In the ironmaking industry, iron ore pelletizing and sintered ore production are two fundamental agglomeration processes used to transform fine iron ore into furnace-ready feedstock. Both are essential, but understanding their differences can help steel producers optimize performance, reduce costs, and meet stricter environmental regulations.
So, which is better suited for your blast furnace? In this article, we'll clarify the difference between iron ore pellets and sintered ore, compare their raw materials, and highlight the top 7 advantages of pelletizing over sintering.
What is Iron Ore Pellet?
Iron ore pelletizing is the process of agglomerating finely ground iron ore particles into spherical pellets, typically 8–16 mm in diameter. These pellets are formed using binders such as bentonite or organic binders, then thermally hardened in induration furnaces (e.g., rotary kilns or straight grate kilns).
Iron ore pellets are known for their high iron content, uniform size, and strong mechanical strength, making them ideal for use in blast furnaces and direct reduction processes.
What is Sintered Ore?
Sintered ore is produced by heating a mixture of iron ore fines, fluxes (like limestone), coke breeze (solid fuel), and return fines (recycled sinter) on a sintering machine. The high temperature causes partial fusion of the mix, creating porous, irregularly shaped lumps known as sinter.
Sinter is typically used in blast furnaces and is favored for its higher porosity, but it often contains more impurities and lower Fe content than pellets.
Pelletizing vs. Sintering: What are the Differences?
To better understand the advantages of pelletizing, let's explore how iron ore pelletizing and sintering differ across the full production and application cycle:
Raw Material:
Iron Ore Pelletizing
Pelletizing uses high-grade iron ore fines (Fe content >60%-70%) that undergo beneficiation and are finely ground — over 85% of particles are smaller than 0.074 mm (200mesh).
Typical raw materials include:
- High-grade iron ore fines
- Binders: organic binders, or composite binders, bentonite, molasses and lime...
- Water
Pellet quality is highly sensitive to raw material consistency, binder dosage, and moisture control.
Sintered Ore Production
Sintering allows for more flexible raw material selection.
Typical raw materials include:
- Iron ore fines
- Coke breeze (fuel)
- Fluxes: limestone, quicklime, dolomite
- Return fines (recycled material)
- Water
The sintering process is less sensitive to material purity but generates higher pollutant emissions due to on-bed combustion.
Production Process
Pelletizing: Involves moistening iron ore fines (add water), adding binders, rolling them into green pellets using disk granulator, and then hardening them through controlled induration.
Machines in Pelletizing
Sintering: Sintered ore is produced through a sintering process in which fine iron ore particles are mixed with fluxes, along with other additives. The mixture is then heated to a temperature below the melting point of iron, causing the particles to partially fuse together. This process forms a porous, solid mass known as sinter.
Performance
Iron ore pellets have a more uniform size and shape, along with higher mechanical strength and bulk density. These features make pellets better suited for long-distance transportation and for use in direct reduction processes.
Sintered ore is characterized by its porous structure, which allows for smoother gas flow within the blast furnace. While sinter generally has lower mechanical strength compared to pellets, it offers the advantage of lower production costs.
Applications
Iron Ore Pellets: Iron ore pellets can be used in both blast furnaces and direct reduction iron(DRI) processes.
Sintered Ore: Sintered ore is primarily used in blast furnace operations.
Additives
Jianjie Organic Binder for Pelletizing
During the pelletizing process, various binders are used, including bentonite, organic binders, and composite binders:
- Bentonite: enhances green pellet strength and improves thermal stability.
- Organic/composite binders: provide alternative bonding properties, often reducing impurities, but may not be able to resist high temperature.
Binder selection and dosage impact pellet quality and metallurgical performance, while factors like mixing uniformity also affect production.
Sintered ore relies on fluxes like lime and quicklime to create a liquid phase that bonds ore particles together, enhancing strength.
In sintering, lime, dolomite, and quicklime act as fluxes:
- Fluxes adjust the sinter's alkalinity, reducing the need for additional fluxes in blast furnace smelting, thus enhancing furnace efficiency.
Comparison Table: Pelletizing vs Sintering
Iron Ore Pellet | Factors | Sintered Ore |
High-grade (60-70% Fe) | Ore Quality | Medium to low-grade (50–70% Fe) |
Ultra-fine (<0.074 mm), Blaine number (1500-1800cm2/g) | Particle Size | Coarser (~0.8 mm) |
Bentonite, organic binders | Binder | None (bonding via flux reactions) |
Optional (e.g., limestone, dolomite) | Additives | Fluxes mandatory (lime, dolomite, return fines) |
Spherical, uniform pellets | Final Product Shape | Irregular, porous sinter lumps |
Lower emissions, cleaner process | Environmental Impact | High SO₂, NOx, and dust emissions |
7 Advantages of Iron Ore Pelletizing Over Sintering
Pelletizing and sintering serve different needs (e.g. budget), but pelletizing offers several clear advantages—especially for producers focused on quality, efficiency, and sustainability.
1. Higher Blast Furnace Productivity
Iron ore pellets have a uniform size and shape, which improves bed permeability and airflow in the blast furnace. This leads to faster reduction, better gas distribution, and higher overall productivity.
2. Superior Product Quality
Pellets are produced from high-purity iron ore fines and go through tightly controlled processing steps. As a result, they contain fewer impurities and have more consistent metallurgical properties than sintered ore.
3. Higher Reducibility
Pellets exhibit better reducibility compared to sintered ore , meaning iron can be extracted more efficiently during smelting — reducing energy usage and time.
4. Higher Iron Content
Iron ore pellets typically contain 60-70% iron content. Higher iron content translates directly into higher steel yields and lower slag generation.
5. Stronger Mechanical Strength
Iron ore pellets have high compression strength (CCS up to 2500N per pellet), minimizing fines generation during transport and handling. This ensures smoother furnace operation and reduces material loss.
6. Improved Fuel Efficiency
The high mechanical strength and optimized size of pellets reduce the need for excessive coke usage in the furnace, leading to lower fuel costs and energy savings.
7. Lower Environmental Impact
Pelletizing will generate less pollution, significantly reducing SO₂, NOx, and particulate emissions. This makes it a cleaner alternative to sintering in meeting global emission targets.
Why Choose Jianjie Binder for Pelletizing?
To fully realize the advantages of pelletizing, selecting the right binder is critical. Jianjie's proprietary binder solutions are specifically developed to enhance the efficiency, strength, and purity of iron ore pellets — while reducing operational costs.
✅ 1. Low Dosage, High Efficiency
✅ 2. Helps Increase Iron Content
✅ 3. High-Temperature Resistance
✅ 4. Reduces Bentonite Use
✅ 5. High Viscosity for Better Binding
Summary
Both pelletizing and sintering are essential to iron ore agglomeration, but the advantages of pelletizing are clear: higher productivity, better product quality, greater fuel efficiency, and lower environmental impact.
By choosing high-performance binders and optimizing your pelletizing process, you can unlock more value from your iron ore resources.
Take Your Pelletizing to the Next Level!
By combining the advantages of pelletizing with a high-performance binder like Jianjie, ironmakers can achieve better product quality, lower emissions, and more competitive costs.
Contact Jianjie now to request technical data, samples, or a custom binder formulation for your plant.
Post time: Jun - 12 - 2025
