Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation
Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such solutions result from leaching calcium aluminate slags with sodium carbonate solutions, in accord...
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MDPI AG
2021-07-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/11/7/836 |
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| author | Danai Marinos Dimitrios Kotsanis Alexandra Alexandri Efthymios Balomenos Dimitrios Panias |
| author_facet | Danai Marinos Dimitrios Kotsanis Alexandra Alexandri Efthymios Balomenos Dimitrios Panias |
| author_sort | Danai Marinos |
| collection | DOAJ |
| description | Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such solutions result from leaching calcium aluminate slags with sodium carbonate solutions, in accordance with the Pedersen process, which is an alternative process for alumina production. The concentration of carbonate ions in the pregnant solution is revealed as a key factor in controlling the nature of the precipitating phase. Synthetic aluminate solutions of varying sodium carbonate concentrations, ranging from 20 to 160 g/L, were carbonated, and the resulting precipitating phases were characterized by X-ray diffraction analysis. Based on the results of the previous carbonation tests, a series of experiments were performed in which the duration of carbonation and the aging period of the precipitates varied. For this work, a synthetic aluminate solution containing 20 g/L free Na<sub>2</sub>CO<sub>3</sub> was used. The precipitates were characterized with X-ray diffraction analysis and Fourier-transform infrared spectroscopy. |
| first_indexed | 2024-03-10T09:41:54Z |
| format | Article |
| id | doaj.art-31710db5b57c40038802c7fa07a7c2b9 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T09:41:54Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-31710db5b57c40038802c7fa07a7c2b92023-11-22T03:33:53ZengMDPI AGCrystals2073-43522021-07-0111783610.3390/cryst11070836Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite FormationDanai Marinos0Dimitrios Kotsanis1Alexandra Alexandri2Efthymios Balomenos3Dimitrios Panias4Laboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Heroon Polytechniou 9, 15780 Zografou, GreeceLaboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Heroon Polytechniou 9, 15780 Zografou, GreeceLaboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Heroon Polytechniou 9, 15780 Zografou, GreeceLaboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Heroon Polytechniou 9, 15780 Zografou, GreeceLaboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Heroon Polytechniou 9, 15780 Zografou, GreeceExperimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such solutions result from leaching calcium aluminate slags with sodium carbonate solutions, in accordance with the Pedersen process, which is an alternative process for alumina production. The concentration of carbonate ions in the pregnant solution is revealed as a key factor in controlling the nature of the precipitating phase. Synthetic aluminate solutions of varying sodium carbonate concentrations, ranging from 20 to 160 g/L, were carbonated, and the resulting precipitating phases were characterized by X-ray diffraction analysis. Based on the results of the previous carbonation tests, a series of experiments were performed in which the duration of carbonation and the aging period of the precipitates varied. For this work, a synthetic aluminate solution containing 20 g/L free Na<sub>2</sub>CO<sub>3</sub> was used. The precipitates were characterized with X-ray diffraction analysis and Fourier-transform infrared spectroscopy.https://www.mdpi.com/2073-4352/11/7/836precipitationaluminum hydroxidedawsonitesodium aluminate solutioncarbonationPedersen process |
| spellingShingle | Danai Marinos Dimitrios Kotsanis Alexandra Alexandri Efthymios Balomenos Dimitrios Panias Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation Crystals precipitation aluminum hydroxide dawsonite sodium aluminate solution carbonation Pedersen process |
| title | Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation |
| title_full | Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation |
| title_fullStr | Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation |
| title_full_unstemmed | Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation |
| title_short | Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation |
| title_sort | carbonation of sodium aluminate sodium carbonate solutions for precipitation of alumina hydrates avoiding dawsonite formation |
| topic | precipitation aluminum hydroxide dawsonite sodium aluminate solution carbonation Pedersen process |
| url | https://www.mdpi.com/2073-4352/11/7/836 |
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