Bentonite is an industrial ore that is mined throughout the world. It is formed from the alteration of siliceous, glass-rich volcanic rocks such as tuffs and ash deposits. The major mineral in bentonite is montmorillonite, a hydrated sodium, calcium, magnesium, aluminum silicate. Bentonite is known as “swelling” or “plastic” clay that effectively sorbs and retains relatively high amounts of water.
Bentonite has been mined for centuries, but for over 75 years the most famous deposits have been mined commercially in the United States. There are two types of bentonite produced in the U.S.: “Wyoming” or “western” bentonites are mined from sodium bentonite deposits in Wyoming, South Dakota and Montana; “southern” bentonites are mined from calcium bentonite deposits in the Gulf Coast states of Mississippi and Alabama.
Bentonite possesses strong colloidal properties and its volume increases several times when it comes in contact with water. These unique swelling and adhesive properties make bentonite ideal for use in an extensive range of applications.
It is used as a binding agent in the production of iron ore pellets; as a flow control agent in paints, dyes and polishes; as the clumping agent in clumping cat litter; as a sealant and lubricant in oil and water-well drilling; and in various pharmaceutical and cosmetic products.