Prediction of phase equilibria in multicomponent water-salt systems by means of translation method

Abstract

The translation method which can produce all the geometrical figures and closed phase equilibria diagram for multicomponent water-salt systems was described. The phase equilibria in quinaryNaCl - KCl -MgCl2 - CaCl2 - H2O (25°C) system which is an important part of the more complex oceanic Na, K, Mg, Ca//Cl, SO4- H2O system were determined using translation method. Three invariant points of quadruple saturation, tenmonovariant curves of triple saturation and twelvedivariant fields of double saturation salts were identified in the system. Two of the curves extend between the quinary invariant points while the other eightare generated from extension of the relevant quaternary invariant points into the quinary composition. A total phase equilibria diagram for the quinary NaCl - KCl - MgCl2 - CaCl2 - H2O system at 25°C was constructed on the basis of obtained results. The diagram was fragmented into divariant fields of common crystallization of two salts. A good agreement was observed between the results obtained in this work and the available data in literature.

Phase equilibria in the Na,Ca//SO4,CO3,HCO3-H2O system at 0 °C

“…Transformed geometric images have formed correspond-ing phase diagram components on the n+1 level, according to their topological properties (fields, curved, points), taking into account the Gibbs phase rule for the n+1 component system. More detailed description of the translation method that can be used for predicting and constructing of equilibrium phase diagrams for the multicomponent water -salt systems are considered in the works [3][4][5]. Previously, this method was used to study the fivecomponent system [6].…”

Phase complex of the system Na,Ca||SO4,CO3,HCO3-H2O at 100 ºC

“…We have deduced phase equilibria in the Na,Ca||SO 4 ,CO 3 ,HCO 3 -H 2 O system at 100 °C using translation methods [4,5] which follows from the principle of compatibility of structural elements of n and n + 1 component systems in one diagram [6,7]. According to the translation method, the addition of one more component to the n-component system and its transition to the n + 1 component state is accompanied by transformation of the geometric image of the n-component system.…”

“…The transformed geometric images are translated to the n + 1 level according to their topological property in accordance with the Gibbs phase rule, forming correspondent geometric images (fields, curves, points) in the n + 1 component system. The application of translation methods for predicting and constructing phase diagram for multicomponent water-salt systems was considered in more details in our previous work [4]. Earlier this method was successfully used for other multicomponent systems [8,9].…”

Phase equilibria in the sea-water Na, K, Mg//Cl, SO4–H2O quinary system at 0 °C

“…It has been observed that the structures of Janecke diagrams of multicomponent water-salt systems can be obtained by means of translation method, which is more comprehensively described in literature (Soliev 1987(Soliev , 2000. For instance, the part saturated with sylvite forms a crystallization volume of sylvite that can be extracted from the phase equilibria diagram constructed by means of the translation method.…”