The effect of temperature and ionic strength on iron carbonate (FeCO 3) solubility limit

In CO 2 corrosion, precipitation of iron carbonate can significantly reduce the corrosion rate of the underlying steel. Precipitation rate depends on a reliable calculation of the iron carbonate solubility limit. The open literature does not provide an expression for iron carbonate solubility that covers a wide enough range of parameters. In this study a unified iron carbonate solubility ( K sp in mol 2/L 2) expression is developed based on the literature data: log K sp = - 59.3498 - 0.041377 T k - 2.1963 T k + 24.5724 log ( T k ) + 2.518 I 0.5 - 0.657 I which accounts for both temperature and ionic strength effects. The predictions made with this unified equation agree well with the published experimental data.