How to Choose a Binder

Iron ore pelletisation turns fine iron ore concentrate into pellets that can be handled and processed in ironmaking. A binder helps the fine particles form pellets and gives them strength during handling and processing.

Bentonite is widely used as an iron ore pellet binder. Choosing a suitable grade involves more than comparing price or one laboratory specification. Ore characteristics, moisture, mixing and balling conditions all affect pellet performance.

What does bentonite do in iron ore pellets?

When mixed with water and iron ore concentrate, bentonite helps the particles bind together during balling. This supports the formation of green pellets and their strength before induration, the heating process used to harden the pellets.

Bentonite can affect several stages of pellet production, including green pellet formation, handling strength and fired pellet properties. The result depends on the full process, so a grade that performs well with one concentrate may not perform the same way with another.

The main trade-off to consider

Bentonite can improve binding, but it also adds mineral matter to the pellet. Depending on its composition and the plant’s requirements, this may increase silica and alumina in the finished product.

The selection goal is therefore to achieve the required pellet performance while keeping binder addition within the plant’s chemical and operating limits. The lowest price per tonne alone may not reflect the overall value of a binder.

What to check when selecting a bentonite grade

1. Compatibility with the iron ore concentrate

Iron ore concentrates differ in particle size, mineral composition and surface properties. These differences can affect how the concentrate responds to water and binder.

Assess the bentonite using the actual concentrate used at your plant. Avoid selecting a grade based only on a supplier’s general description or a result from a different ore.

2. Chemical composition

Review the supplier’s technical data and certificate of analysis. Pay particular attention to the parameters your plant uses to control pellet chemistry, including silica and alumina.

Confirm that the data refers to the grade being supplied, and discuss any plant-specific limits with your technical team.

3. Moisture and physical consistency

Moisture and physical condition can affect storage, feeding and mixing. Ask the supplier for current product documentation, including the technical data sheet and certificate of analysis. If moisture limits or particle-size requirements are important to your process, include them in the purchase specification.

4. Performance in your balling circuit

Binder performance depends on more than the material itself. Mixing sequence, moisture control, residence time and balling equipment can influence pellet size and strength.

During a trial, keep operating conditions as consistent as possible. Change one factor at a time where practical so the results can be compared.

5. Supply and handling requirements

Confirm the available packaging, order quantity, delivery schedule and storage recommendations before placing a bulk order. Consistent supply and clear documentation matter when the binder is used in a continuous production process.

How to evaluate a binder before making a change

A controlled trial can help determine whether a bentonite grade is suitable for your process. Work with your plant and laboratory teams to agree on the trial conditions and acceptance criteria before testing.

Depending on your operation, you may compare:

• Green pellet drop or impact performance
• Green and dry pellet strength
• Pellet size and balling behaviour
• Binder consumption at the required performance level
• Fired pellet strength and relevant chemical properties

Use the same concentrate and comparable operating conditions when assessing candidate grades. Record the results alongside the binder dosage and process settings. This makes it easier to distinguish a genuine binder improvement from a change caused by moisture or operating conditions.

Questions to ask your bentonite supplier

Before requesting a quotation, prepare the requirements your technical and procurement teams need to assess the product:

• What grade is recommended for iron ore pelletisation?
• Can you provide a current technical data sheet and certificate of analysis?
• What packaging and order quantities are available?
• What are the storage and handling recommendations?
• Can the product be evaluated in a sample or plant trial?

Choosing a binder for your process

The right bentonite for iron ore pelletisation is the grade that meets your plant’s technical requirements under your operating conditions, with reliable documentation and supply. Compare candidates through a controlled trial and assess both pellet performance and the effect on finished-pellet chemistry.

Delta Corp supplies bentonite for iron ore pelletisation. Contact our team at enquiry@deltacorp.com.my to discuss your requirements and request product information.