Ferrous metallurgy - Away from carbon

Iron making has taken a route of increased carbon in hot metal from the days when melting iron with low carbon was difficult. In this route, there is evolution of blast furnace technology, which requires good quality of metallurgical coke not available indigenously in India. The steel making technology involves oxidation of high carbon in hot metal to the level desired in presence of foamy slag through oxygen blowing technique and it has made a virtue of high carbon content in the charged hot metal in steel reactor. As a result of use of carbon for reduction as well as heating, India emits 2.8 t of CO2 /t of steel while the global average is 1.7t. of CO2 /t of steel. The search for alternate route for iron and steel making is a compulsion and major steel producers of the world are working for it. Two major trends of using nuclear energy for heating and hydrogen as alternate reducing agent are clearly discernible. In ferrous alloys there is a trend to go away from use of carbon as alloying element. Indian steel producers may explore use of solar energy along with hydrogen/ cracked bio-gas reduction as a future route for iron making. Starting from carbon free iron, steel making will no longer involve oxidation of carbon but will be merely alloying with elements including carbon.