CIVIL ENGINEERING GRADE BENTONITE CLAY
Sodium Bentonite PELLETS
BENTONEX SB PELLETS
Please Note: Prices quoted for Pallets of 20x25Kg and 42x22Kg are only available for delivery to Mainland UK customers. For customers in Ireland and off-shore Islands please contact us for a quotation
This clay is Civil Engineering grade and suitable for use in engineering projects where a slower absorption of water and swelling is preferred. It is commonly used for sealing bore holes, deep ponds, lakes etc (see below).
Properties of Bentonite Clay:
- CAS No: 1302-78-9
- EC No: 215-288-5
- Other names: sodium Bentonite, Montmorillonite, Aluminosilicate of sodium
- Appearance: Pellets ( 1 cm approx )
- Colour: Tan
- Odour: mild
- Bulk Density: 1050 Kg/m3
When bentonite is mixed with water, the water molecules will enter between the clay plates, forcing them apart. While the plates are dispersed, the bentonite slurry becomes quite fluid. However, on standing the particles become oriented with the negative surfaces of the plates being attracted to the positive edges. Viscosity increases and a gel is formed – a reversible effect known as thixotropy.
Bentonite pellets are small, compressed forms of bentonite clay that serve various functions across several industries. Bentonite itself is a naturally occurring clay composed primarily of montmorillonite, which has strong absorbent and swellable properties when exposed to water. Here are the common uses for bentonite pellets:
1. Sealing and Grouting in Groundwater Wells:
- Purpose: Bentonite pellets are widely used to seal groundwater wells, boreholes, and monitoring wells. They expand when exposed to moisture, forming an impermeable seal to prevent the contamination of groundwater.
- Applications: They are typically poured into well casings or boreholes, where they absorb water and swell to create a watertight barrier.
- Benefits: Their swelling action makes them ideal for preventing cross-contamination between water-bearing zones and sealing annular spaces between pipes and the well wall.
2. Environmental Applications:
- Landfill Liners: Bentonite pellets are used in landfill liners and covers, creating barriers that prevent the escape of leachate or the intrusion of groundwater into waste containment areas.
- Lake and Lagoon Sealing: These pellets are often employed in lining ponds, lagoons, and ditches to control water seepage and leakage.
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Bentonite Pellets For Sealing Ponds: Sodium Bentonite Pellets swell up to eighteen times its dry size when it becomes wet. Expanded bentonite forms an impermeable gel seal which makes an excellent pond sealant. Bentonite is environmentally safe and does not affect the water, livestock, or wildlife. When properly applied, it will not harm fish.
When sealing a leaking pond to prevent water loss through seepage, Bentonite Pellets can be applied by sprinkling on the surface of the water and allowing to settle to the bottom (see below for application details). In the case of small ponds, it can be applied with simple hand tools and for larger ponds and lakes, with ordinary farm equipment.
3. Civil Engineering and Geotechnical Applications:
- Tunneling and Trenching: Bentonite pellets are used as a grout in construction projects, such as trenchless tunneling or boring, where they stabilize the surrounding earth and prevent water ingress during excavation.
- Foundation Sealing: In some construction projects, bentonite pellets can be used to create impermeable layers around structures like basements or tunnels to prevent water intrusion.
4. Oil and Gas Drilling:
- Well Sealing: In the oil and gas industry, bentonite pellets are used in the completion of oil wells to seal abandoned wells or to stabilize drilling formations, preventing the movement of fluids between subsurface layers.
5. Waste Management:
- Containment Systems: They are used in the containment of hazardous wastes, acting as a seal to contain the material and prevent the escape of harmful substances into the environment.
6. Agriculture and Horticulture:
- Moisture Retention: In agricultural and horticultural applications, bentonite pellets are added to soil to improve water retention and prevent excessive drainage, especially in sandy soils.
Advantages of Bentonite Pellets:
- Swelling Capacity: Bentonite pellets can expand up to several times their dry volume, providing an effective seal against moisture migration.
- Low Permeability: Once hydrated, they form a low-permeability barrier, ideal for applications where liquid containment or sealing is essential.
- Non-Toxic and Environmentally Safe: Bentonite is a natural material, making it suitable for environmental applications without harmful effects.
Application Rates:
- Clay soils: 5-7 Kg/m2
- Sandy Silt: 10-12 Kg/m2
- Silty Sand: 12-15 Kg/m2
- Clean Sand: 15-20 Kg/m2
- Rock or Gravel: 20/25 Kg/m2
THE SPRINKLE METHOD (Granules or Pellets)
The Sprinkle Method is used where it is not possible to drain the pond or lake. It is considered to be less effective at sealing ponds and reducing seepage compared to the Blanket and Mixed Blanket methods. It is commonly employed for targeted treatment of areas where seepage is suspected to be occurring, rather than treating the complete bed of the pond or lake. The Powdered Bentonite is not recommended for this Method. The GRANULAR Bentonite should be used for this application and for very deep water, the Bentonite PELLETS are preferred. Usage of granules is considered to be safe for fish and wildlife.
See chart above to determine the quantity required per square metre of area being treated. Pour the granules over the surface of the water. The granules will drop down to the bottom of the pond and be drawn into any crevices, holes and cracks. There, they will swell and seal the crevices etc.
Click here for the Specification sheet