Bentonite
Bentonite is the common name for naturally occurring clay that contains the active montmorillonite mineral. The special properties of montmorillonite that enable commercial applications include the sub-micron platelet structure, very high surface area (≈800 m2/g), and inherent negative charge in the platelet that is counter balanced by exchangeable cations.
Bentonites are typically classified as either sodium (swelling) or calcium (non-swelling) based on their interlayer exchangeable cations and ability to swell in water. Bentonites with sodium (Na+) ions as the predominant exchangeable cation exhibit a high swelling capability in water, whereas bentonites with calcium (Ca++) ions as the majority exchangeable cation exhibit much lower swelling ability.
Bentonite is known as the “Mineral of 1,000 Uses.” Based on our proven ability to selectively mine for specific applications and modify the surface of the mineral to deliver performance, bentonite clay has major commercial applications in foundry green sand binders, building waterproofing, cat litter, geosynthetic clay liners for environmental uses, iron ore pelletizing, drilling muds, edible oil clarification, animal feeds, and wine/juice clarification. Specialty applications of bentonite clay include asphalt emulsions, catalysts, cosmetics, paints and pharmaceuticals.