Bentonite is a highly colloidal clay mineral which gets its name from the place where its presence and usages were first discovered – Fort Benton, America. The multiple properties of bentonite namely hydration, swelling, water absorption, viscosity, thixotropy make it a multi-application product for diverse industries. Primarily two varieties of bentonite are available - sodium bentonite (high swelling, gelling and thermal durability) and calcium bentonite (more commonly available worldwide but with less swelling).
|Sr No.||Chemical Analysis Of Bentonite|
|1||SiO2||37 - 46|
|2||Al2O3||22 - 28|
Bentonite has high swelling properties along with good viscosity and liquid limit. These properties are highly valued in most of the industrial applications. Sodium bentonite is well suited as a binder in the preparation of pellets, and in foundry and oil - well drilling mud. Bentonite also acts as a suspending agent in oil - well drilling fluids. Bentonite exhibits good green strength along with high hot and dry strength which helps in preventing moulds from breaking or cracking during the pouring or cooling processs in the foundry industry. Owing to high green strength resulting from its property to absorb and then release moisture, bentonite is used in iron ore pelletisation. Sodium-based bentonite of 75 mm size finds suitability in iron ore pelletisation for bonding by user industries. Bentonite has also remarkable colloidal and waterproofing properties. Bentonite gels are used as a carrier for a number of cosmetic preparations, toothpastes, creams, etc.
Bentonite is also used in chemical, rubber, insecticide & pesticide industries and in civil construction works. Bentonite in the form of fine powder free from dirt and other foreign matter and of least swelling property is used in ceramic industry.