The Applicability of Debye-Hückel Model in NaAl(OH)4-NaOH-H2O System

Focusing on the most important NaAl(OH)4-NaOH-H2O system in the industry of alumina production, the feasibility of establishing a calculation model of activity coefficients according to Debye-Hückel theory via the equilibrium solubility data of sodium aluminate solution is discussed in this paper. Firstly, the hypotheses for applying Debye-Hückel theory into NaAl(OH)4-NaOH-H2O system are involved and the values of parameters are determined. Then the applicability of Debye-Hückel model in NaAl(OH)4-NaOH-H2O system is testified. The results indicate that Debye-Hückel model is applicable to the establishment of calculation model of activity coefficients in NaAl(OH)4-NaOH-H2O system and the value of ?NaAl(OH)4 is estimated as 0.3595 nm.