西藏湖区现场热溶冷结晶法提钾实验研究

Study on Potassium Extraction Using Hot-Dissolving and Cooling Crystallization Process in Tibet Lake Scene

本文以西藏当雄错盐湖为例,基于湖区独特的地热资源和冷资源,采用热溶冷结晶法在现场对日晒蒸发卤水获得的钾石盐矿进行分离提纯实验研究。实验考察了三个热溶温度和三个冷却温度。结果表明,热溶冷结晶法可以显著提高氯化钾的品位,当冷却温度一定时,热溶温度越高,氯化钾的分离提纯效果越好。同时,以Na+、K+/Cl--H2O三元体系相图为理论指导,讨论和验证了湖区现场自然条件下的热溶变温冷却实验结果,进一步明确了工艺优化的方向,为我国西藏高原碳酸盐型盐湖卤水钾资源的开发利用提供基础数据和工艺参考。

Based on the unique geothermal and cold weather resources of Dangxiongcuo salt lake, this paper em- ployed a hot-dissolving and cooling crystallization process to separate and to purify sylvite from in situ natural evap- oration brine samples. Three hot-dissolving temperatures and three cooling temperatures were investigated sepa- rately in the experiment. The results showed that the process of hot-dissolving and cooling crystallization could sig- nificantly increase the grade of KC1, and that the higher the hot-dissolving temperature, the better the separation and purification effect of KCl, when the cooling temperature is constant. Under guidance of the ternary system phase diagram Na＋ , K＋/Cl-H2 O, this paper discussed how cooling temperature under natural condition of the lake affects the experiment results, and pointed out the further direction to optimize the process. The research results provide data and process references for development and utilization of potassium resource from brine of carbonate- type salt lakes in Tibet, China.