Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 15 No. 4 August 2005|
（School of Metallurgical Science and Engineering, Central South University,
Changsha 410083, China）
Abstract: Resorting to Debye-Hückel equation, the conception of the apparent dielectric constant ε′ of sodium aluminate solution is introduced. By supposing that all the influences are attributed to it, ε′ is successfully related to caustic ratio αK, concentration mNaOH, T and temperature T. Then an activity coefficient calculation model for NaAl(OH)4-NaOH-H2O system from 25℃ to 100℃ is established, which can be used in much wider αK and mNaOH, T ranges than those covered by the equilibrium solubility data.
Key words: Debye-Hückel equation; activity coefficient; calculation model