Slag:

The CaS becomes partition of the slag. The slag is also produced from any remaining Alumina (Al₂O₃), Silica (SiO₂), Magnesia (MgO) or Calcia (CaO) that entered along the iron ore, sinter, pellets or coke. Then the liquid slag trickles by the coke bed to the bottom of the furnace where it floats on top of the liquid iron as it is less dense. Another product of the iron making procedure, additionally to molten iron and slag, is warm dirty gases. These gases exit the top of the blast furnace & proceed through gas cleaning equipment where specific matter is eliminated from the gas and the gas is cooled up. This gas contains a considerable energy value therefore it is burned like a fuel in the "hot blast stoves" which are utilized to preheat the air entering into the blast furnace to become "hot blast". Any gas not burned in the stoves is sent into the boiler house and is utilized to produce steam which turns a turbo blower that produced the compressed air called as "cold blast" that comes to the stoves.

 In review, the blast furnace is a counter-current reactor where gases ascend & solids descend. In this reactor there are many chemical and physical reactions that generate the desired final product that is hot metal. Typical hot metal chemistry follows as:

Iron (Fe) = 93.5 - 95.0%

Silicon (Si) = 0.30 - 0.90%

Sulphur (S) = 0.025 - 0.050%

Manganese (Mn) = 0.55 - 0.75%

Phosphorus (P) = 0.03 - 0.09%

Titanium (Ti) = 0.02 - 0.06%

Carbon (C) = 4.1 - 4.4%