摘要
青海盐湖卤水锂资源储量丰富,高镁锂比卤水存在镁锂分离难的问题。基于非平衡动态降温过程中不同盐组分结晶行为存在差异的原理,开展了强制分离高镁锂比卤水的研究,考察了卤水镁锂比、降温速率、流体状态和卤水温度对镁锂分离效果的影响,并分析了结晶过程中镁锂分离的介稳性特点。结果表明,通过非平衡动态降温结晶析出MgCl_(2)·6H_(2)O,可以实现卤水脱镁和镁锂分离,当降温速率为-1.25℃/min、卤水温度在70℃至50℃范围内,镁锂比在10∶1~80∶1时,镁锂分离因子最高可达到1.876,结晶的MgCl_(2)·6H_(2)O纯度最高为99.42%。非平衡动态降温结晶工艺相较于经典的盐田工艺,最多可将锂损失率从模拟盐田工艺的38.39%降至7.56%。该工艺为盐湖卤水镁锂分离提供了一条新的思路,也为后续高纯锂盐的制备奠定了基础。
Qinghai salt lake brine with rich lithium resources,and high magnesium-lithium ratio has the problem of difficult separation of magnesium-lithium from the brine.Based on the principle of the difference in crystallization behavior of different salt components during the non-equilibrium dynamic cooling process,this paper carried out a study on the forced separation of brine with a high magnesium-lithium ratio,and investigated the effect of brine magnesium-lithium ratio,cooling rate,fluid state and brine temperature on the separation of magnesium-lithium.The effect and the metastability characteristics of magnesium-lithium separation during the crystallization process were analyzed.The results show that by non-equilibrium dynamic cooling and crystallization to precipitate MgCl_(2)·6H_(2)O,brine demagnesium and magnesium-lithium separation can be realized.When the cooling rate is-1.25℃/min,the brine temperature is in the range from 70℃to 50℃,the magnesium-to-lithium ratio is 10∶1 to 80∶1,the maximum separation factor of magnesium and lithium can reach 1.876,and the maximum purity of crystallized MgCl_(2)·6H_(2)O is 99.42%.Compared with the classic salt field process,the non-equilibrium dynamic cooling crystallization process can reduce the lithium loss rate from 38.39%of the simulated salt field process to 7.56%at most.This process provides a new idea for the separation of magnesium and lithium from salt lake brine,and also lays a foundation for the subsequent preparation of high-purity lithium salts.
作者
张成卓
成怀刚
李琳琳
薛芳斌
李恩泽
ZHANG Cheng-zhuo;CHENG Huai-gang;LI Lin-lin;XUE Fang-bin;LI En-ze(Institute of Resources and Environmental Engineering,Shanxi University,Taiyuan,030006,China;College of Chemical Engineering,Qinghai University,Xining,810016,China)
出处
《盐湖研究》
CAS
CSCD
2023年第1期59-66,共8页
Journal of Salt Lake Research
基金
国家自然科学基金(U20A20149,51874194,21908137)
山西省研究生教育创新项目(2021Y139)。
关键词
盐湖卤水
分离
非平衡
动态
结晶
Salt lake brine
Separation
Non-Equilibrium
Dynamic
Crystallization
