COREX®-gas based MIDREX® Direct Reduction plant at JSW in Toranagallu, India

JSW Steel set out to sustainably increase iron production to meet India’s growing demand, while maintaining leading environmental standards. Historically, export gas from two COREX® C-2000 modules, each with a nominal capacity of approximately 800,000 tons of hot metal per year, was used mainly for power generation. The objective was to repurpose this valuable gas for direct reduction, enabling the production of additional iron. The project required innovative engineering solutions and precise management of complex processes to convert both COREX® export gas and coke oven gas into a valuable energy source. This approach ensured high metallization levels and operational efficiency, even in an isolated area with limited fuel availability.

The solution entailed a comprehensive approach to utilizing COREX® export gas for direct reduction. This involved cleaning, compressing, and treating the gas in a pressure swing absorption system to remove CO₂, followed by heating in two stages to achieve the desired reducing gas temperature. The heated gas, with a temperature of approximately 800°C, is introduced into the reduction shaft furnace and flows counter-currently to the descending iron oxide material. The plant is equipped with a transport system that conveys hot direct reduced iron (HDRI) to the adjacent electric arc furnace (EAF), improving energy efficiency and productivity. The project’s scope included the supply of key equipment, electric and automation systems, supervision of erection, commissioning, start-up, and training services, ensuring a seamless integration of new technologies and processes.

The COREX® gas-based MIDREX® direct reduction plant has delivered significant operational improvements. The plant achieved a high metallization level of 92-94%, with a nominal capacity of 147 tons of direct reduced iron per hour. The hot DRI transport system increased productivity by 15-20% and reduced power consumption by 130-150 kWh per ton of liquid steel in the subsequent electric arc furnace (EAF). Electrode savings reached 0.5-0.6 kilograms per ton of liquid steel, underscoring cost efficiency.