Article ID: ISIJINT-2024-223
Gas permeability in a blast furnace is maintained via a layered structure comprising iron ore and a coke bed. High temperatures may induce a breakdown of this layered structure, and hence, an understanding of the transition from solid-like deformation to liquid-like deformation is crucial for preventing the breakdown. In this study, the flow behavior analogous to that of a layered structure comprising iron ore and a coke bed with derived melts was examined using polyethylene beads and silicone oil. Oscillation and creep tests were conducted on analogous samples of polyethylene beads and silicone oil with viscosities similar to that of the slag melt. The samples were prepared by mixing at liquid-phase to solid-phase volume ratios of 10/90, 25/75, and 40/60. Air was present in the samples used herein. The transition between the solid-like and liquid-like flow was investigated via oscillation testing, and the flow behavior on long timescales was investigated via creep testing. The results of oscillation testing indicated that a larger strain is required for flow at an intermediate liquid fraction or greater liquid viscosity. The results of creep testing revealed that the sample deformation changes from decelerating to accelerating as the applied stress increases at higher or lower liquid-phase fractions. In contrast, at an intermediate liquid fraction, the sample deformation decelerated at a relatively higher stress. The number of liquid bridges may be the highest at an intermediate liquid fraction, and the force between the particles generated by the liquid bridges is expected to be the most significant.
