What is Bentonite?
Bentonite is a clay mineral which is largely composed of Montmorillonite, which is mainly a hydrous aluminum silicate. It is a highly colloidal and plastic clay with the unique characteristic of swelling to several times its original volume when placed in water.
Bentonite was formed from volcanic ash deposited in an ancient sea, and modified by geological process into the present Sodium Bentonite. Bentonites were calculated to have accumulated between 74.5 and 70 million years ago. At that time, the Wilcox area was the center of a huge shallow inland sea which stretched from the Arctic Ocean to present day Mexico and was at least 1600 kilometers wide.
Bentonite has been called the clay of a thousand uses. Sodium Bentonite is noted for its affinity for water which gives it tremendous selling properties. Sodium Bentonite contains exchangeable sodium cations. When dispersed in water it breaks down into small plate-like particles negatively charged on the surface, positively charged on the edges. This unique ion exchange is responsible for the binding action which takes place. Bentonite's small plate-like particles provide a tremendous potential for surface area. It forms thixotropic gels with water even when the amount of Bentonite in such gels is relatively small. These characteristics give Bentonite an enormous range of potential uses. For instance, this special clay can be used as an animal feed binder, a natural soil sealant or drilling mud, a foundry sand binder, or as a stucco and mortar plasticizer.
Bentonite is referred to as the "The Clay of 1000 uses"
Foundries, Well drillers, Iron ore manufacturers and producers of kitty litter are the main consumers of Bentonite.
Foundries use Bentonite when pouring metal cast molds. The clay withstands higher temperatures and the excessive heat will not cause the clay to lose its chemical structure.
Well drillers use Bentonite when drilling oil or gas wells. Bentonite will absorb 10 times it weight in water. The bentonite clay is mixed with water and other minerals to form a drilling mud, which seals up the wall of the well bore and allows the rock chips to be pumped back to the surface.
Iron ore manufacturers add Bentonite to crushed taconite to form pellets, which can then be transported to a steel mills.
Because Bentonite will absorb moisture, new applications are continually being developed. Clumping cat litter and toxic waste cleanup are two of those new markets.
Bentonite is also used as a:
• Sealant in sanitary landfills and lagoons
• Water purification systems
• Binder in fertilizers and animal feed products
• Carrier for insecticide