Transferencia de masa y criterios de cristalización en el crecimiento en geles de cristales de estroncianita
- Manuel Prieto 1
- Lourdes Fernández Díaz
- Sol López Andrés
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1
Universidad de Oviedo
info
ISSN: 0210-6558
Datum der Publikation: 1989
Ausgabe: 12
Nummer: 0
Seiten: 77-89
Art: Artikel
Andere Publikationen in: Boletín de la Sociedad Española de Mineralogía
Zusammenfassung
Supersaturation is not enough to interpret nucleation phenomena in crystal growth in gels. The explanation of the first precipitate location needs complementary crystallization criteria. The experimental testing of both, mass-transfer and pH evolution, is the background to establish rigorous hypothesis. From these data, the actual distribution of free ions, ionic associations and supersaturation throughout the gel column may be known. In the case of nucleation and growth of strontianite crystals, the experimental results show that a complementary hypothesis isneccesary: the “equality range” of the reagent’s concentration. The significance of both, the concentration influence in the reagent’s diffusivity and the pH evolution, is also experimentally shown. Nucleation density and growth mechanisms are finally explained in base to supersaturation velocity and kinetics roughness.