Tantalum recovery from alkaline leachates based on magnesium hexatantalate intermediate precipitate
A new approach for the recovery of tantalum (Ta(v)) from alkaline solutions is presented, with the expected environmental benefits. This method is based on magnesium-induced precipitation to extract tantalum present as polyoxotantalates (POTas) from alkaline leachates. We obtained a tantalum precipitation yield of over 99% by introducing a Mg/Ta<sub>6</sub> ratio of ≥4 into the solution. We show that Ta(v) ions, as hexatantalate species, precipitate in the presence of magnesium ions to form Mg<sub>4</sub>Ta<sub>6</sub>O<sub>19</sub>·<i>x</i>H<sub>2</sub>O crystalline phases with two different structures, with <i>x</i> = 16.1 or 24.4. The magnesium tantalate precipitate is then dissolved in ethylenediaminetetraacetic acid (EDTA) to release Mg(ii) in the form of an Mg(EDTA)<sup>2-</sup> complex. The final product, amorphous hydrated tantalum pentoxide (Ta<sub>2</sub>O<sub>5</sub>·nH<sub>2</sub>O), is obtained by neutralizing the Mg-EDTA-POTa solution to pH 7. After thorough washing with dilute acid and ultrapure water and calcination, tantalum pentoxide is obtained.
Authors
- Domitille Giaume (ORCID: https://orcid.org/0000-0001-7369-0872)
- Rana Choumane (ORCID: https://orcid.org/0000-0002-0877-9982)
- Grégory Lefèvre (ORCID: https://orcid.org/0000-0002-1054-906X)
- Mbolantenaina Rakotomalala Robinson
Institutions
- Centre National de la Recherche Scientifique (FR)
- Chimie ParisTech - PSL (FR)
- Université Paris Sciences et Lettres (FR)
- Institut de Recherche de Chimie Paris (FR)
Publication Details
- Journal
- RSC Advances
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5ra02721g
- Primary Topic
- Extraction and Separation Processes
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Agence Nationale de la Recherche