Title

EVALUATION OF THE SLAG SYSTEM CaO-MgO-Al2O3-SiO2

EVALUATION OF THE SLAG SYSTEM CaO-MgO-Al2O3-SiO2

Authorship

Bielefeldt, Wagner Viana; Vilela, Antônio Cezar Faria; Heck, Nestor Cezar

Bielefeldt, Wagner Viana

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Vilela, Antônio Cezar Faria

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Heck, Nestor Cezar

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DOI

10.5151/2594-5300-22764

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Abstract

Research on the topic ‘steel slag’ has grown worldwide. In fact, since 2005 the number of articles published per year has nearly doubled. Nevertheless, even the known (pseudo-quaternary) system CaO-MgO-SiO2-Al2O3 presents lack of data regarding the subjects: phases present at the equilibrium state and physicochemical properties. This slag system plays important roles during the secondary refining of steel, such as: protection of refractory, sulfur level adjustment and absorption of non-metallic inclusions. Accordingly, the knowledge of the solid/liquid ratio considering, for instance, binary basicities (CaO/SiO2) and MgO content, is full of significance. And, with respect to slag properties, the importance of viscosity stands out clearly. This property has an influence, for example, in metal-slag reactions and slag-refractory interactions, among others. Consequently, the objectives of this work are: (i) to perform a thermodynamic study of the phases at equilibrium at a high basicity value; and (ii) to evaluate the slag viscosity (from literature data and via thermodynamic software) as a function of the slag composition, establishing therefore a critical analysis with the published data. To achieve the proposed aims, the thermodynamic FactSage v. 6.3 software will be employed.

Research on the topic ‘steel slag’ has grown worldwide. In fact, since 2005 the number of articles published per year has nearly doubled. Nevertheless, even the known (pseudo-quaternary) system CaO-MgO-SiO2-Al2O3 presents lack of data regarding the subjects: phases present at the equilibrium state and physicochemical properties. This slag system plays important roles during the secondary refining of steel, such as: protection of refractory, sulfur level adjustment and absorption of non-metallic inclusions. Accordingly, the knowledge of the solid/liquid ratio considering, for instance, binary basicities (CaO/SiO2) and MgO content, is full of significance. And, with respect to slag properties, the importance of viscosity stands out clearly. This property has an influence, for example, in metal-slag reactions and slag-refractory interactions, among others. Consequently, the objectives of this work are: (i) to perform a thermodynamic study of the phases at equilibrium at a high basicity value; and (ii) to evaluate the slag viscosity (from literature data and via thermodynamic software) as a function of the slag composition, establishing therefore a critical analysis with the published data. To achieve the proposed aims, the thermodynamic FactSage v. 6.3 software will be employed.

Keywords

Slags; Computational thermodynamics; Steelmaking; FactSage.

Slags; Computational thermodynamics; Steelmaking; FactSage.