About Calcium Bentonite
Calcium bentonite is a montmorillonite clay in which calcium is the main exchangeable cation. It swells far less than sodium bentonite, so it stays workable at higher loadings and does not thicken a formulation excessively. What it offers instead is a large internal surface, steady cation exchange capacity and dependable absorbency.
Those properties suit applications where the clay must take up liquid, hold an active ingredient or extend a formulation without building viscosity. Formulators use our calcium grade as a carrier for agrochemicals and micronutrients, as a plasticising filler in ceramic bodies, and as an absorbent for oil, grease and industrial spills. Its natural plasticity also helps green strength in ceramic and moulded products, and it serves as a starting material for activated grades.
We process calcium bentonite from selected deposits, drying and milling it to a controlled fineness so that it disperses evenly and flows consistently through feeders and blenders. Powder and granular forms are available, and particle size, moisture and bulk density can be tuned to your process. Typical properties are set out on the Technical Data Sheet, and every lot is supported by a batch Certificate of Analysis from our NABL-accredited laboratory. Samples are available for formulation trials.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| Swell index | 8–15 ml/2 g | ASTM D5890 |
| Cation exchange capacity | 50–80 meq/100 g | Methylene blue, internal method |
| Moisture | ≤ 12 % | Internal method |
| pH (5 % suspension) | 7.5–9.0 | Internal method |
| Passing 75 µm (powder form) | ≥ 90 % | Wet sieve, internal method |
| Loose bulk density | 0.7–1.0 g/cm³ | Internal method |
| Colour | Off-white to grey | Visual |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA.
Key features & benefits
Controlled, moderate swell
A swell index well below that of sodium grades lets calcium bentonite be loaded at higher levels without turning a slurry, paste or blend too thick to process or pump.
Good absorbency
The open, layered structure takes up water, oils and other liquids readily, which makes the clay useful both as an absorbent and as a base for free-flowing powder formulations.
Carrier compatibility
Surface area and exchange capacity help the clay hold liquid or powder active ingredients evenly. Customers should verify compatibility and stability with their own actives before scale-up.
Natural plasticity
Fine calcium bentonite improves the workability and green strength of ceramic bodies and moulded products, helping shapes hold together between forming and firing or curing.
Adjustable particle size
Supplied as micronised powder or as granules, with fineness and granule range set to suit blending, granulation, spreading or direct use as a floor absorbent.
Applications
Agrochemical and micronutrient carrier
Used as a carrier and diluent for granular and powder crop-protection products and micronutrient blends, subject to local regulatory approval of the finished formulation in each market.
Ceramic bodies and glazes
Added in small proportions to ceramic bodies to raise plasticity and green strength, and to glaze slips to help keep heavier particles in suspension during application.
Industrial absorbent
Granular calcium bentonite is spread over oil, coolant and grease spills on workshop and factory floors, then swept up once it has absorbed the liquid.
Filler and extender
Used as an economical mineral extender in adhesives, putties, moulded goods and other formulations where a fine, chemically stable clay filler is acceptable and a small rise in body is useful.
Usage & handling
- Carrier formulations: achievable loading of the active depends on its viscosity and your free-flow target; run small batch trials first.
- Ceramic bodies: typical additions are around 1–5 % of the dry body mass, adjusted to the plasticity required.
- Spill absorption: spread an even layer over the spill, allow contact time, sweep up and dispose of according to local regulations.
- Storage: keep in sealed bags in a dry, covered area to protect absorbency and flow.
Packaging & supply
- 25 kg and 50 kg HDPE or paper bags
- 1 MT and 1.2 MT jumbo (FIBC) bags
- Custom or private-label packaging on request
Frequently asked questions
How is calcium bentonite different from sodium bentonite in practice?
Calcium bentonite swells far less, so it is chosen where you want absorbency, adsorption or plasticity without a large rise in viscosity. Sodium bentonite is chosen where swelling and sealing matter, as in liners or drilling fluids. In carrier, filler and absorbent uses, calcium bentonite usually allows higher loadings and easier handling, while still offering the surface activity of montmorillonite.
Can calcium bentonite be used as a pesticide or agrochemical carrier?
Calcium bentonite is used as a carrier and diluent in agrochemical formulations. Whether a specific product can be registered depends on the active ingredient, the formulation and the rules in each country. We supply the clay with its Technical Data Sheet, MSDS and batch CoA to support your registration work, and customers should verify suitability and regulatory acceptance before commercial use.
Can calcium bentonite be converted to sodium bentonite?
Yes. Calcium bentonite can be activated with soda ash, which exchanges calcium for sodium on the clay surface and raises swelling and viscosity. We use this route for some of our sodium-type grades. If your application needs an intermediate swell between our calcium and sodium grades, a custom activation level can be developed and sampled for trials.
What particle sizes of calcium bentonite are available?
Standard supply is a fine powder with at least 90 % typically passing 75 µm, plus granular forms for absorbent and carrier uses. Granule ranges and powder fineness can be adjusted to your blending or granulation equipment. Share your target sieve analysis or bulk density, and we will confirm a matching grade or prepare a sample to that specification.