本项目通过研究 Na+, K+, Mg2+//Cl-, SO42--H2O 体系低温（-5至-15 ℃）介稳态相化学关系及冷冻结晶规律，得出该体系低温结晶过程的基础热力学和动力学数据。探明硫酸盐(亚)型低品位盐湖钾矿溶解行为和规律，解释固液转化和平衡机理，并提出高效分离方法，为合理利用硫酸盐(亚)型低品位盐湖钾矿和老卤资源提供依据；结合介稳态相关系、结晶动力学、热力学以及溶液性质，全面反映五元体系低温下的性质，为五元卤水体系析出固相的物相分析和组分的分离提取提供依据，同时为能源利用提供依据；结合DFT及分子动力学方法，研究不同化学环境下的固相析出形式和机理，发展DFT理论及分子动力学方法在液相或固相共存状态时物质结构解析中的应用及多组分卤水体系中的应用。

This project is to study the metastable phase equilibrium and freezing crystallization process of Na+, K+, Mg2+//Cl-, SO42--H2O quinary system (-5 to -15 ℃), and to understand low temperature crystallization mechanism based on thermochemical and kinetic data. The physicochemical properties will help to understand the dissolution behavior of low grade potassium sulfate type (subtype) Salt Lake ore and to explain the mechanism of the solid-liquid transformation, which provides the foundation for efficient separation and rational utilization of low-grade potassium sulfate type (subtype) Salt Lake ore and brine resources. The metastable phase equilibrium data, crystallization kinetics, thermodynamics and solution properties can help us to understand the nature of the quinary system at low temperatures and provide the basis and guidance for extraction/precipitation/solid phase separation of quinary system with efficient energy utilization. DFT and molecular dynamics method will be used to study the formation and mechanism of the solid-phase precipitation under different chemical environments, which will further develop the applications of DFT theory and molecular dynamics methods in structural analysis of substances in liquid and solid phase coexistence brine system and/or multi-component brine system.