西台吉乃尔盐湖盐田与模拟蒸发过程卤水钾、锂的损失研究

Study on potassium and lithium resource loss in brine of West Taijinar Salt Lake and simulated evaporation process

目前,西台吉乃尔盐湖的基本生产工艺路线是卤水经过盐田蒸发进行自然浓缩,然后利用钾盐结晶阶段析出的钾混盐、光卤石及蒸发后期残留的富锂老卤加工生产钾、锂产品,但收率均不高。通过盐田固-液相定点取样观测和模拟蒸发实验的设计,对西台吉乃尔盐湖卤水蒸发过程中钾锂损失的情况进行对比研究。结果表明,卤水中钾在富集达20 g/L时开始析出钾混盐矿,锂则在此过程中不断富集,由0.19 g/L浓缩至2.12 g/L,蒸发实验结果基本符合盐田实际生产情况。根据实验结果估算盐田中不同阶段的钾、锂损失,得出钠盐田中钾损失率约为12.3%,钾盐田中钾总回收率约为84.4%;锂在钠盐阶段损失率约为6.50%,在钾混盐阶段损失率约为11.59%,在光卤石阶段损失率约为6.21%,在老卤阶段损失率约为6.44%,锂在盐田系统中总损失率约为30.74%,其中在钾混盐结晶阶段锂损失量最大。

At present,the basic production process route of West Taijinar Salt Lake is that brine is naturally concentrated by evaporation in the salt field,and potassium and lithium products are produced by using potassium mixed salt,carnallite and residual lithium⁃rich old brine in the later stage of evaporation,but the yield is not high.The loss of potassium and lithium in the evaporation process of West Taijinar Salt Lake brine was compared and studied by on⁃site solid⁃liquid phase sampling observation and simulated evaporation experiment.The results showed that the potassium in the brine was en⁃riched to more than 20 g/L,and the potassium mixed salt ore began to precipitate.Lithium was continuously enriched in this process,from 0.19 g/L to 2.12 g/L.The evaporation experiment results were basically in line with the actual production of the salt field.According to the experimental results,the loss of potassium and lithium in different stages of salt field was esti⁃mated.The loss rate of potassium in sodium salt field was about 12.3%,and the total recovery rate of potassium in potassium salt field was 84.4%.The loss rate of lithium was about 6.50%in the sodium salt stage,11.59%in the potassium mixed salt stage,6.21%in the carnallite stage,and 6.44%in the old brine stage.The total loss rate in the salt field system was about 30.74%,and the lithium loss in the potassium salt crystallization stage was the largest.