Ferrochrome Production in a Submerged Electric Arc Furnace: Fundamental Analysis Based upon the FactSage‐Macro Program Approach

Abstract

Around 80% of the FeCr produced worldwide is utilized in stainless steelmaking. Thus, the growth of the stainless‐steel industry is directly related to FeCr production. Although the FeCr production in submerged arc furnace (SAF) is fairly stabilized, new challenges have emerged in the furnace operation due to the depletion of lumpy ores, high SiO2 content, and lower Cr/Fe ratio in the low‐grade ores. In this regard, the addition of various fluxes such as quartz, magnesite, and bauxite are considered to improve the Cr recovery in SAF operation, particularly in the context of low‐grade ores. In this study, thermodynamic calculations are performed to discuss the effect of various additives (MgO in magnesite, Al2O3 as bauxite, and SiO2 in quartz form) on Cr recovery and slag formation temperature. In addition, a comprehensive thermodynamic‐based process model has been developed for FeCr operation that captures the most important thermochemical reactions. The modeling results are compared with the plant data, and suitable modifications in the slag compositions are made to maximize Cr recovery. Moreover, new plant trials are performed with modified slag composition, and its effect on Cr recovery is also discussed.