Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1797349 | Journal of Crystal Growth | 2006 | 7 Pages |
Abstract
The size of the seeds and the porosity of the fluidized bed have little influence on the steady growth of KCl crystals, but affect the dissolution and, to a lesser extent, the initial stages of growth. The diffusive nature of dissolution is well illustrated by an activation energy of 8.5±1.0 kJ molâ1. The corresponding values pertaining to growth experiments with 5 and 20 min of residence time were (23.9±4.4 and 39.1±1.7) kJ molâ1, respectively, thus indicating a significant role of the diffusional mass transfer step during the early contact of the seeds with the solution. As the growth rates approach a constant value, the importance of this step decreases relatively to the surface-reaction contribution. The linear correlation between growth rates and driving force suggests, therefore, a growth process controlled by a direct integration mechanism.
Related Topics
Physical Sciences and Engineering
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Condensed Matter Physics
Authors
Ana Lopes, Fátima Farelo,