High-Temperature Stable Phase Equilibria of Ternary Systems LiBr–NaBr–H2O and LiBr–KBr–H2O

The underground brine in the Sichuan basin is not only widely distributed but also of excellent quality, which has broad prospects for comprehensive development and utilization. Due to the complex geological structure and relatively high air humidity in the Sichuan basin, salt field technology cannot be used for the separation and enrichment of brine resources. Therefore, forced evaporation by external energy can only be used to achieve the purpose of the preliminary separation of salts. In order to realize effective development and utilization of this underground brine resource, it is necessary to carry out multitemperature phase equilibrium research from ambient to high temperature for this brine system. Here, we take lithium-, potassium-, and bromine-rich underground brine in the Sichuan basin as research object and use the isothermal dissolution equilibrium method to research the stable phase equilibria of two ternary systems (LiBr–NaBr–H2O and LiBr–KBr–H2O) under temperature conditions of 373.15, 398.15, and 423.15 K. Based on the experimental results, the corresponding phase diagrams were drawn, and the phase diagrams under different temperature conditions were compared to reveal the phase equilibrium relationship and crystallization–dissolution rules of each component in the above two systems under multitemperature conditions.