Separation of ceria-based abrasive from ceria-based glass polishing powder waste by liquid-liquid extraction
| Autor: | Yu-Hua Jiang, 江育華 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 In the manufacture process of panel glass, ceria-based abrasive is often used in chemical mechanical polishing to remove fine scratches caused by etching treatment. After polishing, a ceria-based glass polishing powder waste containing ceria-based abrasive and polished glass powder is produced. The waste is discarded into landfill nowadays. In order to promote the recycling of rare earth metal resources, it is necessary to recovery ceria-based abrasive from ceria-based glass polishing powder waste. In this research, the separation of ceria-based abrasive from ceria-based glass polishing powder waste by liquid-liquid extraction was studied. Kerosene was used as organic phase. The effects of pH and surfactant collector addition including NaOL, SDS, and DAA on the extracted fraction of ceria-based abrasive and glass powder, as well as on the mutual separation of the two particles were investigated. Finally, the optimal separation conditions were applied to a ceria-based glass polishing powder waste. The results showed that with the addition of NaOL or SDS at pH ranging from 5 to 9, or DAA at pH ranging from 7 to 9, more than 90% ceria-based abrasive can be extracted to the kerosene phase whereas only 10~20% glass powder was extracted. The optimal conditions for the mutual separation of ceria-based abrasive and glass powder were obtained when 7.5 kg/ton NaOL was added at pH 7 and when 2.5 kg/ton SDS was added at pH 9. Under these conditions, the grade and recovery of ceria-based abrasive in the kerosene phase solids was 100% and 98.3%, respectively. After applying the same conditions to a ceria-based glass polishing powder waste, the grade and recovery of that were both more than 80%. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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