Studies on the Crystal Growth of Sparingly Soluble Salt by a Constant Composition Method
| Autor: | 洪明傑 |
|---|---|
| Rok vydání: | 1996 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 84 The aim of this study was to investigate the crystal growth of sparingly soluble salts in a semibateh crystallizer by a constant composition method. The composition of supersaturated solution was maintained constant by the potentiometrically controlled addition of reagents. When the solute decreased during the crystal growth, dosimat was modified so as to incorporate mechanically coupled burets to deliver two reagents simultaneously. Natural fluorite and natural calcite were used as seed for the calcium fluoride and calcium carbonate systems respectively in the growth process. To facilitate the ensuing experiments, the metastable region was established first. And then, the effects of operating variables, such as ionic strength、activity ratio and pH value of solution, on growth rate was examined. And the kinetics in the form of overall growth rate was established for a semibatch reactor. The result confirmed that ionic strength, activity ratio, and pH value of solution influenced the growth rate to a large extent. Finally, electrical double-layer theory was used to explain the effect of variables. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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