Iron is a base metal extracted from iron ore. Pure iron has melting point of 1530 Degree Centigrade and density of 7.86 gm/cc.
IRON MAKING:
Iron making is the process of Reduction of iron ore using the relevant reducing agent (Reductant).
HOT METAL (LIQUID IRON):
It is the hot, liquid, metallic iron product obtained upon reduction of iron ore (normally in Blast Furnace or in Corex Furnace). It contains about 93-94% Iron (Fe) and other elements/impurities like Carbon (4%), Silicon (~1%), Manganese (+1%) Sulphur, Phosphorus etc. Hot metal is the primary input for production of steel in the Integrated Steel Plants.
PIG IRON:
A product in solid (lumpy) form obtained upon solidification of Hot Metal in Pig Casting Machine. It is called Pig or Pig Iron because of its typical humpy shape. It is produced in 2 broad categories/grades:
Foundry Grade Pig Iron: Pig iron used in the Foundries for production of Cast Iron (CI) Castings using Cupola Furnace. This is the major use of pig iron.
Basic/ Steel Making Grade Pig Iron: Pig iron (including hot metal) used for production of Steel.
SPONGE IRON/ DIRECT REDUCED IRON (DRI)/ HOT BRIQUETTED IRON (HBI) :
Direct Reduced Iron (DRI): Solid metallic iron product obtained upon Direct Reduction of high grade iron ore in solid state itself without being converted into liquid form like that in Blast Furnace.
Sponge Iron (SI): DRI is also known as Sponge Iron because of its spongy micro structure.
Hot Briquetted Iron (HBI) : At times the DRI/SI coming out from the furnace is converted into a bigger compact mass i.e. Briquettes for ease in transportation/charging in steel making furnace, which are known as Hot Briquetted Iron (HBI).
SI/ DRI/HBI is produced by reducing high quality iron ore lumps or iron ore pellets with the help of non-coking coal in Rotary Kiln (in Coal based Plants) or with the help of Natural Gas in Shaft Furnace (known as Gas based plants).
SI/ DRI/HBI is primarily used for production of steel (as a substitute of steel melting scrap), in the Electric Furnaces like the Electric Arc Furnace (EAF) or the Induction Furnace (EIF). However, TISCO is using it in their blast furnace as substitute for iron ore or/sinter
