A Molecular-Scale Approach to Rare-Earth Beneficiation: Thinking Small to Avoid Large Losses
| Autor: | Alexander Kisliuk, Santa Jansone-Popova, Robert C. Chapleski, Robert L. Sacci, Andrew G. Stack, Azhad U. Chowdhury, Dylan Everly, Vyacheslav S. Bryantsev, Anna K. Wanhala, Benjamin Doughty, Corby G. Anderson, Philip C. Keller, Vera Bocharova, Santanu Roy |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Materials science Metal ions in aqueous solution Physical Inorganic Chemistry 02 engineering and technology Article 03 medical and health sciences chemistry.chemical_compound Molecule Froth flotation lcsh:Science Spectroscopy Calcite Multidisciplinary Beneficiation Chemical Engineering 021001 nanoscience & nanotechnology Bastnäsite 030104 developmental biology chemistry Chemical engineering Gangue lcsh:Q Density functional theory 0210 nano-technology Surface Chemistry |
| Zdroj: | iScience, Vol 23, Iss 9, Pp 101435-(2020) iScience |
| ISSN: | 2589-0042 |
| Popis: | Summary Separating rare-earth-element-rich minerals from unwanted gangue in mined ores relies on selective binding of collector molecules at the interface to facilitate froth flotation. Salicylhydroxamic acid (SHA) exhibits enhanced selectivity for bastnäsite over calcite in microflotation experiments. Through a multifaceted approach, leveraging density functional theory calculations, and advanced spectroscopic methods, we provide molecular-level mechanistic insight to this selectivity. The hydroxamic acid moiety introduces strong interactions at metal-atom surface sites and hinders subsurface-cation stabilization at vacancy-defect sites, in calcite especially. Resulting from hydrogen-bond-induced interactions, SHA lies flat on the bastnäsite surface and shows a tendency for multilayer formation at high coverages. In this conformation, SHA complexation with bastnäsite metal ions is stabilized, leading to advanced flotation performance. In contrast, SHA lies perpendicular to the calcite surface due to a difference in cationic spacing. We anticipate that these insights will motivate rational design and selection of future collector molecules for enhanced ore beneficiation. Graphical Abstract Highlights • Salicylhydroxamic acid (SHA) is an effective collector for flotation of bastnäsite • DFT calculations show that the phenol group anchors SHA flat to bastnäsite surface • Spectroscopic results suggest SHA multilayers on bastnäsite at high coverage • This peculiar adsorption explains efficacy of SHA in bastnäsite flotation from ores Chemical Engineering; Spectroscopy; Physical Inorganic Chemistry; Surface Chemistry |
| Databáze: | OpenAIRE |
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