extraction and separation of rare earth elements by hybrid nanoadsorbents.
Polido Legaria, Elizabeth
(2018).
Nanotechnology for hydrometallurgy.
Diss. (sammanfattning/summary)
Uppsala, Sweden :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2018:7
ISBN 978-91-7760-154-8
eISBN 978-91-7760-155-5
[Doctoral thesis]
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Abstract
Rare Earth Elements (REE) are a group of 17 chemically similar metals that have gained an increasing importance over the past decades, due to their unique properties that make them crucial for many applications, especially in high-tech products. The term “rare” is rather historical than descriptive, since they are quite abundant in the Earth’s crust. However, their extraction and separation can be challenging. This thesis aims to develop a competitive technology, based on functional nanoadsorbents, for extraction and separation of REE in solution that can be industrially applied.
Silica (SiO2) nanoparticles (NPs) with an iron oxide core were selected as the base for the nanoadsorbents. Nanoscale SiO2 exhibits a large surface area that is very advantageous for adsorption purposes. Furthermore, they can be surface functionalized with different organic molecules (ligands). The iron oxide core allows the solid nanoadsorbents to be easily removed magnetically from solution.
First, the synthesis of the nanoadsorbents was optimized and three different organosilanes were synthesized, grafted onto SiO2 NPs and tested for REE uptake. One of the three organosilanes showed to be reasonably efficient and was further tested with magnetic NP for selective uptake of REE. Structural studies of molecular model compounds gave molecular insights into the observed selectivity.
Next, adsorption conditions were carefully modified to, presumably, double the obtained REE uptake. Unexpectedly, the uptake increased up to 30 times, which suggested that a different uptake mechanism was involved. The mechanism was investigated and revealed the induced seeding of a crystalline phase of REE(OH)3 on the surface. Preliminary tests on REE carbonate from REE ores gave very encouraging results.
Finally, a deeper understanding into the selective REE uptake was achieved via structural studies of different ligands and their interaction with different REE, creating the basis for molecular recognition approach. Four ligands specific to different REE were identified and their interaction with REE explained from a molecular point of view. One of these ligands was chosen for upscaling of the technology, by evaluating its potential as packing material for chromatographic separation of REE. The studies provided very attractive results, with good separation of 6 different REE from a solution.
Authors/Creators: | Polido Legaria, Elizabeth | ||||||||||||||
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Title: | Nanotechnology for hydrometallurgy | ||||||||||||||
Subtitle: | extraction and separation of rare earth elements by hybrid nanoadsorbents. | ||||||||||||||
Series Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||||||||
Year of publishing : | 19 January 2018 | ||||||||||||||
Depositing date: | 18 January 2018 | ||||||||||||||
Number: | 2018:7 | ||||||||||||||
Number of Pages: | 117 | ||||||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala, Sweden | ||||||||||||||
Publisher: | Department of Molecular Sciences, Swedish University of Agricultural Sciences | ||||||||||||||
ISBN for printed version: | 978-91-7760-154-8 | ||||||||||||||
ISBN for electronic version: | 978-91-7760-155-5 | ||||||||||||||
ISSN: | 1652-6880 | ||||||||||||||
Language: | English | ||||||||||||||
Publication Type: | Doctoral thesis | ||||||||||||||
Full Text Status: | Public | ||||||||||||||
Agris subject categories.: | X Agricola extesions > X50 Chemistry X Agricola extesions > X60 Technology | ||||||||||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 104 Chemical Sciences > Materials Chemistry (A) Swedish standard research categories 2011 > 1 Natural sciences > 104 Chemical Sciences > Inorganic Chemistry (A) Swedish standard research categories 2011 > 2 Engineering and Technology > 205 Materials Engineering > Metallurgy and Metallic Materials | ||||||||||||||
Agrovoc terms: | nanotechnology, nanopartículas, rare earth elements, production, prossesing, extraction, separating, adsorption, adsorbents | ||||||||||||||
Keywords: | rare earth elements, silicia nanoparticles, magnetic silica nanoparticles, nanoadsorbents, hydrometallurgy, selective adsorption | ||||||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-4680 | ||||||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4680 | ||||||||||||||
ID Code: | 15256 | ||||||||||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||||||||||
Department: | (NL, NJ) > Department of Molecular Sciences | ||||||||||||||
External funders: | EU FP7 | ||||||||||||||
Deposited By: | Elizabeth Polido Legaria | ||||||||||||||
Deposited On: | 18 Jan 2018 14:11 | ||||||||||||||
Metadata Last Modified: | 09 Sep 2020 14:17 |
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