Scenario-based optimisation of steel production technologies: A comparative assessment for Mobarakeh Steel Group's capacity enhancement

Abstract

This study proposes a systematic framework for selecting optimal ironmaking technologies to enhance the sustainable production capacity of Mobarakeh Steel Company (MSC) in Isfahan, Iran. Five commercial technologies – Midrex, Corex, Finex, SL/RN, and ITmk3 – were evaluated across nine scenarios with varying shares of scrap, DRI, and hot metal, emphasising low-grade haematite utilisation. A multi-criteria decision-making (MCDM) approach assessed energy use, CO 2 emissions, water consumption, and capital and operating costs. Scenarios were optimised for raw material flexibility, environmental compliance, and a target 6 Mt/year capacity increase. Results show that a mix of 25% scrap and 75% hot metal, using COREX or a hybrid COREX–FINEX/ITmk3 system, is the most favourable, reducing CO 2 emissions by 18%, energy use by 22%, and raw material costs by 30% compared with conventional BF–BOF routes. The findings offer practical guidance for integrated steel plants pursuing sustainable and cost-effective production, especially in regions rich in low-grade iron ores under carbon pricing policies.