What are Pellets?
Pellets are small spheres of iron ore used for producing steel. They are made with powder (iron ore fines) which is generated during mining of iron ore.
Pellets are made of Iron Ore fines which once were disposed of as waste. These fines are now rolled into ball small balls, and then fired in a kiln to sinter the particles into a hard sphere. Pellets are formed from beneficiated iron ore fines.
Pellets are reduced faster than sinter and iron ore lumps. High porosity also helps in better metallization in DRI units. The Chemical composition is uniform as it gets controlled during beneficiation process. Pellets have high and uniform mechanical strength and can be transported to long distances without breaking.
The ore is ground to a very fine level and mixed with Limestone or dolomite as a fluxing agent & binding agents. If the ore is a Hematite ore, coke coal can be added to the mix to work as an internal fuel to help fire the pellets.
This mixture is blended together in a mixer and fed to balling discs or drums to produce green pellets of size typically about 8-18mm. The green pellets are then fed to the induration machine. Both straight grates and grate kilns dry the pellets out in a drying section, then bring the pellets up to a temperature of about 800-900 °C in a preheat zone, then finish the induration process at roughly 1200-1350 °C. The pellets are then cooled to a suitable temperature for transporting to a load out facility. Both processes recycle the heat from the pellet back through the process to aid in energy efficiency and decrease fuel usage.
Iron Pellets Ranging from 3mm to 20mm