Modeling of the reduction of iron oxide by methane-conversion products in a plasma jet. II. heat and mass transfer

A mathematical model of reduction of fine-dispersed iron-oxide particles in a high-temperature gas medium on the basis of methane-conversion products has been developed. In the model, allowance is made for the motion of the gas and particles in the flow, particle–gas and gas–reactor wall heat exchange, melting of a solid iron-oxide (FeO) particle in the approximation of a thermal Stefan problem, and for the motion of the FeO/Fe conversion front in an individual particle in the approximation of a diffusion-type Stefan problem. The modeling results have been compared to the available experimental data. Thermophysical conditions for realization of this process, which ensure the reduction of iron oxide to pure iron, have been determined. A possible mechanism of iron oxide-to-iron conversion in a particle has been considered.