Thermodynamic properties of Ni-S and Ni-S-Me melts

The partial and integral mixing enthalpies of liquid Ni - S and Ni - S - Me alloys at 1870 K are determined by calorimetry. The first partial mixing e nthalpy of sulfur in nickel is 130 +/- 20 kJ/mole, which agrees with litera ture data. The activity of nickel in the range 0.5 < x(Ni) < 1 is calculate d from the Ni - S phase diagram, with extrapolation of the results over the whole concentration range; the activity of sulfur is calculated from the G ibbs - Duhem equation. The activity of sulfur is characterized by very larg e negative deviations from Raoult's law. The partial solution enthalpies of a number of metals in Ni - S melts are determined. According to the result s, the exothermal effect is greatest for the solution of La and Ce, which m ay be used as strong sulfur-removal agents.