| Abstract: | With the aid of surface and interfacial tension data it has been possible to clarify the effect of the elements nickel, titanium and sulphur in steel and titanium oxide and sulphur in slag on the emulsifying or separating tendencies of liquid steel/molten slag phases. This has been related to the tendency of (scattered) liquid steel films to adhere to gas bubbles crossing the interface, which in turn leads to the formation of metal droplets in the slag phase. Nickel containing steels tend to form emulsions, whereas titanium, both dissolved in the steel and as titanium oxide in the slag, tends to suppress adherence of the steel to the bubbles and promotes steel/slag separation. Sulphur containing steels show also an emulsifying tendency in contact with both sulphur containing and sulphur free slags. With sulphur present in the slag, however, the opposite effect is observed, so that, as sulphur transfer proceeds between the steel and the slag during desulphurization, the emulsifying tendency is markedly reduced, leading to steel/slag separation. |
