硫酸镁亚型盐湖卤水高温蒸发析盐结晶规律

摘要

The evaporating crystallization of the magnesium sulfate subtypes brine of Dalangtan Salt Lake in Qinghai Province of China has been investigated .The results showed that the se‐quence of crystallization behavior was MgSO4 ・H2 O ,NaCl ,MgSO4 ・6H2 O ,KCl・MgCl2 ・6H2 O and other salts during evaporating process with temperature varying from 102 ℃ to 122℃ .Based on the analysis of liquid phase compositions and X‐ray diffraction ,we found that the optimal evaporating temperature was 117 ℃ .At this point ,the mass fraction of SO2 -4 was low‐er than 2% and the system could be simplified as Na+ ,K+ ,Mg2+ //Cl- —H2 O quaternary system which meets the requirement of the exploitation of potassium chloride process .These findings provide theoretical foundation for the comprehensive exploitation and utilization of the Dalangtan Salt Lake brine .%针对青海大浪滩盐湖区硫酸镁亚型盐田卤水进行了高温蒸发结晶规律的研究，结果表明该盐田卤水在102～122℃高温蒸发时析盐顺序为：MgSO4・H2 O、NaCl、MgSO4・6H2 O、KCl・MgCl2・6H2 O和其他混盐。通过对不同温度下的液相组分分析和固相X射线衍射分析表明，利用高温蒸发开采此种卤水时，最适宜的蒸发温度应控制在117℃左右。此时，该卤水组成中SO2－4的质量分数低于2％，同时K＋还未析出，可以简化为Na＋，K＋， Mg2＋／／Cl－— H2 O四元体系，以便达到开采氯化钾的工艺需求，为该盐湖卤水的综合开发利用提供理论参考。