Bentonite is a naturally occurring clay formed from volcanic ash deposits over millions of years. It is highly valued across industries for its absorption, swelling, and binding properties. But not all bentonite is the same. The two most common types are Sodium Bentonite and Calcium Bentonite — and while they belong to the same family, their properties and applications are quite different.
In this blog, let’s explore the differences between sodium bentonite and calcium bentonite, their unique characteristics, and where each is used.
🔹 What is Sodium Bentonite?
Sodium Bentonite is a clay that is rich in sodium ions (Na⁺). Its standout feature is its exceptional swelling capacity. When mixed with water, it can expand up to 15–20 times its original volume, creating a thick, gel-like substance.
Key Properties:
- High water absorption
- Strong swelling and sealing ability
- Excellent plasticity and cohesion
Common Uses:
- Drilling mud in oil & gas exploration
- Waterproofing ponds, landfills, and canals
- Foundry sands for metal casting
- Cat litter (clumping type)
- Slurry walls and geotechnical engineering projects
🔹 What is Calcium Bentonite?
Calcium Bentonite is rich in calcium ions (Ca²⁺) and has low swelling capacity compared to sodium bentonite. Instead of expanding, it primarily works through adsorption — binding toxins, oils, and impurities to its surface.
Key Properties:
- Low water absorption
- Stable structure with limited swelling
- High adsorptive ability
- Softer and less sticky compared to sodium bentonite
Common Uses:
- Cosmetics and skincare (face masks, detox products)
- Pharmaceuticals (digestive remedies, detox clay)
- Animal feed additive
- Purification of oils, fats, and beverages
- Binder in iron ore pellets and feed pellets