The film theory model was used to model limestone dissolution from a plane surface. In the experimental design a limestone cylinder rotated in an aqueous solution. The effects of pH, cylinder speed, partial pressure of carbon dioxide and temperature on the dissolution rate were investigated. The results show that the mass transfer mode1 describes very well the dependence of the four parameters within the ranges investigated. Compared with dissolution in a nitrogen atmosphere, a high partial pressure of carbon dioxide increases the dissolution rate by up to a factor of 10. This is attributed to the carbonate system acid-base reactions. The dissolution rate in a nitrogen atmosphere can with good accuracy be written Ra a$ +. The results show that q is a function of pH and film thickness. The film theory model predicts and describes this behavior which previously has not been explained theoretically. The activation energy for dissolution in a nitrogen atmosphere is 16.2 & 1.5 kJ/mol. The activation energy increases for dissolution in a carbon dioxide atmosphere. BACKGROUND dissolution: Limestone dissolution in an aqueous solution is a phenomenon of interest in several areas: R = kr aH + + k,, aH,coJ + km aHa m Liming of acid lakes. l Flue gas desulfurization. l Preservation of buildings. Knowledge of limestone dissolution dependence on hydrodynamic and chemical conditions can optimize the efforts carried out in the areas listed above. where k,, k,, and k,, are rate constants, and k, is dependent on both pm, and temperature. The experiments showed that .Limestone dissolution has previously been studied from a rotatihg disc or particles. Sjiiberg and Rickard (1984a, b, 1985) studied dissolution from a rotating limestone disc in an aqueous solution and a nitrogen atmosphere. Their results were treated according to the theory for rotating discs (Levich, 1962). The following were observed: