Phase formation in the system Na+,Ca2+,Al3+|| SO42–,HCO3--H2O at 273 K

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The article discusses the results of determining possible phase equilibria on geometric images of a five-component mutual water-salt system of sulfates, sodium bicarbonates, calcium and aluminum at 273 K, followed by the construction of its phase complex diagram. The patterns that determine the structure of the phase complex of this system are needed both to obtain scientific data used as reference material, as well as to create optimal conditions for the disposal of liquid waste from industrial aluminum production containing sulfate, bicarbonate salts of sodium, calcium and aluminum. To achieve this goal, we used the translation method, according to which the dimension of the geometric images of the diagram of the original (private) system, when adding a subsequent component to it, increases by one, i.e. the geometric images are transformed. Due to the fact that the studied five-component system consists of five particular four-component systems, the addition of a fifth component to any of them is accompanied by a transformation of the geometric images of all five four-component systems. Transformed geometric images, based on their topological properties, are translated (transferred) to the level of a five-component composition. At the level of a five-component composition, transformed and translated geometric images, observing the Gibbs phase rule, intersect and form geometric images of a given level of component. The study of the phase equilibria of a five-component water-salt mutual system of sulfates, sodium bicarbonates, calcium and aluminum and the construction of its phase complex diagram by the translation method at 273 K showed that it is characterized by the presence of twelve divariant fields, ten monovariant curves and three non-invariant points at this temperature. Based on the data obtained, a complete closed phase diagram of the studied system was constructed for the first time and, for ease of reading, fragmented along the divariant crystallization fields of equilibrium solid phases.