Kinetics of the conversion reaction of gypsum with ammonium carbonate

The reactivity of flue gas desulphurization gypsum with ammonium carbonate has been studied in the temperature range (20-50) A degrees C. Mechanism of this reaction was suggested and the kinetics parameters characterizing the reaction were determined. A mathematical model suitable for the prediction of the conversion of gypsum was proposed. The reaction is of the second order. Influence of the size of gypsum particles on the relationship between the surface and volume of the particles is not significant. From the obtained experimental results, it follows that the reaction does not proceed at the surface of the solid gypsum particles, but in the liquid phase between dissolved gypsum and ammonium carbonate. The diffusion of the dissolved gypsum through the liquid film formed at the surface of the solid gypsum particles is the rate-limiting step of the conversion reaction.