Yun-Yun Gao,Xiao-Feng Guo,Lan-Rong Zhao,Shi-Hua Sang
The stable phase equilibria of the ternary system MgBr2 + SrBr2 + H2O at 288 and 308 K were studied with the isothermal dissolution equilibrium method. The compositions of solutions and solid phases have been determined and the equilibrium solid phases at the invariant points were identified with the aid of the X-ray diffraction method. The phase diagrams of this system at 288 and 308 K were both constructed in terms of experimental results. Two stable phase diagrams show that this system is hydrate type I at two temperatures without formation of a solid solution or complex salt. Both the phase diagrams are composed of one invariant point, two univariate curves, and two crystallization regions (SrBr2·6H2O and MgBr2·6H2O). The equilibrium solid phases of the invariant point at 288 and 308 K are both SrBr2·6H2O and MgBr2·6H2O, respectively. Combining the Pitzer single-salt parameters of MgBr2 and SrBr2 reported in the literatures, the unreported mixing ion-interaction parameters θMg,Sr and ΨMg,Sr,Br at 288 and 308 K were fitted with the measured values in this study using the Pitzer equations. The agreement between the experimental values and calculated results in the ternary system MgBr2 + SrBr2 + H2O at 288 and 308 K shows that the parameters fitted with solubilities are reliable.
Cui Rui-Zhi,Nie Guo-Liang,Ren Hong-Bao,Yang Qiu-Ye,Li Wu
Based on mother liquor rich in lithium, strontium and bromine obtained from the brine of underground oil–gas field in Qaidam Basin after pre-treatment, the isothermal dissolution equilibrium method was used to study the stable solid–liquid equilibria and phase diagrams of the quinary system LiBr − NaBr − KBr − SrBr 2 − H 2 O and its subsystems at 298.15 K. The solubilities of solids in each system were determined, respectively, and the equilibrium solid phases were determined. In order to clearly reflect the regularities and characteristics of phase equilibria of multi-component systems, the corresponding phase diagrams were also plotted and analyzed. The Pitzer model for the quinary system was parameterized by using relevant experimental thermodynamic data. The solubilities of solids in this quinary system and its subsystems were calculated and compared with experimental results. The results not only help to reveal the thermodynamic behavior of relevant bromides in the process of brine concentration, but also provide some theoretical support for the comprehensive utilization of its brine resources.
危险品化学品经营许可证（带存储）