THE SURFACE-TENSION AND DENSITY OF CU2S, FES, NI3S2 AND THEIR MIXTURES

The surface tension and density of the Cu2S, FeS. and Ni3S2 systems we re determined as a function of temperature and composition using the m aximum bubble pressure technique. The densities of these molten sulphi des were found to decrease linearly with increasing temperature. In th e temperature range 1273-1573 K. surface tension of both FeS and Cu2S remained relatively constant. On the other hand. the results for Ni3S2 , showed a linear decrease in surface tension with increasing temperat ure. Surface tensions and densities of the Cu2S-FeS. Cu2SNi3S2. and Ni 3S2-FeS pseudo-binary together with the Cu2S-Ni3S2-FeS pseudo-ternary systems were measured at 1473 K. For the pseudo-binary systems con tai nince Ni3S2, the surface tension of the mixtures increased linearly wi th Ni3S2 content. Results for the Cu2S-FeS system exhibited a non-line ar relationship with FeS acting as a surface active agent. In the pseu do-ternary system, the results indicated that the addition of Cu2S to the system has only a limited effect on surface tensions. densities an d molar volume.