The distribution of cobalt between Co-Cu alloys and Al₂O₃-FeO-Fe₂O₃-SiO₂ slags

The solubility of cobalt in alumina-containing iron silicate slags (0.092-3.365 wt% Co) in equilibrium with cobalt-copper-iron alloys (0.070-6.351 wt% cobalt) and oxygen pressures of 1.125 · 10^-8, 2.396 · 10^-9 and 4.536 · 10^-10 atm has been studied at 1673 K. It has been found that: (i) the solubility of cobalt in the slag increased with increase in concentration of cobalt in the alloy, and also increased with increasing oxygen partial pressure in the atmosphere at a fixed concentration of cobalt in alloy; and (ii) the activity coefficient of cobalt oxide in the slag increased with increasing cobalt oxide in the slag and/or decreasing oxygen partial pressure in the system.