中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 18 No. 4 August 2008 |
YIN Zhou-lan(尹周瀾)2, ZHANG Ping-min(張平民)2
（1. Department of Environmental Engineering, Xiamen University of Technology, Xiamen 361024, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract: The preparation of Al(OH)3 by the ion exchange membrane electrolysis followed by the precipitation of sodium aluminate solution with seeds was made. During the process of ion membrane electrolysis, the sodium aluminate solution is rapidly acidified and the caustic ratio (aK) is decreased due to oxygen evolution in the anodic region. And the causticity of solution is increased due to hydrogen evolution in the cathode region, producing the high concentration of caustic soda solution. Regulating the acidity of the anodic solution by controlling the electric quantity in the electrolysis and subsequent decomposing the solution, Al(OH)3 could yield with very large rate and high efficiency. The experiments also indicate that the quality of aluminum hydroxide product is greatly affected by the impurity silicon.
Key words: sodium aluminate solution; ion exchange membrane; electrolysis and precipitation with seeds; silicon
