Kinetic Modeling of Hydrogen‐Based Reduction of Iron Ore under Isothermal and Non‐Isothermal Conditions

A hydrogen‐based reduction (HyDR) kinetic model is developed to simulate the reduction behavior of a single iron ore specimen descending through thermal and gas composition profiles representative of a Midrex‐type shaft furnace. The model incorporates temperature‐dependent kinetics, gas–solid interactions, and sequential phase transformations. Validation with experimental data from the literature shows strong agreement across a wide temperature range, confirming its predictive capability. Simulations are grouped into five isothermal cases (650–1050 °C), ten non‐isothermal scenarios with varying heating profiles and H 2 /H 2 O ratios, and four shaft furnace simulations along a single vertical reduction path at different radial positions to capture cross‐sectional variations in temperature and gas‐composition. Across 650–1050 °C and H 2 fraction from 0.45 to 0.92, higher temperature and H 2 fraction monotonically increase the apparent reduction rate and the reduction extent (from total mass loss), with the wüstite‐to‐Fe step showing the greatest sensitivity. In shaft furnace cases, slower reduction near the center is observed due to lower temperature and hydrogen partial pressure. Although developed at the specimen scale, the model effectively captures the dynamic evolution of reduction behavior and offers a robust tool for analyzing HyDR processes under simplified simulated thermal and gas‐composition conditions, contributing to the advancement of low‐carbon ironmaking.