Bentonite processing and purification technology

Bentonite is one of the earliest and most widely used non-metallic minerals and has high economic value. Modification and activation (nanomethylation, lithiation, acid treatment, etc.) are usually required before industrial application, which is why we need bentonite processing plants.

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

Bentonite production process

In bentonite processing plants, bentonite production mainly uses natural bentonite as raw material, and uses purification, modification, activation, modification and other technologies to obtain corresponding products that meet the requirements. This mainly involves purification and modification.

Bentonite processing plant

Bentonite raw ore generally appears in irregular blocks after mining, with a moisture content of about 25% to 28%. First, it is dried in the stockyard to remove part of the surface water, and then crushed to a particle size of 3~5cm with a crusher (depending on different processes), and then water and sodium are added (activated through a mixer and sodium machine). After extrusion, it is sent to a rotary dryer for drying. The discharged particle size is 2~3cm, the moisture content is 12%~18%, and then it is fed into the mill for grinding. The powdered bentonite clay is then put into a packaging machine for packaging.

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. Therefore, the content of montmorillonite is generally only 50%-80%, but the content of montmorillonite is required in production. More than 90% of bentonite, and these non-clay minerals will adversely affect its performance, so the purification of bentonite is particularly important and a necessary prerequisite for production.

The main purification methods used are dry purification and wet purification:

Dry purification is widely used and is mostly suitable for higher-grade ores with higher montmorillonite content (80%).

The specific purification process is:

(1) Naturally dry the raw bentonite ore to reduce the moisture content to less than 25%;

(2) At this time, the moisture content still does not meet the requirements and has a certain viscosity. 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 keep the moisture content at about 6% to 12%, and then screen it. Drop particles above 10mm;

(3) After crushing and drying, the bentonite particles are crushed, classified and impurity removed again by a classifier:

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

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

Wet purification is suitable for low- to medium-grade bentonite ores with low montmorillonite content, about 30% to 80%.

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