Effect of Al₂O₃ and CaF₂ on Melting Temperature of High Calcium Ladle Desulfurization Slag

Abstract

The external desulphurization of molten iron has become an important step in the production of steel and iron. The melting temperatures of high calcium desulfurization slag, which were taken from Shougang Shuicheng Iron and Steel (Group) Co. Limited, were investigated on basis of the method of hemisphaerium temperature. The contents of CaO, Al2O3 and CaF2 in the slag were adjusted in 47%-53%, 14%-20% and 2%-10% respectively by adding analytical reagent Ca (OH)2, Al2O3 and CaF2 using orthogonal design. The results show that the melting temperature of desulfurization slag decreases obviously with the increase of the content of Al2O3 between 14% and 20%, and decreased markedly with the increase of the content of CaF2 lower than 8%. The impact to the melting temperature of the high calcium slag is as follows: Al2O3 > CaF2 > CaO.

Desulphurization Kinetic Prediction into a Steel Ladle by Coupling Thermodynamic Correlations, Fluidynamics and Heat Transfer

“…1,3) Desulfurization is one of the most important operations during the secondary refining process of steel, in practice it is common to use synthetic slag based on CaO and stirring with argon gas in the ladle furnace to improve the reaction kinetics at the interface steel-slag. However, the desulfurization mechanism is complex and depends on several operational variables involved in the process, such as the chemical composition of the slag, [4][5][6] injected gas flow, 7,8) temperature, 9) thickness of the slag layer, 10) refractory lining 11) and the content of dissolved oxygen in the steel. 12) In recent years, Computational Fluid Dynamics (CFD) coupled with kinetic models has been an alternative tool to analyze the behavior of desulfurization in a faster, cheaper and less hazardous way.…”