|Cite this article as:|
|Xudong Mao, Pritesh Garg, Xiaojun Hu, Yuan Li, Samik Nag, Saurabh Kundu, and Jianliang Zhang, Kinetic mechanism analysis of iron ore powder reaction with hydrogen-carbon monoxide, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2512-6|
The powder of iron ore was isothermally reduced at 1023 K-1373 K with hydrogen-carbon monoxide gas mixture (from 0%H2-100%CO to 100%H2-0%CO). Results indicate that the whole reduction process could be divided into two parts that proceed in series. The first part represents a double-step reduction reaction (Fe2O3→ Fe3O4→FeO), for which the kinetic condition is more feasible compared to the second part representing a single-step reduction reaction (FeO→Fe). The influence of hydrogen partial pressure on reduction rate gradually increases as the reaction proceeds. The average reduction rate of hematite ore with pure hydrogen is about 3 times and 4 times higher than that with pure carbon monoxide at 1173 K and 1373 K, respectively. Besides, the logarithm of the average rate is linear to the composition of the gas mixture. Hydrogen can prominently promote the carbon deposition reaction at 1023 K, which improves up to about 30%. The apparent activation energy of the reduction stage increases from about 35 to 45.4 kJ/mol with the increase of hydrogen content from 20% to 100%, which reveals the probable rate controlling step at this stage is combined gas diffusion and interfacial chemical reaction.