Bentonite is a naturally occurring clay composed primarily of montmorillonite, a type of smectite mineral. It forms from the weathering of volcanic ash in the presence of water. Known for its high water absorption, swelling capacity, and adsorptive properties, bentonite is widely used in various industries.
Key Characteristics:
- High swelling capacity: Expands multiple times its dry volume when in contact with water.
- Thixotropic behavior: Becomes fluid when agitated and solid when at rest.
- Ion exchange properties: Can attract and hold positively charged ions (cations).
Types:
- Sodium Bentonite: Swells more, mainly used in drilling, sealing ponds, and as a binder.
- Calcium Bentonite: Less swelling, commonly used in cosmetics, as an adsorbent in bleaching oil, and as a detoxifying agent.
Common Uses:
- Drilling mud in oil and gas exploration.
- Horizontal & Directional drilling (HDD) for stabilisation, lubrication and cooling.
- Foundry sand binder in metal casting(Green Sand moulding).
- Iron Ore Pelletizing as a Binder.
- Civil Engineering and Piling for preventing water ingress, suspends cuttings and stability.
- Ingredient in cat litter and personal care products (face masks, creams)