Bentonite: Properties, Production & Industry-Specific Specifications

Introduction

Bentonite is a naturally occurring clay composed mainly of montmorillonite, formed by the alteration of volcanic ash. It is highly absorbent, capable of swelling several times its dry volume when in contact with water. This unique property, combined with its colloidal and bonding characteristics, makes bentonite an essential material across numerous industries.

Production Process

The manufacturing of bentonite involves open-pit mining, followed by drying, crushing, and micronizing. Depending on its intended use, it is further purified and processed to meet specific particle size, swelling index, moisture, and viscosity requirements.

Industry-Wise Applications & Specifications

1. Oil Well Drilling (API Grade Bentonite)

Used as a drilling mud to cool and lubricate the drill bit and stabilize boreholes.

Specifications

• Viscosity: ≥30 cP
• Yield: ≥85 bbl/ton
• Moisture: ≤13%
• Filtration Loss: ≤15 ml (per API 13A Section 9)

2. Foundry (Foundry Grade Bentonite)

Acts as a binder in green sand molds for casting iron and steel.

Specifications

• Montmorillonite: ≥70%
• Moisture: 10–12%
• Swelling Volume: High (≥20 ml/2g)
• Gelling Time: Fast, for rapid mold setting

3. Iron Ore Pelletization (Pellet Grade Bentonite)

Used as a binder in manufacturing iron ore pellets for blast furnaces.

Specifications

• Montmorillonite: ≥85%
• Moisture: ≤12%
• LOI: ≤13%
• Fineness: 200 mesh ≥90%
• Low silica and alumina content

4. Civil Engineering & Construction

Used in diaphragm walls, piling, tunneling, and waterproofing.

Specifications

• Swelling Index: ≥24 ml/2g
• Viscosity: ≥30 cP
• Filtration Loss: ≤15 ml
• Particle Size: 90% passing through 200 mesh

5. Cosmetics & Pharmaceuticals

Used in face masks, creams, and detoxifying agents.

Specifications

• Free from heavy metals and microbes
• pH: 8.5–10.5
• Fineness: 99% below 200 mesh
• Whiteness: High (for aesthetic appeal)

Conclusion

With access to high-grade reserves, strict adherence to international standards (API, IS, ASTM), and customized packaging and logistics, we are a preferred bentonite exporter from India—capable of supplying industry-specific grades at competitive prices globally.