SURFACE AND INTERFACIAL-TENSION OF THE NI-FE-S, NI-CU-S, AND FAYALITESLAG SYSTEMS

The surface tensions of the Ni-Fe-S system together with the Ni-Cu-S a nd fayalite-type slag systems were measured using the sessile drop tec hnique. Drop images were obtained by X-ray radiography. For the Ni3S2- FeS pseudo-binary system, the surface tension of the matte increased w ith matte grade and showed a positive deviation from ideality with mat te grade. This suggests that Ni3S2 dominates in the nickel matte syste m. The results also indicated that a fluctuation in the matte nickel c ontent can alter the surface tension quite significantly. A ternary su rface tension plot of the Ni-Fe-S system showed that the addition of e ither Ni or S to the matte alters the surface tension. On the other ha nd, at a constant Ni:S ratio, the addition of iron has negligible infl uence on the surface tension of the matte. The measured surface tensio n of the Ni-Cu-S system also showed a nonlinear relationship with the Cu2S content in the matte. The surface tension decreased with Cu2S con tent. The interfacial tension of the Ni-Fe-S and slag system was found to increase with increasing matte grade. The presence of MgO and Al2O 3 in the slag did not affect the interfacial tension value.