Bentonite is a versatile clay mineral widely used in drilling and mining due to its unique properties, such as swelling capacity, viscosity, and thixotropy. Below are its key applications in these industries:
1. Bentonite in Drilling (Drilling Mud)
Bentonite is a crucial component of water-based drilling fluids (mud) used in oil, gas, and water well drilling. Its functions include:
– Lubrication & Cooling: Reduces friction and cools the drill bit.
– Suspension & Hole Stability: Prevents borehole collapse by forming a gel-like structure.
– Cuttings Removal: Carries drilled cuttings to the surface.
– Sealing Formation Walls: Forms a low-permeability filter cake to prevent fluid loss.
– Viscosity Control: Provides rheological properties for efficient drilling.
Types of Bentonite Used:
– Sodium Bentonite (high swelling capacity, preferred for most drilling applications).
– Calcium Bentonite (lower swelling, sometimes activated with soda ash).
.jpg)
2. Bentonite in Mining
In mining, bentonite serves multiple purposes:
# a) Pelletizing (Iron Ore & Mineral Processing)
– Acts as a binder in iron ore pelletization, improving strength and handling.
– Helps form uniform pellets for blast furnaces.
# b) Tailings Management & Slurry Control
– Used in backfilling mine voids to stabilize waste materials.
– Reduces water seepage in tailings ponds.
# c) Tunneling & Underground Support
– Mixed with cement for grouting to stabilize tunnels and shafts.
– Prevents groundwater inflow due to its sealing properties.
# d) Gold & Precious Metal Extraction
– Used in heap leaching to improve permeability and metal recovery.
Key Properties Making Bentonite Ideal for Drilling & Mining:
✔ High swelling capacity (up to 15x its volume).
✔ Excellent viscosity and thixotropic behavior (gel strength).
✔ Low permeability when hydrated (seali
ability).
✔ Strong binding properties for agglomeration.
Types of Bentonite Grades:
| Grade | Application |
|——–|————|
| API Standard (OCMA/API 13A) | Oil & gas drilling mud |
| Foundry Grade | Binder in pelletizing |
| Civil Engineering Grade | Grouting, sealing |
| Non-treated/Calcium Bentonite | Lower