Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

In a recently published series of papers on mathematical modelling of salt purification by recrystallization, the microcomponent distribution was assumed to follow the homogeneous distribution law Y = k_HX, where X and Y are the mean masses of the microcomponent per unit mass of the macrocomponent in the liquid and solid phases, respectively, and k_H is the analytically determined distribution coefficient of the microcomponent. From the physical point of view, it is more rigorous to assume the validity of an equation of the form Y = k_H^*X, where Y and X are the masses of the microcomponent per unit mass of the macrocomponent at the surface of the solid phase and in the solution, respectively, and k_H^* is the homogeneous distribution coefficient relating to the equilibrium between the microcomponent and macrocomponent in the solution and at the crystal surface (whereas the analytically determined k_H relates to the equilibrium with respect to the bulk of the crystals). This paper presents a simple relationship between the empirical coefficients of the two equations, permitting the recrystallization process to be described by means of the original simple equation using analytically determined component concentrations.