The Comprehensive Guide to Crushing and Sand-Making in the Aggregate Industry

Industry Background

The global construction boom and infrastructure development have driven unprecedented demand for high-quality sand and aggregates. Natural sand reserves are dwindling due to environmental regulations, making manufactured sand (M-sand) a sustainable alternative. Crushing and sand-making equipment plays a pivotal role in producing precise, gradation-controlled aggregates for concrete, asphalt, and railway ballast.

Core of Crushing & Sand-Making

1. Raw Material Selection
– Ideal materials include granite, basalt, limestone, and river pebbles. Hardness, abrasiveness, and moisture content influence equipment choice.
– Pre-screening removes impurities (e.g., soil, clay) to enhance downstream efficiency.

2. Crushing Process
– Primary Crushing: Jaw crushers or gyratory crushers reduce large rocks (≤1,500mm) to ~200mm.
– Secondary Crushing: Cone crushers or impact crushers further process material to ≤50mm.
– Tertiary Crushing: Vertical shaft impactors (VSIs) or fine cone crushers produce ≤20mm aggregates.

3. Sand-Making Technology
– Dry Process: VSIs with air classifiers yield low-moisture M-sand (ideal for ready-mix concrete).
– Wet Process: Sand washers remove excess fines (<75μm) but consume more water.
– Modular Plants: Compact designs (e.g., mobile crushers + screens) suit remote sites.

4. Screening & Gradation Control
– Multi-deck vibrating screens separate aggregates into 0–5mm (sand), 5–20mm, and 20–40mm fractions.
– Particle shape optimization (cubical vs. flaky) improves concrete strength.

Market Trends & Applications

• Urbanization: High-rise buildings require M-sand with consistent fineness modulus (FM 2.6–3.0).
• Green Quarries: Electric/hybrid crushers reduce carbon footprint (e.g., LT120e).
• Specialty Aggregates: Railway ballast demands tough, angular particles (produced via cone crushers).

FAQ Section

Q1: How to minimize dust in dry sand-making?
A: Install bag filters or mist sprays; opt for closed-circuit VSIs with airflow circulation.



Q2: What’s the lifespan of crusher wear parts?
A: Mn18Cr2 jaw plates last ~200,000 tons in granite crushing; monitor via IoT-based wear sensors.



Q3: Can recycled concrete be used for sand-making?
A: Yes, but pre-remove rebar with magnetic separators and adjust crusher settings for softer material.

Engineering Case Study

Project: 500 TPH Limestone M-sand Plant (Southeast Asia)

• Configuration:

– Primary: CJ412 Jaw Crusher
– Secondary: CH430 Cone Crusher + 3-deck screen
– Tertiary: CV218 VSI for sand shaping

• Outcome: Produced 0–5mm sand with FM 2.8, achieving 98% compliance with ASTM C33.

Key Takeaways

• Invest in automated control systems (e.g., PLCs) to optimize production yield.
• Partner with OEMs for wear-part recycling programs to cut operational costs.
• Modular plants reduce civil work costs by 30% vs. stationary setups.

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