REE(III) recovery from spent NiMH batteries as REE double sulfates and their simultaneous hydrolysis and wet-oxidation
Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.
| Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 107(2020) vom: 15. Apr., Seite 66-73 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
| Schlagworte: | Journal Article Cerium Selective dissolution Spent NiMH batteries Wet oxidation Metals Metals, Rare Earth Sulfates Nickel 7OV03QG267 |
| Zusammenfassung: | Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved. Efficient recovery of REEs present in the battery waste is a modern problem that has proven to be difficult to solve in an efficient manner. The raw material investigated in the current study is mixed alkaline rare earth element (REE) double sulfate (DS) precipitate, originating from the sulfuric acid leachate of nickel-metal hydride battery (NiMH) waste. Typically, REE can be precipitated as a mixture of REE double sulfates, however the real challenge is the separation of REEs from each other's into pure fraction. The study elucidates the process by which the DS are transformed into hydroxides with simultaneous in-situ conversion of Ce(III) to Ce(IV) by air. Air flow rate (0-1 L/h), temperature (30-60 °C), liquid-solid ratio (L/S, 12.5-100 g/L), 3REE/NaOH mol ratio (1-1.6) and time (60-240 min) were varied in the study of oxidation and double sulfate conversion. Best oxidation achieved was 93% along near-complete dissociation of double sulfate matrix (52767 ppm Na reduced to 48 ppm Na). After parameter optimization, a larger batch was produced to conduct selective dissolution of REE(III) into HNO3 media, leaving concentrated impure Ce(OH)4 as the end product |
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| Beschreibung: | Date Completed 21.05.2020 Date Revised 21.05.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2020.03.042 |