3. Evolution of the Martin kiln since 1950 and its disappearance

To understand the evolution of the Martin kiln since 1950, it's important to remember that this process is used in two major families:

• Scrap process, where the load is 70% scrap or more, with the remainder consisting of liquid or solid cast iron;

• operation with a high proportion of liquid cast iron (50-80%), supplemented by scrap; the term ore process derives from the former use of ore as a source of oxygen.

The use of pure oxygen varied from case to case.

• In the high-scrap process, oxygen was mainly used to accelerate heating (oxygen under the burners, supplemented by oxygen lances in the roof or introduced through the furnace doors, to speed up scrap melting