Abstract
Rheological properties of tap-hole materials were characterized by using a capillary rheo-meter method. The materials were extruded through a capillary of a die with different speeds and resistance was measured. The resistance increased with time and kept a maximum value during the material extruding through the capillary. Shear rate and shear stress were calculated from the extrusion speed and the resistance, respectively. From the relation between the shear stress and the shear rate, the tap-hole materials were found to behave as Bingham fluid. On the other hand, injection pressure changes of a tap-hole material with time in a real blast furnace were measured. By comparison of table tests and the injection pressure changes, the materials were estimated to inject into the furnace in the shape of strings, which were diameter of around 80mm and length of around 30m, and heaped up at the free space in the furnace.
