Research on the utilisation of precipitated calcium carbonate for gas sweetening. I. A comparative study on the precipitated calcium carbonate reactivity

After presenting the sulphur dioxide interaction mechanism with natural and synthetic carbonates, the comparative reactivity of four carbonate grades i.e. magnesite, dolomite, limestone and precipitated calcium carbonate, in an air-sulphur dioxide flow, of different concentrations, was experimentall y and thermogravimetrically studied. The sulphation study was performed in isothermal conditions, concomitantly or after the carbonates decomposition. Following this study, it was found out that the calcium oxide reactivity, obtained by the thermal decomposition of the four carbonate grades, was in the order limestone/precipitated CaCO3 / dolomite / magnesite. Under the co nditions of securing the necessary sulphur dioxide, it is possible to have an advanced sulphating of the precipitated calcium carbonate, the relative mass of the searched samples going in excess of one, towards the theoretica l limit value of 1.21.