Dynamic Modeling of a Semi‐Continuous Electric Arc Furnace Process with Continuous Hot Direct Reduced Iron Charging and Slag Flushing

This article presents a dynamic process model of a semi‐continuous electric arc furnace (EAF) operation featuring continuous charging of hot direct reduced iron (DRI), continuous flux addition, and slag flushing. Unlike earlier models focusing on batch charging and tapping, the present model incorporates dynamic mass and energy balances with refining reactions (C, P, Si, and Mn), dissolution of scrap and fluxes, and a single stirred‐tank representation of metal and slag phases. Validation against plant data demonstrates good agreement, with above 80% of predicted slag and steel compositions within ±20% and 85% of bath temperature predictions are within ±50 K of industrial values. The model is further applied to assess the influence of raw material quality and operating conditions. Results indicate that low‐gangue DRI enhances dephosphorization efficiency by ≈40% and reduces process time by ≈5%, while high‐purity lime improves phosphorus removal by ≈10%. Improved DRI quality also increases yield by ≈1.5%, whereas lime quality shows a negligible impact. These findings underscore that trends observed in batch operations cannot be directly extrapolated to semi‐continuous processes. The proposed model thus offers a robust tool for process optimization, yield improvement, and dynamic control of modern EAF operation.