Items You Must Know About Bentonite Processing Plant

Bentonite is one of the earliest and most widely used nonmetallic minerals with high economic value. It usually needs to be modified and activated before industrial application (Nanomethylation, lithium-based, acid treatment, etc.), which is why we need bentonite processing plant.

Grind bentonite to a certain fineness and retain a certain amount of interlayer water, it will have special properties such as plasticity, adhesion, suspension, adsorption, decolorization, etc., and can be widely used in casting, iron ore, drilling, food, building materials, agriculture, animal husbandry, textile, paper, paint and other industries.

Production process of bentonite

In bentonite processing plant, the production of bentonite mainly takes natural bentonite as raw material, and obtains corresponding products that meet the requirements by using purification, modification, activation, modification and other technologies. Here, purification and modification are mainly involved.

And here is the technological process:

Bentonite raw ore is generally in irregular lump shape after mining, and contains about 25%~28% water. First, part of the surface water is removed by drying in the storage yard, and then it is crushed to a particle size of 3~5cm by a crusher (different according to different processes), and then it is added with water and sodium (activated) by a mixer and sodium machine. After extrusion, it is sent to a rotary dryer for drying. The discharge particle size is 2~3cm, and the water content is 12%~18%, then feed into the mill for grinding. And then the powdered bentonite is packaged in the package machine.

Purification of Bentonite

In addition to the main component of montmorillonite, the raw material bentonite is also mixed with a certain amount of quartz, mica, feldspar and other impurity minerals, so the content of montmorillonite is generally only 50%-80%, but the content of montmorillonite required in production is more than 90%, and these non-clay minerals will have an adverse impact on its performance, so the purification of bentonite is particularly important and is a necessary prerequisite for production.

The mainly used methods of purification are dry method and wet method purification:

Dry method purification is widely used, most of which are suitable for higher grade ores with a large amount of montmorillonite (80%).

The specific purification process is:

(1) Dry the bentonite raw ore naturally to reduce the water content to less than 25%;

(2) At this time, the water content still does not meet the requirements and has a certain viscosity, so it is necessary to use a crusher to crush the raw ore to less than 10mm, and then use a rotary dryer to further dry it to make the water content about 6% - 12%, and then screen out the particles above 10mm;

(3) The crushed and dried bentonite particles are crushed, graded and impurity removed again by a classifier:

(4) The treated bentonite is collected by cyclone dust collector and packaged to obtain the product.

With this method, the content of montmorillonite in bentonite can reach more than 99%, and the recovery rate of montmorillonite can reach to 95%.

The wet method purification is applicable to medium-low grade bentonite ores with low montmorillonite content, about 30%~80%.

Wet purification mainly adopts water as the medium, applies external force and uses the density difference between montmorillonite and impurities in bentonite to separate them to achieve the purification effect. Common methods include natural sedimentation, centrifugal separation and chemical treatment.

Modification of bentonite

The modification of bentonite is to change the type of cation exchanged between the layers of montmorillonite by means of ion exchange, so as to improve the physicochemical properties and technological properties of bentonite.

The modification method of bentonite can also be divided into dry method and wet method:

The dry process is to crush the bentonite first, add a certain amount of Na2Co3 to mix and extrude it on the basis of reaching a certain particle size, and then dry and grind it. It can also be placed after Na2CO3 and bentonite are fully mixed for a period of time, and then dry and grind it.

The wet process is to add a certain amount of water to the mixture of bentonite and Na2CO3, and mixing them evenly to make the sodium modification more complete. Sometimes, in order to improve the sodium modification effect, a small amount of additives, such as tannic acid, can be added to the process of sodium modification of bentonite.

5 workshops in the production line

The production line is divided into 5 workshops, namely, the raw material workshop, the sodium modification workshop, the drying workshop, the grinding workshop, and the packaging workshop.

The main equipment of the raw material workshop is crusher, which includes belt conveyor, crusher and belt conveyor with scale. Bentonite raw materials are transported to crusher through belt conveyor for crushing, and then transported to the sodium modification workshop through belt conveyor with scale.

The main equipment of the sodium modification workshop includes a feeder, a mixer, and a mud extruder.

The drying workshop is mainly composed of drying devices, including dryers, hot air stoves, dust collectors, etc. This workshop is mainly to dry the sodium treated strip semi-finished products, which are transported by belt conveyor to the drying machine and then selected for drying by a hot air furnace. Dust collectors can effectively protect the working environment.

The grinding workshop mainly includes elevator, electric vibrator, grinding mill, hammer mill, etc. The dried products will be first transported to the belt conveyor by the bucket elevator and then sent to the grinding mill through the buffer bin. The grinding mill is the main equipment for bentonite powder making, which can grind the dried semi-finished products into powder that meets product requirements.

The packaging workshop mainly consists of elevator, vibrating hopper, gate valve, unloader, packaging machine, belt conveyors, etc. The product is automatically bagged or bulk loaded, and then transported to the warehouse for storage.

Bentonite grinding mill

Generally, the application field of bentonite requires a powder fineness of 200 meshes. To produce 200mesh sized bentonite powder, ZENITH provides LM series vertical roller mill, LUM series ultrafine vertical roller mill, MRN series Pendulum roller mill, MTW series European trapezium mill and MTW series medium-speed grinding mill. Each series of these grinding mills has different models, and can be selected based on specific production needs.

With the expansion of the bentonite industry and the upgrading of application requirements, the traditional small-scale, multi-equipment and extensive processing mode can no longer meet the market demand. Therefore, using new grinding technology and equipment to improve the processing scale and technical level of enterprises has a great potential market.