2015 Volume 55 Issue 10 Pages 2098-2104
For the low carbon operation of blast furnace, it is necessary to maintain the gas permeability in the furnace at low coke rate. The pressure drop in the cohesive zone of the blast furnace is significantly high, and the gas permeability of the cohesive zone has an influence on the productivity of the iron-making process. The gas permeability increases as the thickness of the cohesive zone decreases. The present study aimed to decrease the thickness of the cohesive zone by achieving a higher softening temperature and a lower temperature for the dripping of the sinter ore. The softening, melting, and permeation processes of CaO–FeO–SiO2 oxide on a coke bed was investigated. The change in the shape of the oxide tablet, the formation of the liquid droplet, and its permeation into the coke bed were observed with increasing temperature in several CO/CO2 atmospheres. Softening of the oxide was observed at a temperature that was slightly above the solidus temperature. The deformation of the oxide tablets was strongly affected by the liquid phase ratio. Furthermore, there was no relationship between the temperature of permeation and the melting of the oxide tablet. The permeation of the oxide melt into the coke bed is dependent on the wettability between them.