期刊論文
| 學年 | 103 |
|---|---|
| 學期 | 1 |
| 出版（發表）日期 | 2014-11-24 |
| 作品名稱 | Fluoride recovery from spent fluoride etching solution through crystallization of Na3AlF6 (synthetic cryolite) |
| 作品名稱（其他語言） | |
| 著者 | Chen, Jie-Yuan; Lin, Chih-Wei; Lin, Po-Han; Li, Chi-Wang; Liang, Yang-Min; Liu, Jhy-Chern; Chen,Shiao-Shing |
| 單位 | 水資源及環境工程學系暨研究所 |
| 出版者 | |
| 著錄名稱、卷期、頁數 | Separation and Purification Technology 137, pp.53-58 |
| 摘要 | Fluoride removal by precipitation of calcium fluoride is the most common practice in Taiwan to treat fluoride-containing wastewater in semiconductor or optoelectronic industries. Due to very fine CaF2 precipitates (∼0.1 μm), coagulants/flocculants are needed to facilitate sedimentation of CaF2. In turn, large amount of sludge is produced by CaF2 precipitation/sedimentation process. In this study, removal of fluoride from spent fluoride etching solution by cryolite crystallization was investigated. Experimental and chemical equilibrium modeling results show that a good control of reaction pH and Al:F molar ratio is the key to form cryolite successfully. Formation of cryolite is exothermic reaction and formation of cryolite is less favor under elevated temperature. The highest residual fluoride concentration is found at reaction temperature of 90 °C while those at 20 and 55 °C are similar. Under Al/F molar ratios of 1:3 and 1:6 and pH of 5.5, the precipitates produced at room temperature are very similar to the commercial cryolite according to XRD, SEM, and EDX analysis. Particle size of cryolite precipitates ranges from 3 μm to 15 μm and is much larger than CaF2 precipitates of 0.1 μm, resulting in rapid sedimentation. Cryolite crystallization process produces much less sludge volume than does by CaF2 precipitation. |
| 關鍵字 | Cryolite; Crystallization; Etching solution; Recovery |
| 語言 | en |
| ISSN | 1873-3794;1383-5866 |
| 期刊性質 | 國外 |
| 收錄於 | SCI EI |
| 產學合作 | |
| 通訊作者 | Li, Chi-Wang |
| 審稿制度 | 是 |
| 國別 | GBR |
| 公開徵稿 | |
| 出版型式 | ,電子版,紙本 |
| 相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/99102 ) |