Experimental research on mechanism and process of direct iron making reduction of mechanically milling scale with coal

This study delved into the fundamental mechanisms of a mill scale reduction. To achieve this objective, the DRI process was applied to facilitate the mechanical milling of coal-scale mixtures. Temperatures of 700–1000 °C were used to sinter the mechanically milled coal-scale mixtures. The powders were subjected to scanning electron microscopy (SEM) and X-ray diffraction (XRD). In order to identify the reduction of milled scale-coal mixture with the temperature, iron phase analytical techniques and the XRD were used. The differential thermal analysis (DTA) technique was used to determine the measurements of the thermal property. Based on the findings of the experiments, it was concluded that coal devolatilisation and scale reduction forms concurrently when the mixture is being heated. By 40 h milling, the milled coal-scale mixture's reduction start temperature decreased to 750 °C. - Highlights: • This work is to investigate the effect of MM on coal-scale reactions temperatures during heating. • The H₂ and CO were used to reduce Fe₃O₄ which lead to the formation of FeO. • Nucleation rate and growth rate of α-iron increased with MM time. • Activation energy of the reduction reaction decreased by MM up to 40 h MM.