Free Reference · Bulk Material Properties

Bulk Material Properties
Reference Database

Bulk density, particle size, angle of repose, flowability index, and Carr Index for 40+ industrial materials commonly handled in Malaysian process plants. Use this as a starting point for equipment selection — always verify against your actual material sample.

⚠ These values are typical ranges from published literature and ENZAC project data. Actual values vary by source, processing history, and moisture content. Always obtain a material test report for critical system design. ENZAC can arrange material testing →

Bulk Density (kg/m³)
Mass per unit volume in loose-poured condition. Used for silo/hopper sizing and conveying system design.
Light: < 400 kg/m³
Medium: 400–800 kg/m³
Heavy: > 800 kg/m³
Particle Size (D50, micron)
Median particle diameter from sieve analysis or laser diffraction. Determines conveying method and filter sizing.
Fine powder: < 100 µm
Powder: 100–500 µm
Granule: 0.5–5 mm
Coarse: > 5 mm
Angle of Repose (°)
The steepest angle a material heap maintains without sliding. Determines silo cone angles and hopper slopes.
Free-flowing: < 30°
Normal: 30–40°
Cohesive risk: > 45°
Design rule: Add 10° safety margin to discharge cone
Carr Index (Flowability)
Compressibility index = (tapped − bulk density) / tapped × 100. Lower = better flow.
< 10: Excellent (free-flowing)
11–20: Good
21–35: Fair — flow aids needed
36–40: Poor — cohesive
> 40: Very poor — mechanical aids required
Material Also Known As Category Bulk Density
(kg/m³)		 Particle Size
(D50)		 Angle of
Repose (°)		 Carr Index
(%)		 Flowability Abrasion
(Mohs)		 Hygroscopic?
How to Use This Data

Engineering guidance for using bulk material property data.

For System Design
Use bulk density for silo volume sizing: Volume = Mass / (bulk density × fill factor). Use angle of repose for hopper slope design: cone angle must exceed AoR by at least 10°. Use Carr Index to determine whether flow aids (vibrators, fluidisation pads) are required.
For Conveying Selection
High abrasion (Mohs > 3) → dense phase with ceramic lining mandatory. Fine powder (D50 < 100µm) + good flowability → dilute phase viable. Cohesive (Carr Index > 35) or sticky → mechanical conveying preferred. Fragile granules → dense phase at minimum velocity.
Always Verify
Published values are ranges. Your actual material may differ due to: particle shape, surface coating, moisture content, storage history, and production batch variability. ENZAC recommends material testing — we can arrange bulk density, particle size, angle of repose, and Jenike shear cell testing. Contact us →