Why does iron ore need to be sintered andor pelletised befor

Why does iron ore need to be sintered and/or pelletised before the blast furnace ironmaking?

Solution

Iron ore fines generated in mines and ore benefication units, in its original form are not suitable for feeding into the blast furnace, so they need to be sintered. After sintering the product is known as sinter, of which the physical- chemical properties can be modified to some extent which suits to the blast furnace operations.

The simple process of sintering- Heating of iron ore fines along with flux and coke fines or coal to produce a semi-molten mass which then solidifies into porous pieces of sinter with the sizes and strength characteristics necessary for feeding into the blast furnace.

It has many advantages, for example the presence of lime in sinter removes the limestone from the burden, thus a lot of energy can be saved which otherwise would be needed for the calcination inside the blas furnace.

The rate of Coke combustion can be controlled by controlling various elements of sinter, such Fe content in Sinter, reduction properties(RI) and fines content.