Phase Composition and Properties Distribution of Residual Iron in a Dissected Blast Furnace Hearth

摘要

Dissection research is the most meaningful way to understand the internal conditions of blast furnace. Because it can obtain samples from hearth after a blast furnace was shut down. In this paper, a 2200 m~(3) commercial blast furnace was shut down with residual iron remained inside. And then core drilling method was used to obtain a horizontal sample of residual iron, which was located 1610 mm below the centerline of taphole and had a length of 1840 mm. A variety of techniques, such as scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Optical Microscope, X-ray diffraction (XRD) and Raman spectroscopy were applied to analysis the microscopic morphology, phase composition and properties distribution of residual iron samples at different position. The results show that complex phases appear near the cold side, including Fe, C, Ti_(3)N_(2), KAlSi_(2)O_(6) and Al_(2)O_(3). And distribution of properties along the core sample from inside to cold side like density, degree of graphitization and thermal diffusion also have a big change. These results are considered to be related to the function of cooling system.