Batch dissolution of fine limestone particles in HCl solutions was studied in a baffled tank reactor stirred with a Rushton turbine using a pH-drift technique. The effects of both acid strength and stirring rate were analyzed by varying the initial pH in the range of 3.7-5 and the impeller Reynolds number in the range of 10(4)-10(5). The main experimental result is that, after a very fast step that leads to a quick rise of the solution pH, the dissolution rate is strongly affected by CO2 gas-liquid mass transfer, the intensity of which depends on the rate of stirring. A diffusional model based on film theory was used to analyze the data. The model confirmed that, for the operating conditions considered, a very short time is necessary for the first step of the dissolution process to take place. Furthermore, by taking into account the two limiting cases of the absence Of CO2 gas-liquid transport and of infinitely fast transport, it was possible to identify lower and upper bounds for the experimental Ca2+ concentration.