Effect of slag composition on desulfurization and inclusion modification during ladle furnace refining

School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China

Received: 8 April 2014
Accepted: 19 June 2014

Abstract

The influence of LF refining slag composition on desulfurization and inclusion modification was investigated through industrial experiments and thermodynamic analysis. The results show that the sulfide capacity decreases with the decrease in (%CaO)/(%SiO₂) and (%CaO)/(%Al₂O₃) of the slag. The theoretical sulfur distributions agree well with the analysis results when the sulfide capacity is calculated by Zhang’s model, but the theoretical sulfur distributions are higher than the analysis results when the sulfide capacity is calculated by the KTH model. During the LF refining process, inclusions are transformed from Al₂O₃ inclusions into CaO-MgO-Al₂O₃ system inclusions. Higher slag basicity results in higher CaO and MgO and lower Al₂O₃ content inclusions in molten steel at the end of the LF process.