柴达木盆地盐湖镁硼酸盐沉积过程中地球化学行为研究

There are abnormal phenomenon of supersaturation solubility, dilute salify and solubilization of common ion existing for magnesium borate in higher magnesium boron brine system. The special phenomenon is against the principle of classical chemistry, however, there is little in-depth study on the microscopic nature of these special phenomenon. This project used Mg2+//Cl-,borate-H2O and Mg2+// SO42-,borate-H2O simple ternary system as the research object, it is very significant to study the dissolution and transformation mechanism of the high concentration magnesium borate salt in the brine and the effect of solution structure about borate salt by adding magnesium salt. We will accurately measure the metastable and stable phase equilibrium data of systems at 15 ℃, determine the borate ions forms in the process of liquid phase chemical behavior and calculate its mole fraction. we will study of the solution structure of magnesium borate in high concentration magnesium borate brine by using synchrotron radiation X-ray scattering method. This project attempts to further clarify the mechanism of dissolving transformation and crystallization deposition process of magnesium borate, the influence of solution structure about magnesium borate though adding magnesium salt, and realize the connection between macroscopic phase chemical properties and microscopic structure of borate solution. We finally to realize understand the microscopic essence of magnesium borate abnormal phenomenon in the brine, and clarify the formation conditions and mechanism of various magnesium borate mineral, and provide a theoretical foundation for the geochemistry of salt-formation of magnesium borate.

高镁含硼卤水体系中镁硼酸盐存在“过饱和溶解度”、“稀释成盐”以及“同离子增溶”等反常现象，目前针对这种与经典化学原理相悖的特殊现象的微观本质缺乏深入研究。本项目以Mg2+//Cl-,borate-H2O和Mg2+// SO42-,borate-H2O简单三元体系为研究对象，对高浓镁盐卤水中镁硼酸盐溶解和转化过程中溶解转过过程与机制、外加镁盐对硼酸盐溶液结构的影响进行基础科学研究。具体内容包括：测定体系15℃介稳和稳定相平衡数据，确定硼酸根在相化学行为过程中存在形式以及迁移规律，采用同步辐射X射线散射法研究高浓镁盐卤水中镁硼酸盐溶液结构。揭示镁硼酸盐在卤水中的反常现象的微观本质，建立硼酸盐溶液微观结构与宏观相化学性质的联系，为认识高原盐湖，解决各种镁硼酸盐矿物的形成条件与机制这一成盐地球化学难题奠定理论基础。

高镁含硼卤水体系中镁硼酸盐存在“过饱和溶解度”、“稀释成盐”以及“同离子增溶”等特殊现象， 本项目从实验地球化学研究入手，采用等温溶解平衡法实验研究方法和手段，研究了镁硼酸盐在纯水中溶解转化规律，以及镁硼酸盐在高浓镁盐溶解转化、蒸发浓缩过程硼酸根物种随着高浓镁盐浓度变化规律，给出硼在高浓镁盐卤水中高度富集微观机理；采用DTF理论计算了溶液中离子水合结构及Raman光谱。揭示镁硼酸盐在卤水中的反常现象的微观本质，建立硼酸盐溶液微观结构与宏观相化学性质的联系，为认识高原盐湖，解决各种镁硼酸盐矿物的形成条件与机制这一成盐地球化学难题奠定理论基础。已发表或接受论文8篇（SCI 2篇，EI 2篇）。