Regulation of Foamy Slag Composition in All‐Scrap Continuous Charging Electric Arc Furnaces Based on Dynamic Temperature Variations

In all‐scrap continuous charging electric arc furnace (EAFs) steelmaking, stable foamy slag is critical for maximizing energy efficiency. However, the lack of quantitative control over composition changes caused by temperature fluctuations results in elevated energy consumption and carbon emissions. This study investigates the CaO–SiO 2 –MgO–FeO–Al 2 O 3 slag system through high‐temperature experiments and FactSage thermodynamic calculations. Foaming height peaks at 58 mm at an effective viscosity ( η e ) of 0.126 Pa·s. By isolating the individual effects of basicity, (MgO), (FeO), and temperature on η e , a dynamic composition control method that accounts for real‐time bath temperature variations was developed via nonlinear fitting. Basicity is recommended at 1.8–2.0. For temperatures of 1773 K–1873 K and fixed 7.9 wt% (MgO), (FeO) should be maintained between 11.9 wt.% and 22.0 wt%, with the upper temperature bound corresponding to the lower (FeO) limit. FactSage validation yields a comparable (FeO) range (13.0 wt.%−22.8 wt.%), corroborating experimental results. Industrial application demonstrates reductions in electric energy consumption by 11.2 kWh/t and carbon powder consumption by 2.7 kg/t. This study establishes a quantitative framework for stable foamy slag operation, contributing to low‐carbon, high‐efficiency EAF steelmaking.