Effect of Al_2O_3, SiO_2 and MgO on the Formation of Calcium Ferrites in Sinter using X-ray Diffraction Method

摘要

In order to elucidate the fundamental aspects of the minerals formation processes during sintering, the Fe_2O_3-CaO-Al_2O_3-SiO_2 system and the effect of MgO on synthesized iron ore sinter were studied by image analysis and X-ray diffraction method. Most existed calcium ferrite was identified to be a solid solution of CaO centre dot 2Fe_2O_3 with a small amount of solubility of Al_2O_3 and SiO_2. With an increase of the content of Al_2O_3 in the system, the amount of calcium ferrite was increased. On the other hand, the amount of calcium ferrite was decreased, and the amount of hematite was increased with increasing the content of SiO_2. Crystal structure of calcium ferrite with Al_2O_3 and SiO_2 was changed from monoclinic to triclinic as well as the unit cell volume shrank with fixing Al_2O_3 and increasing SiO_2. With increasing the content of MgO(1 approx 3 wt percent), the amount of magnetite was increased and hematite was decreased but calcium ferrite was not changed.