自然科学版 英文版
自然科学版 英文版
自然科学版 英文版

您目前所在的位置:首页 - 期刊简介 - 详细页面

中南大学学报(自然科学版)

Journal of Central South University

第35卷    第4期    总第158期    2004年8月

[PDF全文下载]    [Flash在线阅读]

    

文章编号:1672-7207(2004)04-0557-05
高浓度铝酸钠溶液晶种分解动力学
周秋生1,李小斌1,彭志宏1,刘桂华1,赵清杰2,吴 洁3

(1.中南大学冶金科学与工程学院,湖南长沙,410083;
2.中国铝业股份有限公司郑州研究院,河南郑州,450041;
3.中国铝业股份有限公司贵州分公司,贵州贵阳,550058
)

摘 要: 引入瞬时晶种系数Krt,以[(ρ-ρc)/ρf]n2为过饱和铝酸钠溶液晶种分解过程的推动力,导出了高浓度铝酸钠溶液晶种分解过程的动力学方程,得到在高浓度条件下晶种分解过程的表观活化能为30.84 kJ/mol。应用所导出的动力学方程,对分解温度、苛性碱浓度、过饱和度等因素对高浓度条件下晶种分解过程的影响进行模拟分析,研究结果表明:由于该过程的控制方式由铝酸钠溶液较低浓度时的表面化学反应控制转变为高浓度的扩散控制或混合控制,从而导致铝酸钠溶液高浓度时的活化能明显低于其较低浓度时的活化能。

 

关键字: 铝酸钠溶液;浓度;分解;动力学

Kinetics of seeded precipitation from sodium aluminate
solution with high concentration

1.College of Metallurgical Science and Engineering, Central South University, Chang sha 410083, China;
2.Zhengzhou Research Institute, Aluminum Corporation Limited of China, Zhengzhou 450041, China;
3.Guizhou Branch, Aluminum Corporation Limited of China, Guiyang 550058, China

Abstract:By introducing instantaneous seed coefficient and taking [(ρ-ρc)/ρf]n2 as the driving force of the seeded precipitation from sodium aluminate solution with high concentration, a kinetics equation of precipitation including the effects of seed coefficient and super-saturation of solution on the precipitation was deduced in this paper. The obtained apparent activation energy of this process is 30.84 kJ/mol, which is much smaller than that of the sodium aluminate solution with lower concentration reported in literature. The reason is that the controlling process changes from the surface chemical reaction controlling process of the lower sodium aluminate concentration to the diffusion controlling process or the mixed controlling process of the high sodium aluminate concentration. In addition, the influences of temperature, caustic soda concentration and super-saturation on the seeded precipitation were analyzed by the acquired kinetics equation.

 

Key words: sodium aluminate solution; concentration; precipitation; kinetics

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
版权所有:《中南大学学报(自然科学版、英文版)》编辑部
地 址:湖南省长沙市中南大学 邮编: 410083
电 话: 0731-88879765 传真: 0731-88877727
电子邮箱:zngdxb@csu.edu.cn 湘ICP备09001153号