About Pelletizing Grade Bentonite
Pelletizing grade bentonite is the binder used to turn fine iron ore concentrate into strong, uniform green pellets. Added at a fraction of a percent to moist concentrate before balling, the clay absorbs and controls water, raises plasticity in the balling disc or drum, and builds the wet and dry strength pellets need before they are fired.
Binder performance comes down to water absorption, swell and fineness. A bentonite that absorbs more water per kilogram lets a plant reach target pellet strength at a lower addition rate. That matters, because every extra kilogram of binder adds silica and alumina to the fired pellet. Our pelletizing grade is selected for high plate water absorption and swell index, and ground fine so that it distributes evenly through the concentrate in the mixer.
We test each lot for plate water absorption, swell index, moisture and fineness in our NABL-accredited laboratory. Pellet plant teams can request samples for balling-disc trials, and fineness can be adjusted to suit the mixing and balling equipment in use. Supply in 1 MT and 1.2 MT jumbo bags suits continuous dosing through bins and feeders, while 25 kg and 50 kg bags are available for pilot work. Every shipment carries a batch Certificate of Analysis, so incoming binder can be checked against agreed limits before it reaches the mixer.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| Plate water absorption | ≥ 500 % | ASTM E946 |
| Swell index | ≥ 24 ml/2 g | ASTM D5890 |
| Montmorillonite content (methylene blue) | ≥ 75 % | Internal method |
| Moisture | 8–12 % | Internal method |
| Passing 75 µm | ≥ 90 % | Wet sieve, internal method |
| pH (5 % suspension) | 9.0–10.5 | Internal method |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA. Binder dosage and pellet quality should be confirmed in balling trials with your concentrate.
Key features & benefits
High water absorption
Plate water absorption of typically 500 % or more lets the binder take up and hold moisture in the concentrate, giving balling a steady, controllable water balance.
Strong green and dry pellets
Well-dispersed montmorillonite improves the drop number and compressive strength of green pellets and raises dry strength, so fewer pellets break on conveyors and in the induration furnace feed.
Lower binder addition
An efficient binder reaches target strength at lower dosage, which limits the silica and alumina added to the fired pellet and helps keep iron content up.
Fine, even distribution
With at least 90 % typically passing 75 µm, the bentonite spreads evenly through the concentrate in the mixer, so pellet strength is uniform across the balling circuit.
Applications
Iron ore pellet plants
Binder for blast furnace and direct reduction pellet production on straight-grate and grate-kiln lines, added to filtered concentrate ahead of balling discs or drums to build green pellet strength.
Low-binder pellet operations
Used where plants aim to minimise binder addition to hold down silica and alumina, for example in pellets destined for direct reduction processes where gangue limits are tight.
Fines and residue agglomeration
Also used to bind mill scale, flue dust and other fine metallurgical residues into pellets or briquettes so they can be recycled back into the process.
Usage & handling
- Typical addition is about 0.5–1.0 % of dry concentrate mass; optimise in balling trials against drop number and strength targets.
- Dose through a calibrated feeder into a high-intensity or drum mixer ahead of balling to ensure even distribution.
- Control concentrate moisture closely, since binder demand rises when the filter cake is too wet.
- Keep jumbo bags dry and covered; damp binder lumps and doses unevenly.
Packaging & supply
- 1 MT and 1.2 MT jumbo (FIBC) bags for continuous plant dosing
- 25 kg and 50 kg HDPE or paper bags for trials and smaller lines
- Custom packaging on request
Frequently asked questions
How much bentonite is used in iron ore pelletizing?
Typical additions are around 0.5–1.0 % of dry concentrate mass, but the right figure depends on concentrate fineness, moisture and the pellet quality you target. Plants usually optimise dosage in balling trials, measuring drop number, green and dry compressive strength. We supply samples and typical data so your team can find the lowest effective addition rate.
Why does plate water absorption matter for pelletizing bentonite?
Plate water absorption, measured by ASTM E946, indicates how much water the bentonite can take up and hold. A binder with higher absorption controls moisture in the concentrate more effectively, which improves balling and pellet strength. In practice it is one of the best single indicators of binder efficiency, alongside swell index and active clay content.
Does bentonite binder affect pellet chemistry?
Yes, modestly. Bentonite is an alumino-silicate, so it adds silica and alumina to the fired pellet in proportion to the addition rate. That is why plants try to keep binder dosage as low as possible while still meeting strength targets. A high-absorption binder helps by delivering the required strength at a lower addition, limiting the effect on pellet chemistry.
Can you supply pelletizing bentonite in bulk for continuous dosing?
Yes. Pelletizing grade bentonite is supplied in 1 MT and 1.2 MT jumbo bags suited to bag-discharge stations, bins and feeders, as well as in 25 kg and 50 kg bags for trials. Each shipment comes with a batch Certificate of Analysis, MSDS and Technical Data Sheet. Discuss your monthly volume and discharge equipment with our team for a quote.