A mathematical model was developed to quantify the effects of different ope
rational parameters on the nitrogen content of steel produced during oxygen
steelmaking. The model predicts nitrogen removal by the CO produced during
decarburization and how the final nitrogen content is affected by differen
t process variables. These variables include the type of coolants used (scr
ap, direct reduced iron (DRI), etc.), the sulfur content of the metal, comb
ined gas blowing practices, and the nitrogen content in the hot metal, scra
p and oxygen blown. The model is a mixed control model that incorporates ma
ss transfer and chemical kinetics. It requires a single parameter that refl
ects the surface area and mass-transfer coefficient that is determined from
the rate of decarburization. The model also computes the rate of decarburi
zation and the change in surface active elements, such as sulfur and oxygen
, that affect the rate of the nitrogen reaction. Nitrogenization of steel i
n the converter is also predicted with the model. The computed results are
in good agreement with plant data and observations.