A new process for Al2O3 production from low-grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH-NaAl(OH)4 media
文献类型：期刊论文
| 作者 | Ma, Jiayu; Li, Zhibao; Xiao, Qinggui |
| 刊名 | AICHE JOURNAL
 |
| 出版日期 | 2012-07-01 |
| 卷号 | 58期号:7页码:2180-2191 |
| 关键词 | reactive silica kinetic modeling Bayer process stabilization dissolution precipitation |
| ISSN号 | 0001-1541 |
| 其他题名 | Aiche J. |
| 中文摘要 | A new process of Al2O3 production from low-grade diasporic bauxite based on the reactive silica dissolution and stabilization in concentrated NaOH-NaAl(OH)4 solutions is proposed and proved feasible. NaOH and Al2O3 concentrations and leaching temperature were found to be the main factors affecting the leaching process of reactive silica. The A/S (mass ratio of Al2O3/SiO2) of diasporic bauxite was enhanced from 5.4 to 15 by reactive silica removal under the optimum operation conditions. Two obvious steps control the whole leaching process of reactive silica in NaOH-NaAl(OH)4 media: reactive silica dissolution and desilication products (DSPs) precipitation. The kinetics data of two controlling steps fit a shrinking core model based on the calculation of OH- activity with the aid of OLI platform and an empirical kinetic model well, respectively. Apparent activation energies of reactive silica leaching in the temperature range from 80 to 110 degrees C are 101.91 and 58.65 kJ mol-1 for the two steps, respectively. The stabilization mechanism of reactive silica in concentrated NaOH-NaAl(OH)4 solution was also elucidated based on the complexation of aluminum-bearing species and the calculation of supersaturation to DSP. It was found that the concentration of OH- sharply decreases due to the formation of Al(OH)?4- species with increasing aluminum concentration, suppressing greatly DSP precipitation. This proposed process paves the way for Al2O3 production from low-grade diasporic bauxite with high-reactive silica content. (C) 2011 American Institute of Chemical Engineers AIChE J, 2012 |
| 英文摘要 | A new process of Al2O3 production from low-grade diasporic bauxite based on the reactive silica dissolution and stabilization in concentrated NaOH-NaAl(OH)4 solutions is proposed and proved feasible. NaOH and Al2O3 concentrations and leaching temperature were found to be the main factors affecting the leaching process of reactive silica. The A/S (mass ratio of Al2O3/SiO2) of diasporic bauxite was enhanced from 5.4 to 15 by reactive silica removal under the optimum operation conditions. Two obvious steps control the whole leaching process of reactive silica in NaOH-NaAl(OH)4 media: reactive silica dissolution and desilication products (DSPs) precipitation. The kinetics data of two controlling steps fit a shrinking core model based on the calculation of OH- activity with the aid of OLI platform and an empirical kinetic model well, respectively. Apparent activation energies of reactive silica leaching in the temperature range from 80 to 110 degrees C are 101.91 and 58.65 kJ mol-1 for the two steps, respectively. The stabilization mechanism of reactive silica in concentrated NaOH-NaAl(OH)4 solution was also elucidated based on the complexation of aluminum-bearing species and the calculation of supersaturation to DSP. It was found that the concentration of OH- sharply decreases due to the formation of Al(OH)?4- species with increasing aluminum concentration, suppressing greatly DSP precipitation. This proposed process paves the way for Al2O3 production from low-grade diasporic bauxite with high-reactive silica content. (C) 2011 American Institute of Chemical Engineers AIChE J, 2012 |
| WOS标题词 | Science & Technology ; Technology |
| 类目[WOS] | Engineering, Chemical |
| 研究领域[WOS] | Engineering |
| 关键词[WOS] | SPENT BAYER LIQUOR ; ALUMINOSILICATE SOLUTIONS ; DIGESTION CONDITIONS ; SOLUBILITY ; SYSTEM ; DESILICATION ; KINETICS ; MODEL ; BEHAVIOR ; ION |
| 收录类别 | SCI |
| 原文出处 | |
| 语种 | 英语 |
| WOS记录号 | WOS:000304900700019 |
| 公开日期 | 2013-11-28 |
| 版本 | 出版稿 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/6408]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 作者单位 | Chinese Acad Sci, Key Lab Green Proc & Engn, Natl Engn Lab Hydromet Cleaner Prod Technol, Inst Proc Engn, Beijing 100190, Peoples R China |
| 推荐引用方式 GB/T 7714 | Ma, Jiayu,Li, Zhibao,Xiao, Qinggui. A new process for Al2O3 production from low-grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH-NaAl(OH)4 media[J]. AICHE JOURNAL,2012,58(7):2180-2191. |
| APA | Ma, Jiayu,Li, Zhibao,&Xiao, Qinggui.(2012).A new process for Al2O3 production from low-grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH-NaAl(OH)4 media.AICHE JOURNAL,58(7),2180-2191. |
| MLA | Ma, Jiayu,et al."A new process for Al2O3 production from low-grade diasporic bauxite based on reactive silica dissolution and stabilization in NaOH-NaAl(OH)4 media".AICHE JOURNAL 58.7(2012):2180-2191. |
入库方式： OAI收割
来源：过程工程研究所
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