Thermodynamic Comparison of Fayalite Formation in Low-Grade DRI under CO, CO–H2, and H2-based Reduction Environments

Fayalite formation during the direct reduction of high-silica low-grade iron ores can be detrimental to the degree of iron metallization and process operations. In this paper, the thermodynamics of fayalite formation in CO/CO 2 , CO–H 2 , and H 2 /H 2 O high-silica iron ore direct reduction processes are discussed, and the comparative thermodynamic stability of iron oxide reduction to fayalite (Fe 2 SiO 4 ) formation is shown on a single diagram. The authors are not aware of any diagram showing this comparison being presented previously in the literature and believe this diagram is very useful for scientists and engineers developing new hydrogen direct reduced iron (DRI) processes.