How To Classify Quartz Sand Into 40–80, 80–120, And 120–200 Mesh Fractions

Producing three commercial quartz sand grades: 40–80 mesh, 80–120 mesh and 120–200 mesh requires precise multi-stage classification. The process can be configured via a multi-deck vibrating screen system for dry processing, or a combination of hydrocyclones and vibrating screens for wet quartz sand. Both routes are widely used in glass, foundry and filler quartz production.

Mesh Reference Apertures

• 40 mesh: 0.425 mm
• 80 mesh: 0.180 mm
• 120 mesh: 0.125 mm
• 200 mesh: 0.075 mm

Target fractions:

1. 40–80 mesh: particles pass 40 mesh, retained on 80 mesh
2. 80–120 mesh: particles pass 80 mesh, retained on 120 mesh
3. 120–200 mesh: particles pass 120 mesh, retained on 200 mesh

Process Option 1: Multi-deck Vibrating Screen (Dry Classification)

This is the preferred route when raw quartz sand has low moisture (<3%), and dust collection is available.

Screen deck layout (top to bottom)

1. Top deck: 40 mesh screen. Oversize >40 mesh is returned for regrinding. Undersize drops to the second deck.
2. Second deck: 80 mesh screen. Oversize retained here = finished 40–80 mesh quartz sand. Undersize falls to third deck.
3. Third deck: 120 mesh screen. Oversize retained here = finished 80–120 mesh quartz sand. Undersize falls to fourth deck.
4. Fourth deck: 200 mesh screen. Oversize retained here = finished 120–200 mesh quartz sand. Undersize <200 mesh is fine tailings or filler material.

Recommended operating parameters

• Screen type: Linear vibrating screen is better for fine mesh dry quartz classification.
• Vibration frequency: 18–20 Hz (1080–1200 RPM)
• Amplitude: 2.0–3.0 mm
• Screen inclination: 5°–8° (small angle for fine particle retention accuracy)
• Screen media: Modular polyurethane fine screen panels to resist quartz abrasion and reduce blinding.
• Feeding: Uniform low-thickness material bed; high feed rate will reduce classification sharpness.
• Dust control: Full negative pressure dust enclosure to contain silica dust.

Process Option 2: Wet Classification (Hydrocyclone + Fine Vibrating Screen)

Use when raw quartz sand has high moisture, or dry fine screening suffers from severe dust and particle agglomeration.

1. Prepare quartz sand slurry with solid concentration 25–35%.
2. Primary hydrocyclone cluster removes coarse >40 mesh particles. Underflow goes to the screening system.
3. Multi-deck wet vibrating screen with 80/120/200 mesh PU self-cleaning panels separates the three target fractions.
4. Each fraction is discharged separately, then sent to dewatering screens or filter presses for moisture reduction.
5. Hydrocyclone overflow carries fine <200 mesh silt and ultra-fine quartz for separate recovery.

Key Operational Control Points

1. Feed particle size control
   Raw feed must be pre-scalped to remove oversize >40 mesh lumps. Any large particles damage fine mesh panels and disrupt particle stratification.
2. Screen blinding prevention
   Dry: Keep feed moisture below 3%. Add ultrasonic anti-blinding modules if sticky fine powder accumulates.
   Wet: Use PU self-cleaning screen panels with flexible strips; maintain low-pressure water spray on screen surface.
3. Classification sharpness adjustment
   If too many fine particles remain in the 40–80 mesh product: reduce feed rate, slightly increase vibration amplitude.
   If coarse particles leak into the 120–200 mesh fraction: check screen panel wear and seal leakage between decks.
4. Sampling and quality monitoring
   Collect samples from each outlet hourly. Run sieve analysis to verify PSD. Adjust feed flow and vibration settings when particle distribution drifts out of specification.

Advantages & Limitations

Dry multi-deck screening

✅ Lower water consumption, no dewatering required; simple process layout
❌ Strict moisture limit; silica dust risk; fine mesh wears fast with high-abrasion quartz

Wet classification

✅ Excellent anti-blinding performance, sharper cut points; suitable for sticky quartz sand
❌ Higher water consumption; finished sand needs dewatering; extra wastewater treatment system

For high-volume production of foundry quartz sand (40–80 mesh dominant): dry multi-deck vibrating screen.

For high-purity fused silica raw material requiring tight particle distribution: wet hydrocyclone + fine screen combination.