Studies on Phase Equilibria of the Quaternary System LiBr–KBr–SrBr₂–H₂O and Ternary System LiBr–NaBr–H₂O at 323 K

Abstract

Stable phase equilibria of the quaternary system LiBr–KBr–SrBr2–H2O and ternary system LiBr–NaBr–H2O at 323 K were studied by an isothermal dissolution equilibrium method. The solubilities of salts in the two systems were measured experimentally. The equilibrium solid phases at invariant points in these two systems were also identified using X-ray powder diffraction and the Schreinemakers rule. According to the experimental results, the isothermal phase diagrams of the corresponding systems were drawn in detail. The experimental results show that the isothermal phase diagram of the ternary system LiBr–NaBr–H2O at 323 K has two invariant points, three univariate curves, and three single-salt solid-phase crystallization regions, corresponding to LiBr·H2O, NaBr, and NaBr·2H2O. The quaternary system LiBr–KBr–SrBr2–H2O has no double salts and solid solutions. The phase diagram of the quaternary system LiBr–KBr–SrBr2–H2O at 323 K has two invariant points, five univariate curves, and four solid-phase crystallization regions, which are LiBr·H2O, KBr, SrBr2·2H2O, and SrBr2·6H2O. The crystallization region of KBr is larger than those of LiBr·H2O, SrBr2·2H2O, and SrBr2·6H2O, which indicates that KBr has the smallest solubility and is the easiest to be precipitated from the saturated solution. In addition, a comparison of phase equilibria of some similar systems at different temperatures is presented and discussed in detail.

Solid–Liquid Phase Equilibria of Quaternary System LiBr–NaBr–KBr–H2O and Its Subsystems at 348.15 K

“…At present, the studies on stable-phase equilibria of the quaternary system (LiBr–NaBr–KBr–H 2 O) and its ternary subsystems (LiBr–NaBr–H 2 O, LiBr–KBr–H 2 O) under different temperature conditions have been reported in the literature, and the research temperatures are mainly focused on the range of 273.15–323.15 K. ,− Although the reported data are limited, the change characteristics of the equilibrium phase diagram and the change rule of the equilibrium solid phase of this quaternary system and its ternary subsystems can also be seen through the comparison under different temperature conditions. For this reason, this paper lists the liquid-phase compositions and corresponding equilibrium solid phases of the above-mentioned three systems at invariant points, as shown in Table .…”

“… Comparison of equilibrium phase diagrams of ternary system LiBr–NaBr–H 2 O at different temperatures (288.15 K, 24 298.15 K, 19 323.15 K, 26 and 348.15 K). …”

A salting-out strategy for the efficient separation of an azeotropic mixture of allyl alcohol and water

“…12 Salting-out technologies have many advantages, such as energy saving, simple operation, and no need for extractants. [18][19][20] Three high-solubility salting-out potassium salt-based agents (K 2 CO 3 , K 3 PO 4 , and K 4 P 2 O 7 ) showed outstanding salting-out effects in a 1,3-propanediol solution system. 21,22 K 2 HPO 4 has been widely studied as a promising salting-out agent, which can be recovered (acetone + butanol + ethanol) from the prefractionation tower.…”

Solubility Measurement and Calculation of the Quaternary System KCl–KBr–NaCl–NaBr–H2O at 323.15 K

“…Therefore, it is necessary to obtain the relationship between the dissolution equilibrium constant and the solid solution composition when calculating the solubilities . Based on this theory, Weng, , Sang, − Meng et al succeeded in predicting the solubilities of the ternary systems NaCl–NaBr–H 2 O, KCl–KBr–H 2 O, and MgCl 2 –MgBr 2 –H 2 O at 288.15, 298.15, 313.15, 323.15, and 333.15 K. However, it is difficult to determine the composition of the solid solution in a multicomponent system. Relevant reports are limited to experimental results.…”