Sulphate crystallization modelling and surface reactivity in solution

The hydration of mineral phases corresponds to dissolution - precipitation mechanisms. A model considering crystallization pressure and particle size distribution of both anhydrous and precipitate sulphate is proposed. The model is applied in the case of β-plaster hydration in a solute. Numerical results demonstrate that the hydration process can be viewed as the sequence of nucleation, high growth regime and decreasing growth regime. Modifications in the particle size distribution and reactivity surface are characteristic of each phase.