Imperial College London
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Professor Sue Grimes

Faculty of Engineering, Department of Civil and Environmental Engineering

RAEng Chair in Waste & Resource Management
 
 
 
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Contact

 

+44 (0)20 7594 5966s.grimes

 
 
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Location

 

233Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Schaeffer:2015:10.1016/j.ica.2015.09.015,
author = {Schaeffer, N and Grimes, S and Cheeseman, C},
doi = {10.1016/j.ica.2015.09.015},
journal = {Inorganica Chimica Acta},
pages = {55--60},
title = {Interactions between trivalent rare earth oxides and mixed [Hbet][Tf2N]:H2O systems in the development of a one-step process for the separation of light from heavy rare earth elements},
url = {http://dx.doi.org/10.1016/j.ica.2015.09.015},
volume = {439},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The factors, including ionic liquid:water ratios, temperature, solvent:solute contact times, and the effect of dissolved rare earth metal ions on the [Hbet][Tf2N]:H2O thermometric phase change are determined to develop a process for separating the light from the heavy rare earth metal oxides in [Hbet][Tf2N]:H2O mixtures. The relative solubility data for three light (La2O3, Nd2O3, and Eu2O3), two heavy (Y2O3 and Yb2O3) rare earth metal oxides (REOs), and Gd2O3 at different temperatures and different solute:solvent contact times are reported for 1:1 [Hbet][Tf2N]:H2O. The light REOs dissolve easily at 57 °C with the La and Eu reaching maximum solubility within minutes while the heavy REOs have very low solubilities at this temperature with negligible amounts being dissolved for contact times less than 80 min. Gd2O3 dissolves more slowly than the La, Eu, and Nd oxides at 57 °C reaching maximum solubility only after 160 min. Changing the [Hbet][Tf2N]:H2O ratio from 1:1 to 16:1 increases the time required to dissolve the REOs. The times taken to reach maximum solubility decrease for all of the REOs up to 95 °C, resulting in the separations between the light and heavy rare earth elements, and Gd becoming less distinct. The presence of rare earth metal ions in [Hbet][Tf2N]:H2O results in a reduction in the upper critical solution temperature (UCST) of the solvent from 55.6 °C to as low as 31.8 °C with Gd3+. The best separation of light from heavy REOs is achieved at 57 °C but better separation of Gd from the light REOs is achieved at 40 °C, below the solvent UCST. The best conditions for a one-step separation of light from heavy REOs in [Hbet][Tf2N]:H2O mixtures is achieved with 1:1 [Hbet][Tf2N]:H2O at 57 °C using short contact oxide:solvent times (maximum 5 min). Separations of light from heavy REOs, in waste phosphor samples, containing La2O3, CeO2, Eu2O3, Gd2O3, Tb3O4 and Y2O3, are also achieved even in the presence of high concentrations
AU  - Schaeffer,N
AU  - Grimes,S
AU  - Cheeseman,C
DO  - 10.1016/j.ica.2015.09.015
EP  - 60
PY  - 2015///
SN  - 1873-3255
SP  - 55
TI  - Interactions between trivalent rare earth oxides and mixed [Hbet][Tf2N]:H2O systems in the development of a one-step process for the separation of light from heavy rare earth elements
T2  - Inorganica Chimica Acta
UR  - http://dx.doi.org/10.1016/j.ica.2015.09.015
UR  - http://hdl.handle.net/10044/1/39635
VL  - 439
ER  -
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