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Transforming waste into value: Efficient recycling of KCl and NH₄F via electrodialysis metathesis
Citation
Ruan, H., Lu, H., Wang, J., Shi, J., Zhang, Z., Liao, J., Ang, E. H., & Shen, J. (2025). Transforming waste into value: Efficient recycling of KCl and NH₄F via electrodialysis metathesis. Desalination, 600, Article 118424. https://doi.org/10.1016/j.desal.2024.118424
Author
Ruan, Huimin
•
Lu, Hao
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Wang, Jikuan
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Shi, Jiayuan
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Zhang, Zhibo
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Liao, Junbin
•
•
Shen, Jiangnan
Abstract
The synthesis of organic fluorides typically relies on the extensive use of potassium fluoride (KF), leading to substantial waste generation in the form of potassium chloride (KCl). This study addresses this global challenge by utilizing electrodialysis metathesis to recycle KCl waste and ammonium fluoride (NH₄F) into valuable products, for example, KF and ammonium chloride (NH₄Cl). We systematically explored the effect of the process conditions, including current density, feed concentration, and initial volume ratio, on the efficiency of the conversion. Under optimal conditions of 40 mA/cm2 current density, a feed concentration of 3 M, and an initial volume ratio of 1000:300, we achieved a minimal energy consumption of 0.93 kWh/kg KF, while attaining purities of 92.26 % for KF and 92.75 % for NH₄Cl. The initial purification results indicated impressive removal rates of chloride (Cl−) and fluoride (F−) ions at 96.43 % and 99.28 %, respectively. An economic evaluation of the electrodialysis process showed a production cost of 0.47 $/kg KF, alongside a potential gross profit of 0.96 $/kg KF, highlighting its viability for application.
Date Issued
2025
Publisher
Elsevier
Journal
Desalination
Project
RP 5/23 EAH
Grant ID
2024ZY01048
21878273
22008214
Funding Agency
National Liquid Separation Membrane Engineering Technology Research Center
National Natural Science Foundation of China
Ministry of Education, Singapore