Toward on-line slag composition analysis:optical emissions from laboratory electric arc

Electric arc furnaces and ladle furnaces have an important role in the future of steelmaking where CO₂ emissions have to be mitigated to an acceptable level. One way to address this goal is to optimize and improve the current practices by adjusting the chemistry and reactions with material additions or gas injections. These procedures would greatly benefit from on-line slag composition analysis. Since the electric arcs radiate throughout the melting, optical emission spectroscopy is a potential method for such analysis. In this study, optical emissions from the electric arc are measured in a laboratory environment. Dozens of atomic emission lines were correlated with Cr₂O₃, Fe₂O₃, Al₂O₃, SiO₂, MnO, MgO, CaO, CaF₂, V₂O₅, and Ni content of the slag together with correlation between CaF₂ and molecular optical emission bands of CaF. Optimal spectral resolution for industrial applications was deducted to be between 0.022 and 0.179 nm.