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Bentonite Supplier & Exporter — Drilling, Foundry and Feed Grade Clay

Al₂O₃·4SiO₂·nH₂O Montmorillonite Clay · MMT 65 – 86%

Six processed grades of bentonite off one montmorillonite deposit — drilling clay with a 40-point gel index, foundry binder, feed and bedding grades, earthing backfill, and the carrier grade used to pastille sulphur bentonite fertilizer. Each grade is milled and screened to its own physical specification, with a batch-specific Certificate of Analysis per shipment.

Bulk bentonite clay — sodium and calcium montmorillonite for drilling mud, foundry sand and feed binding — B2B export supplier Raivaco MMT ≥ 65%

Supply capability at a glance

> 86%

Montmorillonite, milled grades

25 MT

MOQ — bagged (1 × 20ft)

7–14 days

Lead time, standard grades

Per batch

Certificate of Analysis

Physical Properties

Formula

Al₂O₃·4SiO₂·nH₂O

Mineral

Montmorillonite

CAS No.

1302-78-9

Mohs Hardness

1.0 – 2.0

Cation Exchange

63 – 110 meq/100 g

Moisture

4 – 8%

Synonyms: Bentonite Clay, Sodium Bentonite, Calcium Bentonite, Montmorillonite, Fuller’s Earth, Drilling Clay · EINECS 215-108-5 · Cream to pale-grey powder or granule; swells and forms a thixotropic gel in water.

Grades & Chemical Analysis

Six grades off the same deposit. Drilling and foundry clay run the higher-iron chemistry; feed, earthing and bedding grades run the low-iron, high-silica chemistry and differ on water absorption, swelling and grading. Select a grade to view its full analysis.

The feed, earthing and bedding grades are milled from the same low-iron seam and therefore share one chemical analysis; they are separated on water absorption, swelling and grading. Values are typical specification ranges; a batch-specific CoA is issued per shipment.

Bentonite Grades — Physical Comparison

The properties that actually decide which grade fits a job: how much water the clay takes up, how far it swells, and how finely it is ground.

Comparison of bentonite grades by water absorption, swelling, grading and cation exchange capacity
GradeWater AbsorptionSwellingGradingCation Exchange
Drilling31 – 35 (2 h index)99% < 0.075 mm
FoundryMilled powder
Feed & Poultry680 – 750%22 – 25 mL/2 g400 mesh100 – 110 meq/100 g
Earthing300 – 700%22 – 25 mL/2 g400 mesh100 – 110 meq/100 g
Bedding560 – 580%17 – 20 mL/2 g1.5 – 3.5 mm63 meq/100 g
Sulphur CarrierMilled powder

Dashes mark properties that are not part of that grade’s acceptance test set — drilling clay is judged on gel and swelling index, foundry clay on green and dry compression strength.

Bespoke Production

Need a different mesh, activation or gel index?

If none of the grades above matches your target chemistry, fineness, or packaging, tell us your requirements — we produce custom grades to your exact specification.

Applications

Bentonite earns its keep on one property — a plate-shaped clay particle that swells, holds water and exchanges cations. What changes between grades is how much.

Drilling Fluids

Viscosifier and filtration-control clay in water-based muds and HDD.

Foundry Green Sand

Binder giving green and dry compression strength in moulding sand.

Iron Ore Pelletizing

Binder holding green pellets together before induration.

Animal Feed

Pellet binder, anti-caking agent and mycotoxin binder.

Earthing & Grounding

Low-resistivity backfill around earth rods and grounding pits.

Civil Engineering

Slurry walls, tunnelling, pond lining and geosynthetic clay liners.

Sulphur Bentonite Fertilizer

Carrier clay that swells and disperses the sulphur pastille in soil.

Cat Litter & Bedding

Clumping granular absorbent for animal bedding.

Beverage & Oil Clarification

Protein removal in wine and juice; bleaching earth for edible oils.

Packaging, Logistics & Trading Terms

How we mill, bag, certify and ship bentonite. Terms can be adapted by agreement — tell us what your operation needs.

Minimum Order Quantity
1 × 20 ft container (approx. 25 MT) bagged. 500 MT minimum for bulk vessel. Trial quantities available for qualification.
Packaging
25 kg and 50 kg PP bags, 1–1.5 MT woven jumbo bags, or bulk. Feed and bedding grades can be supplied with a moisture-barrier liner.
Incoterms & Loading Ports
EXW, FOB, CFR and CIF (Incoterms® 2020). Standard loading at Bandar Abbas and Bandar Imam Khomeini; other ports by arrangement.
Quality Certification
Batch-specific CoA with every shipment covering montmorillonite content, water absorption, swelling, grading and moisture. Feed grade adds a heavy-metal panel. SGS / Bureau Veritas inspection at buyer’s cost.
Lead Time
7–14 days for standard grades after order confirmation; 15–25 days for custom-milled or specially packed material.
Storage & Handling
Store under cover on pallets, away from standing water. Bentonite is hygroscopic — bags that take on moisture cake and lose swelling capacity, which is the one property every grade is bought for. Correctly stored it has no shelf-life limit.

Certificate of Analysis

A batch-specific CoA is issued with every shipment. Third-party inspection by SGS, Bureau Veritas or an inspector of your choice can be arranged at the buyer’s cost.

Ready to quote

Send us your grade, tonnage, destination port and packaging and we will return a firm FOB/CFR/CIF price with lead time.

Request a Bentonite Quote

Bentonite — Frequently Asked Questions

What is the difference between sodium and calcium bentonite?
The exchangeable cation sitting between the clay platelets. Sodium bentonite swells far more — up to fifteen times its dry volume — which is what makes it the drilling, sealing and pelletizing clay. Calcium bentonite swells much less but has a higher adsorption capacity, which suits bleaching earth, feed and litter uses. Calcium clay can be soda-activated to behave more like sodium clay.
Which grade do I need for water-based drilling mud?
The drilling grade. It runs 65–67% montmorillonite with a gel index of 33 after eight hours and 40 after twenty-four, a two-hour swelling index of 31–35, and 99% passing the 0.075 mm (200 mesh) screen. If your programme is written against API 13A, tell us at enquiry stage and we will confirm the yield and filtrate figures before shipment.
Is the feed grade tested for heavy metals?
Yes. Every feed-grade certificate carries a heavy-metal panel: lead, cadmium and nickel are reported as not detected, mercury at 0.22 ppm and arsenic at 2 ppm. Montmorillonite content is above 86% and cation exchange capacity runs 100–110 meq/100 g, which is what drives the toxin-binding performance.
What makes earthing bentonite different from ordinary bentonite?
Nothing in the chemistry — it is the same low-iron clay as the feed grade. What matters for a grounding pit is that the backfill holds moisture against the electrode so resistivity stays low through a dry season, which is why the grade is specified on water absorption (300–700%) and cation exchange capacity rather than on gel index.
Can you supply bentonite for sulphur bentonite fertilizer?
Yes. The carrier grade is the clay used to pastille 90/10 sulphur bentonite: silica 60–70%, alumina 11–14%, sodium oxide 2–3% and loss on roasting 5–8%. The sodium content is what makes the pastille swell and fracture in the soil so the sulphur oxidises at a usable rate. We supply the elemental sulphur as well.
What is the minimum order quantity for bentonite?
One 20 ft container, approximately 25 MT, for bagged material. Bulk vessel shipments start at 500 MT. Trial quantities can be arranged so you can qualify the clay in your own mud, sand or feed system before committing to a full order.

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