Bentonite Specifications

High Swelling Bentonite

• High-swelling bentonite is termed sodium bentonite and is known for its superior absorption properties. It is capable of absorbing five times its own weight in water and, when fully saturated, can occupy a volume fifteen times its dry bulk. However, on drying, it returns to its original volume. High-swelling bentonite's swelling and drying properties are infinitely reversible in pure water, giving the mineral a reputation as an excellent water-sealant.

Low Swelling Bentonite

• The low-swelling type of bentonite achieves a saturated volume from 1.5 to 7 times its bulk when dry. As such, it is considered a lower quality product, as more low-swelling bentonite is required to effect a reduction in water seepage than high-swelling bentonite.

Soil Sealant

• Bentonite can also be used in soil sealants by applying it as a waterborne material onto a sodden perimeter. Ideally, the bentonite should be placed at a profound depth in the chosen channel bed materials where leaking occurs, and should swell upon saturation, plugging the offending gaps. On the other hand, bentonite is known to form a surface coating on the soil which contracts when it dries, and thus does not re-form to form an effective sealing layer.

Modified Soil Earth Lining

• Bentonite is used in modified soil earthen linings. In this capacity, it can be added to soils that provide inadequate protection against seepage, to improve sealing capacity. This technique is often called a mixed blanket technique and involves mixing a portion of bentonite with between 6 to 12 inches of soil, and must be applied continuously through a well-compacted layer. High compaction achieves a lower permeability, and as much as 90 percent seepage reduction can be achieved.

Other Applications of Bentonite

• Over and above its excellent properties as a sealant, bentonite has a wide variety of applications in fungicides, sprays, detergents, polishes, ceramics, papers, cat litter, poultry feed, cleaners, cosmetics, medicines, and lagoons.