Study on the kinetic mechanism of steel resulfurization by sulfur-bearing slag

Liu, Chunyang; Huang, Fuxiang; Wang, Xinhua; Yang, Guangwei

doi:10.1051/metal/2015021

Cited by 1 publication

(9 citation statements)

References 17 publications

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“…The evolution of the sulfur content in the metal phase is presented in Figure 4. The evolution of sulfur in the metal phase appears to follow 1st-order kinetics, and the reaction seems to reach the equilibrium state relatively fast, which is in agreement with the results given in Liu et al [5] It can also be interpreted from the figure that both the rate and extent of resulfurization are inversely proportional to the Na 2 O content of the slag. For this reason, it is evident that the rate and extent of resulfurization can be regulated by adding alkaline flux on the slag.…”

Section: A Rate Of Resulfurizationsupporting

confidence: 90%

“…The effect of sodium oxide (Na 2 O) on the rate of desulfurization via transitory and permanent phase contact and on the sulfide capacity of the slag has been reported in several studies. [2][3][4][5]10,11,13,30,31] It has been concluded that the sulfide capacities of Na 2 O/SiO 2based slags are higher than those of CaO/SiO 2 -based slags [3,[5][6][7] and the rate of desulfurization increases with the increase of the Na 2 O content in the slag. [2,3] The activity of CaO has been found to be increased with the activity of Na 2 O in the slag phase, [30,32] which can be associated to increased dissolved fraction of CaO.…”

Section: Sulfide Capacity Of the Slag Phasementioning

confidence: 99%

“…The sampling of hot metal was conducted every 5 minutes during the time period of 0 to 20 minutes, and every ten minutes during the rest of the experiment, which makes the total duration of the experiment 90 minutes, which according to various authors is held to be a sufficient time to reach the apparent metal-slag equilibrium state. [2][3][4][5][6]10,11] The sulfide capacity for each of the slag phases was determined with the metal-slag equilibrium method. The compounds used in the preparation of the slag phase with corresponding chemical purities were CaO (99.7 wt pct), CaS (97 wt pct), Na 2 CO 3 (99.9 wt pct), and SiO 2 (99.7 wt pct).…”

Section: A Apparatusmentioning

confidence: 99%

“…Early observations on the resulfurization of hot metal in the case of the CaO-SiO 2 -Na 2 O system were made in the study of Schenck et al [2] The authors conducted experiments on desulfurization in the Fe-C-S system and identified that the changes in the sulfur and iron oxide contents of the slag followed were found to be associated with each other, but the authors did not present the mechanisms behind the resulfurization reaction. [2] Liu et al [5] studied the kinetics of resulfurization of steel in the CaO-FeO-SiO 2 -CaS slag system. In their study, it was established that resulfurization of steel follows 1st-order reaction kinetics, and is controlled by mass transfer in the slag phase.…”

Section: Introductionmentioning

confidence: 99%

“…The authors also suggest that the increased liquid phase fraction in the slag phase could increase the rate of resulfurization due to the increased rate of mass transfer at the interface. [5] However, the authors did not consider the fact that the studied fluxes (FeO and CaF 2 ) both decrease the sulfide capacity according to van Niekerk and Dippenaar [6] and Schenck et al [2] This being so, the rate of resulfurization increases due to the increase in the thermodynamic driving force, which assumedly has a greater effect on the molar flux of sulfur through the metal-slag interface than the increased rate of mass transfer associated to the liquid phase portion. Also in their study, the sulfur content of the slag phase was only 0.12 wt pct, [5] which would imply a low thermodynamic driving force in the case of high carbon and silicon contents in the metal phase.…”

Section: Introductionmentioning

confidence: 99%

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Identification of Rate, Extent, and Mechanisms of Hot Metal Resulfurization with CaO-SiO2-Na2O Slag Systems

Vuolio

Visuri

Paananen

et al. 2019

Metall Mater Trans B

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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 2 O-SiO 2 and CaO-SiO 2-Na 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.

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Section: A Rate Of Resulfurizationsupporting

confidence: 90%