EQUILIBRIUM DISTRIBUTION OF FE, NI, SB, AND SN BETWEEN LIQUID CU AND A CAO-RICH SLAG

Equilibrium measurements of the distribution of Fe, Ni, Sb, and Sn bet ween a liquid Cu-O solution and a CaF2-CaO-MgO-SiO2 were carried out a t 1500 K in a magnesia crucible. The results show that the studied sol utes were in the states Fe(III), Ni(II), Sb(III), and Sn(IV), in the s lag, for metal O contents ranging from 100 ppm to saturation at 2.1 pc t. The Cu oxide solubility in the slag was also measured in absence of the solute elements. Its maximum solubility is about 4 +/- 1 mass pct Cu2O. The compositions at equilibrium allow determination of the acti vity coefficients (referred to pure oxide) of the four solute oxides i n the slag. These values, expressed in round figures to take into acco unt the experimental uncertainties, are 10 for Fe2O3, 20 for NiO, 10 f or SnO2, 1.6 10(-2) for SbO1.5, and 60 for Cu2O.