Carburization Behavior of Siderite Pellets in CO–CO2–H2 Mixtures

Abstract

Siderite is a complex and refractory iron ore, which is hard to be utilized in iron and steel industry nowadays. For the effective utilization of siderite, a study of the carburization behavior of siderite pellet is carried out to improve the preparation of iron carbide from siderite. Siderite pellets are carburized in CO–CO2–H2 mixtures, and its carburization behaviors are demonstrated by measuring carbon content, phase change, and microstructure under X‐ray diffraction (XRD), scanning electron microscope (SEM), and optical microscopy. The results show that high temperature favors to the reduction of siderite pellets, but it hinders the carburization of siderite pellet. The optimum carburization temperature is at the range of 600–650 °C. At the early stage of carburization, the main reactions are the reduction of iron oxide, while the main reactions are the carburization of metallic iron at the late stage. At the middle stage, reduction and carburization reactions coexist. Carburization of roasted product of siderite pellet ranking from easiest to hardest is as follows: Fe>FeO>Fe2O3>Fe3O4. The study of carburization behavior of siderite pellet demonstrates that preparation of iron carbide from siderite is a feasible way.