Recycling solid waste from steel production, the Rotary Hearth Furnace (RHF) converts these residues into valuable iron products—low-reduced iron (LRI) and direct-reduced iron (DRI)—which are subsequently fed into Blast Furnaces (BF) and Electric Arc Furnaces (EAF), respectively. While the RHF does not directly lower carbon dioxide emissions, its integration into steelmaking operations supports a gradual shift toward the more electrified and less carbon-intensive EAF route over the conventional BF route. Additionally, by reducing landfill dependency and lowering waste treatment expenses, RHF-based recycling offers both environmental and economic benefits. This study develops an integrated modeling framework that captures the complex interconnections of material and energy flows among RHF, BF, and EAF units. The resulting RHF–EAF–BF model enables dynamic simulation of crude steel production under different process configurations and operational constraints. To identify optimal production strategies, a multi-objective optimization is applied, targeting the simultaneous minimization of carbon intensity, energy consumption, and unit production cost. The integrated model not only serves as a robust simulation tool for scenario analysis but also offers practical insights for advancing resource-efficient and low-carbon steelmaking. The results confirm that strategic coordination across the RHF–EAF–BF network can lead to significant improvements in sustainability and cost-effectiveness.
