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Clays & Absorbents

Sodium Bentonite

An absorbent aluminium phyllosilicate with high swelling value and instant gelling — suitable for drilling, foundry, sealing, and steelmaking applications.

About Bentonite

Sodium Bentonite is an absorbent aluminium phyllosilicate. Sodium Bentonite expands when wet — it can absorb several times its dry weight in water. It is essentially an impure clay consisting mostly of montmorillonite.

Sodium based Bentonite has excellent colloidal properties and it is often used in drilling mud for oil and gas wells and boreholes for geotechnical and environmental investigations. The property of swelling also makes sodium bentonite useful as a sealant, since it provides a self-sealing, low permeability barrier.

Sodium bentonite is mostly used for large castings that use dry moulds, while calcium bentonite is more commonly used for smaller castings that use 'green' or wet moulds. Bentonite is also used as a binding agent in the manufacture of iron ore (taconite) pellets as used in the steelmaking industry.

Property Specifications

Standard properties for Rawchem Sodium Bentonite. Full datasheets available on request.

PropertyUnitResult
Free Swelling Value (2 g/100 mL)mL32 min
Gelling Time (10% suspension)secInstant (<60)
Methylene Blue Requirementmg/g370 min
Product Fineness (passing 200 mesh)%85 min
Moisture Content%14 max
pH Value (5% suspension)8 – 10
Green Compression Strength (10:4)g/cm²1000 min
Wet Tensile Strength (10:4)g/cm²25 min
High Swelling Value
Offers high swelling value and instant gelling for effective sealing and drilling mud applications.
Uniform Particle Size
Uniform particle size results in good coating to other components, improving foundry performance.
Stable Mould Formation
High GCS & WTS with high-temperature resistance results in stable mould formation for all foundry types.
Universal Foundry Compatibility
Suitable for all foundry infrastructure: Manual, Semi-Automatic, High Pressure, and more. Easy shake-out for casting.

Explore Bentonite Applications

Drilling mud, sealing, foundry castings, iron ore pelletising and geotechnical investigations.

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