制镁原料盐湖老卤蒸发过程实验研究

为了充分利用青海丰富的镁资源，以25 ℃ Na+，K+，Mg2+//Cl--H2O四元水盐体系相图为理论指导，对察尔汗团结湖高镁卤水净化工艺蒸发过程进行实验研究，考察了高镁卤水蒸发过程杂质的析盐规律。在高镁卤水蒸发结晶过程中，以1 L高镁卤水母液为基准，当蒸发水量到达307 g时，液相中氯化镁含量达到33.697%（质量分数），氯化钠含量可降至0.007%（质量分数），氯化钾含量可降至0.134%（质量分数），镁含量升高了3.412%，钠含量下降率达到91.86%，钾含量下降率达到19.28%。实验结果表明，蒸发结晶过程能使氯化镁溶液浓度提高，杂质离子K+、Na+和少量Ca2+被分离，起到高镁卤水初步净化作用，为制备高附加值镁系列产品的原料提供基础实验依据。

Study on evaporation process of salt lake brine raw material of magnesium products

In order to fully use magnesium resource in salt lake of Qinghai,under the guidance of the equilibrium phase diagram of the system Na+,K+,Mg2+∥Cl——H2O at 25℃,studies on evaporation process in the purification of bittern with high magnesium content from Cha Erhan salt lake were carried out and the crystallization law of impurities in the process of evaporation was also studied.Taking 1 L high-magnesium brine mother liquor as a standard,when the evaporated water was 307 g,the content of magnesium chloride reached 33.697%(mass fraction),the content of sodium chloride reduced to 0.007%(mass fraction),the content of potassium chloride reduced to 0.134%(mass fraction) and the content of magnesium increased by 3.412%.Decreasing rates of sodium content and potassium content were 91.86% and 19.28%,respectively.Results showed that the process of evaporation crystallization increased the concentration of magnesium chloride,separated Na+,K+,and Ca2+,purified bittern with high magnesium content,and provided experimental basis for preparing series high value added magnesium products.