Decrease of the amount of fluxes such as limestone, quartz, and serpentine in the iron are sintering process contributes to decreasing the amount of slag volume in the blast furnace operation aimed at increasing the pulverized coal injection. Therefore, it is important to use those fluxes effectively in the sintering process.
To clarify the desirable size of fluxes, the assimilation reaction of fluxes with iron oxide in the air has been evaluated quantitatively.
Assimilation ratios of fluxes were evaluated in order, from higher to lower, as limestone, quartz and serpentine. The assimilation ratio of limestone decreased when quartz and serpentine were added to the limestone-Fe2O3 two component system. The assimilation ratio of limestone decreased remarkably when fine serpentine was added to that system. Magnesioferrite ( (Mg, Fe)O·Fe2O3) precipitated around serpentine in the assimilation of serpentine. The assimilation ratio of serpentine was concluded to be lower than that of limestone and quartz based on the assimilation characteristics. The amount of melt decreased because magnesioferrite isolated limestone from the melt when fine serpentine was added.