Carburization degree of iron nugget produced by rapid heating of powderly iron, iron oxide in slag and carbon mixture

Iron nugget making process by rapid heating reduction of powdery iron ore and pulverized coal mixture is regarded as one of the novel iron-making processes. Iron carburization during smelting reduction is especially important reaction step from the viewpoint of saving energy in this process. If the rate and efficiency of carburization reaction are increased, energy consumption of the process will be reduced to large extent. The purpose of this study is to clarify the carburization degree of iron nugget during smelting reduction of the mixture. The sample was prepared from graphite, electrolytic iron powder and synthetic slag containing iron oxide to simulate iron carburization phenomena during smelting reduction of the mixture in the present work. The sample was quenched immediately after the mixture changed into nugget shape in a rapid heating process. Laser microscope combined with infrared image furnace was used for sample heating and observation of carburization phenomena, and carbon content in the nugget was chemically analyzed after quenching. From above-mentioned investigations, it was revealed that the occurrence of carburization during smelting reduction in the sample mixture is advantageous to obtain higher carbon contain iron nugget, novel iron making process, iron carburization, smelting reduction, confocal laser microscope combined with infrared image furnace.