Solubility and Activity of Calcium in Molten Iron in Equilibrium with Lime and Thermodynamics of Calcium Containing Iron Melts.

Abstract

The activity data at I 073K after Fischbach almost agree with those after Delcet and Egan, however, the

Study on the Equilibrium Between Liquid Iron and Calcium Vapor

“…A comparison of the present results with values based on the data from Song and Han [1] as well as Fujiwara et al [2] is presented in Figure 3(b). The activity coefficient of calcium in silver was calculated based on the data by Fischbach, [7] as suggested by Fujiwara et al [2] It should be mentioned that only data below 110 ppm calcium in iron are included in the plot as the focus of the present study is on lower calcium contents.…”

“…However, as mentioned above, no such effect can be seen between 1823 K and 1873 K (1550°C and 1600°C) from the present data. Corresponding linear least square regression based on data from iron-silver equilibration [2] gives a value of 2162 for the activity coefficient of calcium in liquid iron at infinite dilution. A possible explanation for the observed difference between the data based on different experimental techniques could be the uncertainties related to the data for the activity coefficient of calcium in liquid silver.…”

“…The activity coefficient of calcium in silver was calculated based on the data by Fischbach, [7] as suggested by Fujiwara et al [2] It should be mentioned that only data below 110 ppm calcium in iron are included in the plot as the focus of the present study is on lower calcium contents. As shown in Figure 3(b), the presented data show a similar trend where the effect of temperature on the activity coefficient is small and the dependency of the activity of calcium on the mole fraction of calcium in iron can be approximated by a linear relationship reasonably well in the composition range studied.…”

“…Several researchers have studied the iron-rich side of the iron-calcium system at temperatures in the range of 1823 K to 1880 K (1550°C to 1607°C) using different experimental techniques. [1][2][3][4] Due to the high vapor pressure of calcium in the temperature range of interest and the stability of calcium oxide, the studies have been performed in closed or pressurized systems. In order to determine the activity coefficient of calcium in liquid iron, Song and Han [1] studied the solubility of calcium in liquid iron in equilibrium with varying calcium vapor pressures at 1873 K (1600°C), while Fujiwara et al [2] studied the partitioning of calcium between liquid iron and liquid silver at 1823 K (1550°C).…”

“…[1][2][3][4] Due to the high vapor pressure of calcium in the temperature range of interest and the stability of calcium oxide, the studies have been performed in closed or pressurized systems. In order to determine the activity coefficient of calcium in liquid iron, Song and Han [1] studied the solubility of calcium in liquid iron in equilibrium with varying calcium vapor pressures at 1873 K (1600°C), while Fujiwara et al [2] studied the partitioning of calcium between liquid iron and liquid silver at 1823 K (1550°C). Ko¨hler et al [3] and Sponseller and Flinn [4] studied the solubility of calcium in liquid iron in contact with liquid calcium at 1873 K and 1880 K (1600°C and 1607°C) in pressurized systems.…”