Dissertation
INVESTIGATION OF TRIVALENT NEODYMIUM AND EUROPIUM OXALATE CRYSTALLIZATION PROCESSES: THERMODYNAMIC MODELING, SPECTROSCOPY, AND MICROSCOPY ANALYSIS
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005452
Handle:
https://hdl.handle.net/2376/119646
Abstract
Industrial separation and purification processes includes the use of oxalic acid to precipitate rare earth elements (REEs) such as neodymium and europium. Understanding how initial solution affect the final crystal morphology is of fundamentally importance and supports design of environmentally effective processes. This work investigates the interplay of thermodynamics and kinetics on crystallization processes by using a combination of thermodynamic modeling, spectroscopy, and microscopy techniques. The use of thermodynamic modeling on neodymium and europium oxalate in acidic media demonstrated comparable results to work reported in literature. Experiments have shown multiple spectroscopic techniques permit real-time, simultaneous observation of the total europium(III) ad neodymium(III) concentration change in the aqueous phase and the precipitate solid formation leading to a better understanding of the mechanism of the crystallization process. Our results have shown varying initial solution conditions leads to differences in solution kinetics along with particle morphology and size distribution. The combination of microscopy techniques allowed in situ observations and kinetic insights on the early stages of particle growth to understand how variations in precipitation conditions can affect the morphology of the solid product. Results indicate that particle growth rates depend on neodymium(III) concentration and strike direction, among other factors. This work aims to better understand and predict the correlation between initial solution conditions and resulting material characteristics by investigating how initial solution influences the kinetics and resulting particle morphology. Connecting the solution conditions to material properties may provide valuable information to improve aqueous processes for industrial processes.
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Details
- Title
- INVESTIGATION OF TRIVALENT NEODYMIUM AND EUROPIUM OXALATE CRYSTALLIZATION PROCESSES: THERMODYNAMIC MODELING, SPECTROSCOPY, AND MICROSCOPY ANALYSIS
- Creators
- Tenisha Meadows
- Contributors
- Sue Clark (Advisor)Cornelius Ivory (Committee Member)Edgar Buck (Committee Member)Samuel Bryan (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Chemistry
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 172
- Identifiers
- 99900592258801842
- Language
- English
- Resource Type
- Dissertation