Effect of oxygen-enriched concentration on heat-mass transfer in an industrial-scale smelting reduction vessel

Assessing the impact of oxygen enrichment in the smelt reduction vessel is crucial, as improving heat and mass transfer efficiency is essential for optimizing production. A three-dimensional mathematical model employing a coupled Lagrangian and Eulerian approach has been developed to simulate key processes, including reduction reactions of ore powder, devolatilization of pulverized coal, post-combustion, and other reactions across three zones. The predicted results align closely with actual production data, confirming the model’s reliability and predictive accuracy. The effects of various oxygen concentrations (35 %, 50 %, 75 %, and 100 %) on critical parameters such as concentration of flue gas, temperature of flue gas, post-combustion ratio, production rate of pig iron, and coal rate were examined. Increasing the oxygen concentration led to an expansion of oxygen volume at the lance outlet by factors of 1.15, 2.46, and 2.51, compared to the baseline 35 % oxygen concentration. The post-combustion ratio notably increased from 0.576 to 0.596, 0.636, and 0.674, respectively. Under oxygen-only conditions, the average post-combustion core temperature rose by 11.1 %, reaching 2280.71 K, indirectly reducing coal consumption by 0.33 t per ton of hot metal (0.33 t/tHM). Elevated oxygen concentrations enhanced heat and mass transfer, as well as production metrics.