Blast furnace - Design and technology

In its long history, the blast furnace has shown great adaptability, and has withstood, for example, the replacement of the initial fuel, charcoal, by coke, then the substitution of 20 to 35% of the latter, fed in large pieces to the blast furnace, by the injection of fuel oil, gas or powdered coal into the tuyeres.

The blast furnace, on the other hand, requires a supply of high-quality coke and sinter (Blast furnace. Theory ), which requires the construction of a coking plant and an agglomeration, resulting in a major investment that necessitates the installation of a large capacity (probably 1 Mt per year) to ensure profitability. What's more, production can only vary in small increments (blast furnace. Operation ), otherwise there is a risk of damaging the blast furnace.