| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 230083 | The Journal of Supercritical Fluids | 2016 | 7 Pages |
•Solubilities of metal-ligands complex in supercritical CO2 accurately determined.•The use of trioctylamine ligand shows poor extraction efficiency and selectivity.•Extraction of Mo with 2-ethylhexyl 2-ethylhexylphosphonic acid is efficient.•The selectivity of the extraction depends on operating conditions.
The development of environmental-friendly process for strategic metal extraction, limiting organic solvent use and effluent production, appears to be quite a challenging purpose. Production of pure molybdenum using supercritical CO2 extraction process, from sulfuric solution obtained by ore or used catalyst leaching, has been evaluated. Two organic ligands, trioctylamine and 2-ethylhexyl 2-ethylhexylphosphonic acid, were studied to extract Mo as metal complexes solubilized in supercritical CO2. Extraction with trioctylamine revealed to be non-efficient due to a lack of Mo-trioctylamine complex solubility in CO2, even if extraction selectivity of molybdenum versus iron impurity was interesting. On the contrary, extraction with 2-ethylhexyl 2-ethylhexylphosphonic acid leads to high Mo collection efficiency (up to 90% in 7 h). However, no selectivity was observed between molybdenum and zirconium. The selectivity of 2-ethylhexyl 2-ethylhexylphosphonic acid towards molybdenum in presence of iron was better but clearly decreased in presence of zirconium.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
