Influence of quick lime on pore characteristics of high-temperature zone in iron ore sinter based on XCT technology

Abstract

The pore structure of the bed has an important influence on the heat transfer and permeability characteristics in the iron ore sintering process. In this study, liquid nitrogen was applied to quench the high-temperature zone sinter to reproduce the original porous structure to the maximum extent. The effect of quick lime on pore characteristics of the high-temperature zone in the iron ore sinter was studied. XCT technology was applied to scan the sinter, and the model of solid phase, pore, and closed pore was reconstructed. The equivalent spherical diameter of the pore and its distribution frequency, volume fraction, sphericity, and surface porosity were statistically analyzed. The results indicate that the addition of quick lime increases the permeability of the green bed and shortens the sintering time. Meanwhile, it promotes the flow of the molten liquid phase, resulting in the bubble aggregation more fully. With the increase of the addition of quick lime, the porosity of the sinter decreases gradually. Finally, the pore skeleton model was established, and the pore skeleton parameters were statistically analyzed. With the increase of quick lime, the total pore volume and total pore length, the number of pore segments, branching nodes and terminal nodes all decrease.