Evaluation of Slag Foaming Behavior Using Renewable Carbon Sources in Electric Arc Furnace-Based Steel Production

This study investigates the influence of various carbon sources, including anthracite, calcined petroleum coke, high-temperature coke, biochar, and a blend of 50 wt.% biochar and 50 wt.% coke, on the foaming behavior of slag during steel production in electric arc furnaces. The slag composition was maintained at FeO-CaO-Al2O3-MgO-SiO2, with foaming studies conducted at 1600 ◦C. Key foaming characteristics such as foam height, foam volume, relative foaming height, and gas fraction were assessed alongside advanced analytical techniques including X-ray diffraction (XRD), chemical analysis, Mossbauer spectroscopy, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) mapping. The results indicated distinct foaming phenomena driven by the type of carbon source used, where biochar alone exhibited inferior foaming characteristics compared to traditional carbon sources. However, when used in a mixture with coke, the foaming behavior improved significantly, achieving comparable characteristics to those of conventional carbon sources. The XRD analysis further revealed compositional differences between the slag foams, emphasizing the potential of renewable carbon sources in enhancing slag foaming behavior in steelmaking processes.