Efficient recovery of highly pure CaF2 from fluorine-containing wastewater using an icy lime solution
© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).
| Veröffentlicht in: | Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 90(2024), 1 vom: 15. Juli, Seite 32-44 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Water science and technology : a journal of the International Association on Water Pollution Research |
| Schlagworte: | Journal Article calcium fluoride fluoride-containing wastewater kinetics thermodynamics Calcium Fluoride O3B55K4YKI Wastewater Fluorine 284SYP0193 mehr... |
| Zusammenfassung: | © 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/). Developing a feasible and low-cost strategy for the recovery of calcium fluoride efficiently from fluoride-containing wastewater is very essential for the recycle of fluoride resources. Herein, a modified lime precipitation method was employed to recover CaF2 from fluorinated wastewater using a special icy lime solution. Intriguingly, the highest F- removal was greater than 95% under the optimal condition, leaving a fluoride concentration from 200 to 8.64 mg/L, while the lime dosage was much lower than that of industry. Importantly, spherical-shaped CaF2 particles with a 93.47% purity and size smaller than 600 nm were recovered, which has a high potential for the production of hydrofluoric acid. Besides, the precipitation was significantly affected by Ca/F molar ratio, stirring time, temperature, and solution pH. Furthermore, the thermodynamics and kinetics were investigated in detail to reveal the crystallization process. As a result, the defluorination reaction followed the pseudo-second order reaction kinetics model. Also, CO2 in the air adversely influenced the CaF2 purity. Based on this facile method, a high lime utilization efficiency was applied to defluorination, which contributed to protecting the environment and saving costs. This study, therefore, provides a feasible approach for the green recovery of fluorine resources and has significance for related research |
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| Beschreibung: | Date Completed 15.07.2024 Date Revised 15.07.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 0273-1223 |
| DOI: | 10.2166/wst.2024.211 |