This monograph presents the concept of a new mathematical model which was
elaborated to simulate the process of argon blowing through lance and steel refining in
ladle furnace. By combining two different models describing main phenomena affecting
the steel refining process, a new universal hybrid model was developed which takes
into account both the process of mixing of metal in the ladle as well as the thermodynamic
description of the reaction occurring in the system. Numerical connection of
mixing processes and thermodynamic model allowed the identification of the main
factors determining the efficiency of the analyzed steel refining processes.
Mixing model has been implemented in the structure of the hybrid model based
on the theory of elementary reactors, which is adapted to conditions of the analyzed
processes. Thermodynamic model, supplementing the basic equations of the mixing
model, was used to determine the local equilibrium boundary layer between the metal
and slag. The combination of these models was made possible by SimuSage software,
which was used to create application named ARGON. Developed program ARGON is
based on the hybrid model and allows the simulation of the argon blowing process
through the top lance and the process of steel refining in ladle furnace in less than
the average time of real processes.
An important feature of the hybrid model is the function of virtual simulations
which can be used to assess the influence of selected technological parameters on
the course of refining steel processes. The paper presents the results of virtual simulations
showing the effect of the initial iron oxide content in the slag on the effectiveness
of the final deoxidation process of steel by aluminum. It also presents the simulation
results of desulfurization of steel in ladle furnace showing the influence of CaO addition
on the final sulfur content in steel and the effect of dissolved oxygen content in
the metal bath on the efficiency of sulfur removal process.
The results of model verification based on data gathered from the research heats
conducted in Krakow Branch of ArcelorMittal and CMC Zawiercie were presented.
The accuracy of model predictions of the final chemical composition of the metal bath
is satisfactory, which indirectly confirms correctness of the hybrid model formulated
in the work. The obtained results allow to conclude that the developed simulation program
can be a valuable tool to help control some steel refining processes.