1995 Volume 35 Issue 9 Pages 1063-1071
Determination of solubility and activity of calcium in liquid Fe+Ca+O alloys in equilibrium with lime at 1823 K were carried out by means of the distribution equilibrium of calcium via gas phase in a closed tantalum vessel between iron melts and Ag+Ca Alloys.
Solubility of calcium in equilibrium with lime increases with increase of calcium potential of the system. Within the concentration range from 3 to 270 mass ppm Ca, the activity coefficient of calcium referred to the hypothetical pure liquid calcium does not change apparently and its value is 7.8±0.7. Solubility of calcium in iron under the condition of both CaO and Ca+O alloy saturation was found to be 270±15 mass ppm. The partial pressure of calcium at this three phases equilibria is 1.2×105 Pa.
Based on the results and the literature data, ditermination procedure of interaction parameter between calcium and oxygen in molten iron was discussed.
