Modeling the Residence Time of Metal Droplets in Slag During BOF Steelmaking

Bernhard Mitas, Ville Valtteri Visuri, Johannes Schenk

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The ejection of metal droplets into slag due to top-blowing is characteristic of the BOF process. The residence time of the metal droplets in the slag plays a significant role in the kinetics of the metal–slag reactions. In this study, the residence time of ejected metal in slag during BOF steelmaking is investigated and various approaches, based on the blowing number theory and mass balances are compared. Previously published blowing number theories are evaluated in comparison with physically based upper and lower boundaries. The results illustrate that only some of the laboratory-scale blowing number correlations apply to industrial blowing conditions. A mathematical model is developed to predict mass fraction return rates and thus the residence time of droplets in the slag emulsion. Combined with a previously published model for ejected droplet size distribution, it is possible to predict dynamic changes in the interfacial area and mass transfer conditions for metal–slag reactions.
Original languageEnglish
Pages (from-to)1938–1953
Number of pages16
JournalMetallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
Issue numberAugust
Publication statusE-pub ahead of print - 17 May 2023

Bibliographical note

Funding Information:
The authors appreciatively acknowledge the funding support of K1-MET GmbH, a metallurgical competence center. The research program of the K1-MET competence center is supported by COMET (Competence Center for Excellent Technologies), the Austrian program for competence centers. COMET is funded by the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation, and Technology, the Federal Ministry for Labour and Economy, the Federal States of Upper Austria, Tyrol, and Styria as well as the Styrian Business Promotion Agency (SFG) and the Standortagentur Tyrol. Furthermore, Upper Austrian Research continuously supports K1-MET. Besides the public funding from COMET, the current research work of K1-MET is partially financed by the participating scientific partner Montanuniversitaet Leoben and the industrial partners Primetals Technologies Austria GmbH, RHI Magnesita GmbH, and voestalpine Stahl GmbH. The work by Assoc. Prof. Visuri was conducted within the framework of the FFS project funded by Business Finland.

Publisher Copyright:© 2023, The Author(s).

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