2017 Volume 57 Issue 2 Pages 236-244
In the steel refining process, a metal emulsion in which metal droplets are dispersed in the slag phase plays an important role in improving the reaction efficiency. In a previous study, the formation of metal emulsions was experimentally evaluated using Pb or Al alloys as the metal phase and chloride salt as the slag phase. In this study, the formation of metal emulsions was investigated by using a Sn alloy-salt system, and the influence of the density was clarified. The results revealed that the number, surface area, volume, and mass of emulsified metal droplets were largest in the Al/salt system, while those in the Sn/salt system were similar to those in the Pb/salt system. The formation and sedimentation rates of metal droplets were analyzed based on a mathematical model. The formation rate was also largest in the Al/salt system, while that in the Sn/salt system was similar to that in the Pb/salt system. The bubble rupture frequency showed a similar difference according to the metal phase, and it was shown that the formation rate was strongly influenced by the bubble rupture frequency. In addition, a clear relation between the formation rate by a single gas bubble and the density ratio of the upper and lower phases was found.