Effect of Oxygen Blowing on Copper Droplet Formation and Emulsification Phenomena in the Converting Process

Abstract

The effect of oxygen on interfacial phenomena between slag and copper melt was investigated at 1400 degrees C. The removal of impurities (iron and silicon) in the copper melt during oxygen blowing was confirmed. Also, it was revealed that composition change of the slag occurs due to the oxygen potential in the slag depending on the oxygen injection method. In addition, over-blowing of oxygen after removing impurities is a factor that significantly changes the surface tension of molten copper and slag. Over blown oxygen increases the instability of the interface by reducing interfacial tension between slag and liquid copper. Due to lowered interfacial tension and increased instability, copper droplets can be mixed into slag phase which induces copper loss. Oxygen blowing and/or bubbling is involved in chemical and weak physical reactions in the gas-slag-metal multiphase system, which should be carefully controlled because it is significant factor affecting the recovery rate of the metal.