Determination and correlation of solubility of magnesium sulfate in sulphuric acid solution.

The solubility of magnesium sulfate in sulphuric add solution was determined by equilibrium method in the temperature from T = (263.15 to 298. 15 ) K. The results show that the solubility of magnesium sulfate decrease with the decrease of temperature or the increases of sulfuric add concentration. The solubility data was correlated by Apelblat equation, empirical equation. (CNIBS)/ Redlich-Kister equation, and(CNIBS)/Redlich-Kister equation has the best correlation effect, the average relative deviation is 0.41%. The changes of entropy, enthalpy and Gibbs free energy of the dissolving process were obtained by modified Van t-Hoof equation. The results show that the dissolving process of magnesium sulfate was a spontaneous process of endothermic and entropy rincreacing and enthalpy change was the main factor affecting the dissolution process. The experimental results can provide data support for the research of magnesium sulfate removal technology by low temperature crystallization from the waste electrolyte of zinc hydrometallurgy. [ABSTRACT FROM AUTHOR]