Isothermal Reduction of Wustite Under Hydrogen Atmosphere at 1673 K–1773 K

The use of hydrogen for smelting reduction ironmaking can effectively reduce the consumption of coke, as well as the CO2 emission. However, the dynamic mechanism of this process is not clear. In this paper, isothermal thermogravimetric analysis (TGA) was used to study the reduction process of wustite by hydrogen at 1673–1773 K. Results show that wustite can be entirely reduced, and with the increase in temperature, the reduction reaction becomes more intense, and the time required for the entire reduction decreases. The hydrogen reduction of wustite at 1673–1773 K fits the Mampel power model: f(α) = 2α1/2. When the reactants are molten and the products are solid, the apparent activation energy of the reduction process calculated by the iso-conversional method is 9.15 kJ·mol−1. Molecular dynamics simulation results show that the adsorption of hydrogen molecule on FeO surface is spontaneous. With the increase in temperature, FeO substrate becomes more active, and hydrogen molecules move more violently. The average distance between a certain hydrogen atom and its neighboring atom was analyzed statistically. The increase in temperature will increase the average bond length of hydrogen molecules, reduce their bond energy, and facilitate the adsorption of hydrogen molecules on the FeO surface.