The activity coefficient of cobalt oxide in silica-saturated iron silicate slags

The solubility of cobalt oxide in silica-saturated iron silicate slags (1.16 to 10.00 wt pct) in equilibrium with cobalt-gold-iron alloys (1.10 to 6.52 wt pct cobalt) and oxygen pressures of 10₋₉ to 10₋₁₀ atm (1 atm = 1.013 x 105 Pa) has been investigated at 1573 K. The activity coefficient of cobalt oxide, γ_CoO, has been calculated relative to pure solid cobalt oxide as standard, namely, γ_CoO = 0.91 ± 0.09 and a relationship derived between weight percent cobalt in slag, Co (wt pct), oxygen pressure, pO₂, and activity of cobalt relative to liquid cobalt,aCo, namely, Co (wt pct) = 1.32 x 10⁶ pO ₂ ^1/2 a_Co ± 10 pct Both errors are calculated at the 95 pct confidence level. Formerly Senior Lecturer in Pyrometallurgy, Murdoch University, Murdoch, Western Australia Formerly Postgraduate Student, Murdoch University, Murdoch, Western Australia