Cui Ruizhi, Peng Changwei, Nie Guoliang, Sang Shihua, Ren Hongbao, Li Wu
Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, China.
Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, China.
Front Chem. 2023 Feb 15;11:1093435. doi: 10.3389/fchem.2023.1093435. eCollection 2023.
In view of the composition characteristics of lithium, calcium and bromine rich in Nanyishan oil and gas field brine of western Qaidam Basin, Qinghai Province, as well as based on the results reported in relevant literature, the phase equilibrium relationship of ternary system LiBr-CaBr-HO at 298.15 K was studied by isothermal dissolution equilibrium method. The equilibrium solid phase crystallization regions, as well as the compositions of invariant point, in phase diagram of this ternary system were clarified. On basis of the above ternary system research, the stable phase equilibria of quaternary systems (LiBr-NaBr-CaBr-HO, LiBr-KBr-CaBr-HO and LiBr-MgBr-CaBr-HO), as well as quinary systems (LiBr-NaBr-KBr-CaBr-HO, LiBr-NaBr-MgBr-CaBr-HO and LiBr-KBr-MgBr-CaBr-HO) were further carried out at 298.15 K. According to the above experimental results, the corresponding phase diagrams at 298.15 K were drawn, which revealed the phase relationship of each component in solution and the law of crystallization and dissolution, and meanwhile summarized changing trends. The research results of this paper lay a foundation for further research on the multitemperature phase equilibria and thermodynamic properties of lithium and bromine containing high-component brine system in later stage, and also provide basic thermodynamic data for guiding the comprehensive development and utilization of this oil and gas field brine resource.
针对青海省柴达木盆地西部南翼山油气田卤水中富含锂、钙、溴的组成特点，并基于相关文献报道的结果，采用等温溶解平衡法研究了三元体系LiBr-CaBr₂-H₂O在298.15 K时的相平衡关系。明确了该三元体系相图中的平衡固相结晶区域以及无变量点的组成。在上述三元体系研究的基础上，进一步开展了四元体系（LiBr-NaBr-CaBr₂-H₂O、LiBr-KBr-CaBr₂-H₂O和LiBr-MgBr₂-CaBr₂-H₂O）以及五元体系（LiBr-NaBr-KBr-CaBr₂-H₂O、LiBr-NaBr-MgBr₂-CaBr₂-H₂O和LiBr-KBr-MgBr₂-CaBr₂-H₂O）在298.15 K时的稳定相平衡研究。根据上述实验结果绘制了298.15 K时相应的相图，揭示了溶液中各组分的相态关系以及结晶和溶解规律，同时总结了变化趋势。本文的研究成果为后期进一步研究含锂溴高组分卤水体系的多温相平衡及热力学性质奠定了基础，也为指导该油气田卤水资 源的综合开发利用提供了基础热力学数据。
