Recovery of carbon and cryolite from spent pot lining of aluminium reduction cells by chemical leaching
| Autor: | Wei Li, Bingliang Gao, Zhaowen Wang, Zhongning Shi, Xian-wei Hu, Bijun Ren |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Inorganic chemistry Metals and Alloys Mixing (process engineering) chemistry.chemical_element Geotechnical Engineering and Engineering Geology Condensed Matter Physics Aluminium electrolysis Cryolite chemistry.chemical_compound chemistry Aluminium Materials Chemistry Leaching (metallurgy) Dissolution Carbon |
| Zdroj: | Transactions of Nonferrous Metals Society of China. 22:222-227 |
| ISSN: | 1003-6326 |
| DOI: | 10.1016/s1003-6326(11)61164-3 |
| Popis: | A two-step alkaline-acidic leaching process was conducted to separate the cryolite from spent pot lining and to purify the carbon. The influencing factors of temperature, time, and the ratio of liquid to solid in alkaline and acidic leaching were investigated. The results show that the recovery of soluble compounds of Na 3 AlF 6 and Al 2 O 3 dissolving into the solution during the NaOH leaching is 65.0%, and the purity of carbon reaches 72.7%. During the next step of HCl leaching, the recovery of soluble compounds of CaF 2 and NaAl 11 O 17 dissolving into the HCl solution is 96.2%, and the carbon purity increases to 96.4%. By mixing the acidic leaching solution and the alkaline leaching solution, the cryolite precipitates under a suitable conditions of pH value 9 at 70°C for 2 h. The cryolite precipitating rate is 95.6%, and the purity of Na 3 AlF 6 obtained is 96.4%. |
| Databáze: | OpenAIRE |
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