Alternative (Trade) Names Bentonite Mineral, Amargosite, Taylorite
HS Code 25081000
Physical and Chemical Properties
Chemical Formula (Al2O3-4SiO2-4H2O)
Appearance Gray, Cream
Density 1 g/cm3
PH 9-10
Flammability Non-flammable


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.

کاربرد ها

Bentonite has many applications due to its softness, swelling properties, ability to mix with water, kneading, adhesion, and absorbency. Industrial applications of this material include use in drilling mud compounds, foundry industries, construction, pharmaceutical and detergent industries. Other applications of Bentonite include as livestock and poultry feed and pesticides, paint production, water and oil purification, etc.

Application of Bentonite in drilling industry

Bentonite ore is used in drilling deep oil and gas wells (3000 to 5000 thousand meters). Bentonite has been used as a drilling mud for many years due to its suspension and swelling power. To do this, Bentonite is mixed with water and injected into drilling wells. This compound covers the wall with a gel form and fills the cracks and crevices of the wall and reduces water. Sodium Bentonite or swollen Bentonites are used in oil and gas drilling. When Bentonite is mixed with water, relatively large shells of Sodium Bentonite are converted into colloidal particles, releasing electrical energy stored in the crystal lattice. These layers then swell about 15 to 30 times their original volume. They then swell about 15 to 30 times their original volume. This causes the Bentonite to cover the well wall and prevent waste on drilling fluids. It also prevents the wall from falling and lubricating and moving the drill smoothly. Bentonite

Types of Bentonite

Bentonite is generally divided into two categories:

Swollen Bentonite or Sodium Bentonite

It absorbs water several times of its volume and expands and becomes sticky. This type of Bentonite is used as drilling Bentonite and also as a slurry for sealing walls. Sodium Bentonite is commonly used in the production of drilling mud and in the preparation of livestock and poultry feed.

Non-swollen Bentonite or Calcium Bentonite

In different industries, Sodium Bentonite is mostly used, because it has a higher swelling capability due to the greater distance between the layers. Calcium Bentonite can be converted to Sodium Bentonite by converting calcium cation to sodium. Calcium Bentonite is used in foundry, absorb oil and grease, to filter and refine. Active Bentonite refers to soils that are changed by a chemical. Activation of Bentonite is mostly done by using saline solution to replace calcium ions with sodium, which increases the swelling property of Bentonite.

Extraction and production process of Bentonite

After extraction, Bentonite is divided into smaller pieces. In this process, water and volatiles are reduced to less than 10%. Then they turn it into soil using a mill and dryer. Another method of producing Bentonite is the use of inorganic acids. These acids dissolve impurities. The result of this dissolution operation is the opening of Bentonite sheets, increasing the diameter of open pores and

نکات ایمنی

Bentonite is not hazard for the environment. But for safety, workers must use personal protective equipment such as masks, goggles, gloves and work clothes when working with this material. It is recommended that the packaging of this compound be stored in a cool, dry place, preferably with proper ventilation. Keep bags containing this mineral completely closed. Storage bags should also be kept away from heat sources. Bentonite is non-flammable, but in the event of a fire in the storage area, it emits ash and carbon dioxide gases that cause suffocation and poisoning. Note that long time presence in areas with high levels of Bentonite dust can irritate the respiratory system. For more information please refer to Bentonite Material Safety Datasheet