Reaction Characteristics Between Sinter and Serpentine

Abstract

In recent years, adding an appropriate amount of serpentine into a blast furnace (BF) is considered to be a popular countermeasure to cope with the usage of iron ores with high Al₂O₃ content; this is because MgO in serpentine can improve the fluidity and desulphurization ability of BF slag with high Al₂O₃. Aimed to better understand the reaction characteristics between sinter and serpentine, a series of experiments were carried out between 1100 °C and 1300 °C under air atmosphere with a sinter to serpentine ratio between 100:1 and 100:6. The results indicated that higher temperatures and greater serpentine additions led to increased magnesioferrite formation. Samples with a sinter-to-serpentine ratio of 100:1 exposed to temperatures below 1300 °C did not have sufficient activation energy for diffusion to occur between the sinter and serpentine under the conditions to form magnesioferrite. But at 1300 °C, large amounts of magnesioferrite and silicate phases could be observed, and the major phases are magnesioferrite phase. At higher serpentine additions, where the sinter-to-serpentine ratio exceeded 100:3, the magnesioferrite reaction could be completed after reaching 1200 °C. Also, the serpentine first reacted with hematite followed by the reaction with SFCA (Silico-Ferrite of Calcium and Aluminum). The SiO₂ in the serpentine formed silicate phases with CaO/Fe₂O₃ in the sinter. The findings from this work may provide guidelines for adding serpentine into BF and improve the operational performances of BF.