基于选择性电渗析技术的盐湖卤水镁锂分离试验研究  

Experimental Study on Magnesium Lithium Separation in Salt Lake Brine Based on Selective Electrodialysis Technology

作　　者：杨金花 孙永耀 赵霞 YANG Jinhua;SUN Yongyao;ZHAO Xia(Qinghai Salt Lake Magnesium Industry Co.Ltd.,Geermu 816000,China)

机构地区：[1]青海盐湖镁业有限公司,青海格尔木816000

出　　处：《化学与粘合》2025年第2期192-197,共6页Chemistry and Adhesion

摘　　要：镁锂分离作为提取锂离子的主要手段,其回收率一直处于较低水平,为此,提出基于选择性电渗析技术的盐湖卤水镁锂分离试验研究方法,详细阐述了选择性电渗析技术所需设备以及具体应用,构建二维传质稳态模型,计算出溶液中离子浓度,并用大量实验模拟分离方法的最终效果,通过数据证明选择性电渗析技术可以高效地完成镁锂分离,不同浓度下单位能耗增加的幅度基本相同,其中,在电压达到1.0 V时,三种浓度的样本的单位能耗分别达到了0.003 9 k W/mol、0.004 2 k W/mol、0.004 5 k W/mol,而在镁锂分离系数和锂离子回收率方面,分离试验循环时间70 min是个分水岭,在此之前每种样本下锂离子的回收率均会随着电压增长而增大,增长差别较小,并且增长速度较慢,在70 min后,两者大幅度增加,其中5 V和6 V电压下镁锂分离系数和锂离子回收率高于3 V、4 V条件下的镁锂分离系数和锂离子回收率,在5 V和6 V条件下,达到100 min时,镁锂分离系数为137.2和137.4,锂离子回收率达到了96.7%和97.7%,说明电压的增加有助于盐湖卤水镁锂分离,但是5 V和6 V增幅效果差异较小。Magnesium lithium separation,as the main method for extracting lithium ions,has always had a low recovery rate.Therefore,a research method for magnesium lithium separation in salt lake brine based on selective electrodialysis technology is proposed.The required equipment and specific applications of selective electrodialysis technology are elaborated in detail,a two-dimensional mass transfer steady-state model is constructed,the ion concentration in the solution is calculated,and a large number of experiments are conducted to simulate the final effect of the separation method.The data prove that the selective electrodialysis technology can efficiently complete the separation of magnesium and lithium,and the unit energy consumption increases by the same amplitude with different concentrations.When the voltage reaches 1.0 V,the unit energy consumption of the samples with 3 different kinds of concentration reaches 0.0039 kW/mol,0.0042 kW/mol and 0.0045 kW/mol respectively.In terms of the separation coefficient of magnesium lithium and the recovery rate of lithium ion,the separation test cycle time of 70 min is a watershed.Before this,the recovery rate of lithium ion of each sample will rise with the increase of voltage,and the growth difference is small,and the growth rate is slow.After 70 min,the two will increase significantly.Among them,the magnesium-lithium separation coefficient and Li-ion recovery rate at 5 V and 6 V voltage are higher than those at 3 V and 4 V.When the time is 100 min,at 5 V and 6 V,the magnesium-lithium separation coefficient is 137.2 and 137.4,and the Li-ion recovery rate is 96.7%and 97.7%respectively.The results show that the increase of voltage is helpful for the separation of magnesium lithium in salt lake brine,but the difference of the increase effect between 5 V and 6 V is small.

关 键 词：选择性电渗析技术 盐湖卤水 镁锂分离试验 镁锂分离系数 镁锂比 

分 类 号：TS396[轻工技术与工程]