Bentonite is a very soft plastic clay consisting predominantly of montmorillonite, a fine particle sized hydrous aluminum silicate and member of the smectite group.
Bentonite is rich in resources. According to<World Mineral Resources Annual Review 2014>, the world's proven reserves are about 2.5 billion tons, mainly distributed in the Pacific Rim, the Indian Ocean, the Mediterranean Sea, and the Black Sea.
The main resources are the United States, China, Russia, Greece, Turkey, Germany, Italy, Mexico and Japan. Among them, the proven reserves of the United States, China and Russia account for 80% of the world's total reserves. The main source of sodium-based bentonite is in Wyoming, USA, and there are also distributions in Russia, Italy, Greece and China.
Bentonite can be used for foundry, oil drilling, paper industry, tunneling, ore pelletizing, dam, lake and landfill sealing, water treatment, pet litter and feed markets worldwide.
Bentonite is used as a bonding material in the preparation of molding sand for the production of iron, steel and non-ferrous casting. The unique properties of bentonite yield green sand moulds with good flowability, compactability and thermal stability for the production of high quality castings.
Bentonite is used as a binding agent in the production of iron ore pellets. Through this process, iron ore fines are converted into spherical pellets, suitable as feed material in blast furnaces for pig iron production, or in the production of direct reduction iron (DRI).
Another conventional use of bentonite is as a mud constituent for oil and water well drilling. Its roles are mainly to seal the borehole walls, to remove drill cuttings and to lubricate the cutting head.