Influence of an Electromagnetic Field on Direct Reduction of Iron Oxide Using Hydrogen as a Reducing Agent

ENG: This work investigates the effect of electromagnetic fields (EMF) of varying frequencies on the reduction process of iron oxides and industrial iron ore in a hydrogen atmosphere using thermogravimetric analysis. Both extremely low-frequency (50 Hz) and middle-frequency (25 kHz) EMFs were found to increase the reduction degree and accelerate the reduction reaction compared with experiments without EMF. The application of extremely low-frequency EMF did not cause additional thermal heating of investigated samples. However, with middle-frequency EMF, heating of charged material was observed, which was effectively compensated for by the furnace's automatic power regulation. Experiments with industrial iron ore confirmed that EMF application had a positive effect on reduction process even above the Curie temperature, indicating that the effect is not governed by magnetic properties of iron. These findings demonstrate that EMF-assisted hydrogen reduction can enhance reaction kinetics and reduce hydrogen consumption, offering a promising pathway toward more energy-efficient and sustainable steelmaking.