Identification of Rate, Extent, and Mechanisms of Hot Metal Resulfurization with CaO-SiO{sub 2}-Na{sub 2}O Slag Systems

Journal Article · Thu Aug 15 00:00:00 EDT 2019 · Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science

DOI:https://doi.org/10.1007/S11663-019-01600-5· OSTI ID:22933537

Vuolio, Tero; Visuri, Ville-Valtteri ^[1]; Paananen, Timo ^[2]; Fabritius, Timo ^[1]

---

1. University of Oulu, Process Metallurgy Research Unit (Finland)
2. SSAB Europe Oy (Finland)

The resulfurization of hot metal has not been comprehensively studied in literature. This study presents an experimental and mathematical modeling study of resulfurization in thermodynamic and kinetic point of view. The rate, extent, and mechanisms of resulfurization were evaluated by analyzing concurrently the physical properties and sulfur-extracting ability of the slag. Experiments were conducted in a chamber furnace in an argon atmosphere, and the hot metal was sampled with pre-defined basis. The experiments were continued until the metal–slag system reached an apparent thermodynamic equilibrium. To obtain a quantitative measure on the effect of system properties on the rate and extent of resulfurization, the results of this study were combined with previous studies handling the sulfide capacities of Na{sub 2}O-SiO{sub 2} and CaO-SiO{sub 2}-Na{sub 2}O slag systems. The sulfide capacities of the slag and corresponding metal–slag sulfur partition ratios were mathematically modeled with data-driven techniques such as multiple linear and non-linear regression and artificial neural networks. Finally, with the help of these, to study the kinetics of resulfurization, a simple mechanistic reaction model was derived. The results suggest that resulfurization of hot metal follows 1st-order kinetics and that the rate and extent can be regulated through the control of the associated thermodynamic driving force and by modifying the physical properties of the slag. The rate-limiting factor was found to be determined by the morphology of the slag phase.

• OSTI ID: 22933537
• Journal Information: Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science, Journal Name: Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science Journal Issue: 4 Vol. 50; ISSN 1073-5615; ISSN MTBSEO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARGON
CALCIUM OXIDES
CHAMBER FURNACES
CONTROLLED ATMOSPHERES
KINETICS
MATHEMATICAL MODELS
METALS
MORPHOLOGY
NEURAL NETWORKS
NONLINEAR PROBLEMS
PHYSICAL PROPERTIES
REGRESSION ANALYSIS
SILICON OXIDES
SLAGS
SODIUM OXIDES
SULFIDES
SULFUR
THERMODYNAMICS