It is composed of clay mineral montmorillonite and is found mainly in the Kutch region of Gujarat, India. It is grit free soft material and lumps color are yellow, green or light brown depending upon surrounding condition at time of formation. This compound has excellent binding ability and possesses excellent property of absorption due to its porous crystal structure. Added to this, is the unique characteristic of swelling to several times to its original volume when placed in water. It is the most resourceful industrial mineral for its varied applications ranging from Iron Ore Pelletization to Foundries, Drilling mud to Civil engineering etc.
Use of Bentonite in Iron Ore Pelletization:
Application of Bentonite has prolonged rapidly with the evolution of IOP industry.
For production of Pellets, we have developed a well formulated grade 'Pellet Binder', which ensures optimum results in terms of excellent binding strength. Pellet Binder is sodium based additive which enriches the binding and the rate of addition to the Pelletization process is as low as 0.8-1.0 % to attain the desired properties.
In addition to this, it is accompanied by a number of appreciative features :
- High Swelling Index
- Fine powder helps in the formation of pellets
- Excellent bonding properties due to high water absorption capacity
- High green strength and consistent thermal properties provides shape and strength to Pallets
- Higher natural percentage of Iron
- Low silica content
- Does not contain fermentable product and is environmentally friendly
Bentonite Manufacturing Process: ( Flow chart option need to be worked)
- Bentonite is usually an open cast mine and can contain an overburden ranging 1-3 meters. The overburden is excavated from the pit using JCB and tractors.
- After the OB is removed, suitable grade of Bentonite is selected and quarried under direct supervision of Mines supervisor.
- It is then transported from pit to drying platform by tractors and then dried in natural state to reduce moisture from 35% to 12%
- During process of drying, Bentonite Lumps start breaking while non clay lumps remain intact. At this point, experienced women workers removes foreign material like gypsum, carbonates etc.
- Depending upon the application, Bentonite is then treated with chemicals like soda ash, STPP and Polymer for achieving the desired parameter.
- For soda ash activation, we use the method of wet activation, which ensures even penetration of soda which ensures better results.
- The lumps are then sun dried by turning over till the desired moisture is achieved.
- The approved activated material is then grinded using a Pulverizer or a Roller Mill to achieve the desired mesh size. // to check the language