1. Rationale for pretreatment processes for liquid pig iron

1.1 General information on blast furnace treads

• Impurities in the blast furnace

• Due to the presence of excess carbon in the blast furnace, melting is always close to carbon saturation (carbon contents of around 4.5% at temperatures of 1480 to 1500 C).

• The other imurities (manganese, phosphorus, titanium, chromium, niobium and vanadium) mainly depend on their entry into the blast furnace via the ores. Indeed, as blast furnace slags are poorly oxidized and acidic (basicity index CaO/SiO ₂ of the order of 1.2 to 1.4), the partition coefficients of these elements between slag and metal are very favorable to...