Bentonite (Montmorillonite Clay)

Name: Bentonite (Montmorillonite Clay)
Brand: RawSource

At a Glance

Material Family

Mineral Fillers & Pigments

Record Type

UVCB

Primary Role

Color / Pigmentation · Thickening / Rheology

Functional Roles

INCI Name

CI 77004

CosIng Functions

COLORANT

Industries Served

Beauty & Personal Care Coatings & Construction Oil & Gas

Applications & Use Cases

▸ Foundry: Binder for green-sand molds and cores
▸ Drilling fluids: Viscosifier and filtration-control additive in drilling muds
▸ Iron-ore pelletizing: Binder for taconite and iron-ore pellets
▸ Adsorbent: Clarifying and decolorizing agent (Fuller's earth applications)
▸ Suspension agent: Thickener and suspension aid in industrial slurries

Physical Properties

appearance

Pale grey to cream/buff powder or granules (typical)

odor

Odorless (typical)

ph_suspension

8.5-10.5 (typical, 5% sodium-bentonite suspension)

specific_gravity

2.4-2.7 (typical)

bulk_density

800-1100 kg/m3 (typical, powder)

water_solubility

Insoluble; swells and disperses to a colloidal gel

moisture_content

5-12% (typical, as shipped)

Safety & Handling

Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

Request SDS →

HS / Tariff Classification

Harmonized System (HS) Code — 6-digit international heading

2508 . 10

Chapter 25

Salt; sulphur; earths and stone; lime and cement

Heading 25.08

Internationally harmonized (WCO HS)

Subheading 2508.10

6-digit international code — national tariff line adds further digits

Chemical Identity

CAS Number

1302-78-9

Molecular Formula

Al2H2O6Si

Molecular Weight

180.06 g/mol g/mol

IUPAC Name

dioxosilane;oxo(oxoalumanyloxy)alumane;hydrate

INCI Name

CI 77004

PubChem CID

517273

InChI Key

SVPXDRXYRYOSEX-UHFFFAOYSA-N

Synonyms & Trade Names

Montmorillonite Bentonite clay Sodium bentonite Calcium bentonite Smectite clay Wilkinite Aluminium phyllosilicate

Full Description

Bentonite (CAS 1302-78-9) is a natural montmorillonite clay supplied for industrial use. It is used as a binder in foundry molding and core sands, as the principal viscosifier in drilling muds, as an iron-ore pelletizing binder, and as an adsorbent and clarifying agent.

Frequently Asked Questions

What is bentonite mostly used for?

Bentonite (CAS 1302-78-9) is a natural montmorillonite clay used as a binder in foundry green-sand molds and cores, as the principal viscosifier and filtration-control additive in drilling muds, and as a binder for iron-ore pelletizing. It also serves as an adsorbent and clarifying agent and as a suspension aid in industrial slurries. RawSource supplies it in bulk.

What is bentonite made of?

Bentonite is a natural clay composed principally of the smectite mineral montmorillonite, formed from weathered volcanic ash. CAS is 1302-78-9. Sodium and calcium bentonite variants differ in swelling behavior; specify your application for grade matching.

Why is bentonite used in drilling fluids?

Bentonite hydrates and swells in water to build viscosity and a low-permeability filter cake, controlling fluid loss and suspending cuttings in drilling muds. This makes it the principal viscosifier in water-based drilling fluids. RawSource supplies drilling-grade bentonite in bulk.

What is the CAS number and HS code for bentonite?

Bentonite carries CAS 1302-78-9 and is classified under HS 2508.10. It is a natural montmorillonite clay. RawSource provides identity and specification documentation with each bulk shipment.

How is bulk bentonite packaged and priced?

RawSource supplies bentonite in bulk for foundry, drilling, pelletizing, and adsorbent applications, in bags, super sacks, or bulk depending on grade. Pricing is quote-based and depends on grade, volume, and delivery terms. Submit a bulk RFQ with your target quantity and specification for current pricing and lead time.

Related Products

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.