The Production Process of Bentonite

The production process of bentonite involves several steps, each of which is carefully designed to ensure the quality of the final product.
In the chemical industry, bentonite is widely used as a thickener, emulsifier, and stabilizer in various applications.

Step 1: Mining and Milling
The first step in the production process of bentonite is the mining of the raw material.
Bentonite is typically found in sedimentary rocks and is mined through open-cast or underground mining methods.
After the raw material is extracted, it is transported to the processing plant, where it is crushed and milled to the desired particle size.

Step 2: Washing and Screening
Once the raw material has been milled, it is washed to remove any impurities, such as soil, sand, and other minerals.
The washing process is followed by screening, which involves separating the grains into different sizes.
The grains that are smaller than the desired size are returned to the mill for further grinding, while the larger grains are used in the next step of the process.

Step 3: Purification and De-gelling
The purified bentonite is then subjected to a purification process, which involves removing any remaining impurities and aggregates.
This process also involves the removal of any adsorbed water, which helps to prevent the formation of gel during the drying process.
After purification, the bentonite is de-gelled using a strong acid, such as hydrochloric acid.
This helps to destroy any existing gels and to prevent the formation of new gels during the drying process.

Step 4: Drying and Calcination
After the purification and de-gelling process, the bentonite is dried to remove any residual moisture.
The drying process is usually carried out in a rotary dryer or a fluidized bed dryer.
Once the bentonite is dry, it is calcined to remove any organic impurities and to activate the mineral.
The calcination process is typically carried out in a kiln at a high temperature, such as 500-900°C.

Step 5: Grinding and Classifying
The calcined bentonite is then ground to the desired particle size using a ball mill or a roller mill.
The ground bentonite is then classified to separate it into different sizes, based on its particle size distribution.
The classification process involves using a screen with different mesh sizes to separate the grains into different sizes.

Step 6: Dispersion
To ensure that the bentonite particles are properly dispersed, the ground and classified bentonite is mixed with a small amount of water.
The mixture is then subjected to high-speed dispersion, which involves using a Ball Mill or a Dispersator to reduce the particle size and improve the dispersion.

Step 7: Aging
The dispersed bentonite is then aged for a period, typically several hours or days, to allow the particles to settle and to form a stable gel.
The aging process can be carried out in a static or a dynamic conditions.

Step 8: Granulation
Once the bentonite has been aged, it is granulated using a rolling drum granulator or a fluidized bed granulator.
The granulation process involves rolling the bentonite particles between two rollers, which forces the particles to adhere to each other and form granules.
The size of the granules can be controlled by adjusting the speed of the rollers.

Step 9: Drying and Sieving
After the granulation process, the granules are dried to remove any residual moisture.
The drying process is carried out in a fluidized bed dryer or a rotary dryer.
Once the granules are dry, they are sieved to separate them into different sizes.

Step 10: Packaging
Finally, the bentonite granules are packaged in different sizes and types of containers, depending on the application and the customer's requirements.