Bentonite is a mineral from the clay group and is composed of swollen and crystalline quasi-clay minerals. It generally contains montmorillonite and a small amount of bidellite, and is formed by chemical changes in volcanic ash. In other words Bentonite means clay that has 90-85% of montmorillonite mineral. Bentonite is an adsorbent of aluminum and contains elements such as sodium, calcium, aluminum and potassium. If Bentonite is poured into water, it becomes bulky after mixing. After drying this compound is also stronger than concrete. The most important applications of Bentonite include foundry, earth wells, cosmetics and medicine, oil well drilling, construction and civil engineering, spray production and food additives.
Chemical properties of Bentonite
Bentonite belongs to the family of plate silicates and has a three-layer structure. In its structure, an octagonal aluminum layer is placed between two layers of quadrilateral silica. The quadrilateral plates are made of SiO4, and each quadrilateral is connected to its adjacent quadrilaterals by three oxygen atoms. Bentonite contains hydroxyl (OH) which are located in the center of the hexagonal ring. The quadrilateral plates are connected by octagonal plates. The stem distance in this group is 14 angstroms. This distance can vary from 9.6 to 21.4 angstroms due to the ability of smectite to absorb water molecules.
