A Gibbs Energy Minimization Approach for Modeling of Chemical Reactions in a Basic Oxygen Furnace
- PDF / 2,081,250 Bytes
- 20 Pages / 593.972 x 792 pts Page_size
- 4 Downloads / 223 Views
TRODUCTION
IN modern steelmaking, the decarburization of hot metal is converted into steel primarily in converter processes, such as the basic oxygen furnace (BOF). The BOF process is characterized by a high oxygen supply rate through a supersonic top lance and by the resulting high rate of decarburization. The most common type of such processes is the Linz-Donawitz converter, i.e., the Basic Oxygen Furnace, and its numerous variants. During the BOF process, the carbon content of the metal bath decreases from approximately 4–4.5 to 0.02–1 wt pct, depending on the final carbon target, while the temperature of the metal bath increases from 1473 K to 1573 K (1200 C to 1300 C) to 1873 K to
ARI KRUSKOPF is with the Research Group for Materials Processing and Powder Metallurgy, Department of Chemical and Metallurgical Engineering, Aalto University, PO Box 16200, Vuorimiehentie 2, Espoo, 00076 Aalto, Finland. Contact e-mail: ari.kruskopf@aalto.fi VILLE-VALTTERI VISURI is with the Process Metallurgy Research Unit, University of Oulu, PO Box 4300, 90014 University of Oulu, Finland. Manuscript submitted April 28, 2017.
METALLURGICAL AND MATERIALS TRANSACTIONS B
1973 K (1600 C to 1700 C) due to exothermic oxidation reactions.[1] A. Dynamics of the BOF Process The interaction of the gas jet with metal bath is a complex phenomenon.[2–4] The momentum of the gas jet induces a cavity, which is in continuous oscillating motion. The quasi-steady-state geometry of the cavity surface can be described as a paraboloid of revolution.[5] The behavior of the cavity can be categorized into dimpling, splashing, and penetrating modes.[2] If the shear force at the interface becomes sufficiently large, metal droplets are detached from the edges of the cavity. For a given cavity mode, the amount of metal droplets generated increases as a function of the so-called blowing number, a dimensionless property which describes the ratio of gas jet inertia to surface tension forces of the metal bath.[6,7] The size distribution of the metal droplets can be described using the Rosin-Rammler-Sperling distribution.[8,9] Through their vast interfacial area, the metal droplets play an important role in the decarburization[10] and dephosphorization[11] reactions. A large body of experimental literature[10,12–16] has been dedicated to the kinetics of the BOF process. With
the help of the knowledge obtained, a considerable progress has been made in the mathematical description of individual aspects of the process. Nowadays, the greatly increased computational resources permit both detailed mathematical[17–27] and data-driven models.[28–32] The former type of models aims to account for all the dominating mechanisms and phenomena and to provide insight on the dynamics of the process, while the latter type of models aims to provide accurate predictions based on statistical analysis of measurement information. The main aspects to be covered by the mathematical models are the dynamics of decarburization reaction and the accompanying oxidation reactions of species
Data Loading...
