Bentonite

Bentonite is a clay or quasiclay mineral composed of montmorionite and a small amount of bide lite (a richer type of aluminum bentonite). The term bentonite was first coined in 1898 by Knight to refer to clay extracted from the Benton shale at the time. It is named after Shale Benton, located 400 miles north of the Rock River. Iranians have known bentonite for a long time and were familiar with some of its properties, such as washing clothes and as a cleaning agent. Ibn Sina also mentioned this mineral as a brittle substance that dissolves well in water. In the past, this substance was used orally in some parts of Iran, which is still very rare in some villages. From a medical point of view, these people are accustomed to eating mud due to calcium deficiency. Bentonites are formed in two ways, hydrothermal and sedimentary, the sedimentary type is the most important type of bentonite deposits in the world. Bentonite belongs to the family of plate silicates and smectite group and has a threeayer structure in terms of construction. An octagonal aluminum layer is placed between two layers of quadrilateral silica and is mainly on two types of swollen or sodium and non-swollen or calcium. But industrially, bentonites are classified as follows: