CALORIMETRIC INVESTIGATION OF KINETICS OF SOLID-PHASE DISSOLUTION - CALCIUM-CARBONATE DISSOLUTION IN AQUEOUS EDTA SOLUTION

The calorimetric method for examination of the kinetics of solid phase dissolution is presented. The thermograms are interpreted by consider ing the heat evolution due to the reaction as well as the heat transfe r in the calorimeter. The kinetic interpretation is based on the chang e of particle surface area during the dissolution process. The experim ental results confirm the applicability of the proposed method. The ra te constant and the enthalpy of dissolution of solid CaCO3 in aqueous EDTA and NaOH solutions are determined. The experiments show that the process is the first order with respect to the surface area, indicatin g that the detachment of EDTA complex from the surface is the responsi ble mechanism. (C) 1997 Academic Press.