• Sodium

• Calcium Bentonite

Bentonite has been widely used as a foundry-sand bond in iron and steel foundries. Sodium bentonite is most commonly used for large castings that use dry molds, while calcium bentonite is more commonly used for smaller castings that use "green" or wet molds.

Bentonite is also used as a binding agent in the manufacture of iron ore (taconite) pellets as used in the steelmaking industry.