SODIUM BENTONITE

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Sodium bentonite expands when wet and can absorb several times its dry mass in water. It is mostly used in drilling mud for oil and gas wells and for geotechnical and environmental investigations.

 

The property of swelling also makes sodium bentonite useful as a sealant, especially targeted for sealing subsurface disposal systems for spent nuclear fuel and for quarantining metal pollutants of groundwater. Similar uses include making slurry walls, waterproofing of below-grade walls, and forming other impermeable barriers—for example, to plug old wells, or as a liner in the base of landfills to prevent migration of leachate into the soil.