processes 50-800 tons/hour in a single setup.

  • Closed-Circuit Operation: Automatically recirculates oversized material.

  • Energy Savings: Variable Frequency Drives (VFDs) reduce power consumption by 20%.

  • Modular Design: Crushers and screens can be customized for specific projects.

Industrial Applications:

  • Highway Construction: 20-40 mm aggregates for base layers.

  • Precast Concrete: 5-12 mm aggregates enhance structural strength.

  • Railway Ballast: 25-50 mm aggregates dampen vibrations under tracks.

  • Airport Runways: 0-5 mm sand binds asphalt mixtures.