ABSTRACT
The studies of metal oxide dissolution that explore experimental conditions under which massive transformations take place provide valuable information for the characterization of the chemical and physical processes involved in the dissolution reaction. The successive features of the profile are: an initial fast reaction of limited extent, soon arrested; an induction period, during which the rate is close to zero; an acceleratory stage, with rates increasing with time that may proceed up to a large value of f (0.5 to 0.6); and a deceleratory stage at high degrees of conversion. This chapter presents the kinetic equations that account for the different behaviors and derives rate constants from the analysis of the profiles. Nucleation and growth models for solid-state kinetics are based on the idea that the formation of a new phase requires a barrier associated with the important contribution of interfacial energy in the very early stages of reaction to be surmounted.
