Flow and penetration behaviours of liquid phase on iron ore substrate and their effects on bonding strength of sinter

Abstract

The flow and penetration behaviours of the liquid phase on nuclei ore play crucial roles in the bonding of the sinter. In this study, the flow and penetration tests of the liquid phase and simulation tests were conducted to study the effects of SiO₂ and Al₂O₃ contents of the adhering fines on the flow area (FA) and maximum penetration depth (MPD) through the micro-sintering method. The effects of the FA and MPD on the bonding strength of the sinter were investigated by a bonding test of quasi-particles. The results show that during the assimilation between the primary liquid phase and haematite ore, the gangues dissolve in the primary liquid phase, promoting the transformation of quasi-calcium ferrite into quasi-calcium silicate liquid. After solidification and precipitation, the two liquids turn into the silico-ferrite of calcium and aluminium and Fe₂O₃-bearing silicates. Increasing SiO₂ or Al₂O₃ content decreases the FA by raising the viscosity of the primary liquid phase. However, it increases the MPD by reducing the quaternary basicity of the adhering fines and elevating the wettability of the liquid phase. The FA has a positive effect on the bonding strength of the sinter, whereas the effect of the MPD may be indirectly negative.