溶析结晶用于盐湖卤水提钾和镁锂分离研究  

Study on dissolution crystallization for extraction of potassium and separation of magnesium and lithium from salt lake brine

作　　者：成春春[1] 李玉龙[2,3,4] 张志强 刘雪菁[1] CHENG Chunchun;LI Yulong;ZHANG Zhiqiang;LIU Xuejing(College of Chemical engineering,Qinghai University,Xining 810016,China;Qinghai Geological Survey Institute,Xining 810012,China;Key Laboratory of the Northern QinghaiTibet Plateau Geological Processes and Mineral Resources,Xining 810012,China;Engineering and Technology Center of Remote Sensing Big Data in Qinghai Province,Xining 810012,China)

机构地区：[1]青海大学化工学院,青海西宁810016 [2]青海省地质调查院,青海西宁810012 [3]青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012 [4]青海省遥感大数据工程技术研究中心,青海西宁810012

出　　处：《无机盐工业》2024年第6期34-39,共6页Inorganic Chemicals Industry

基　　金：青海省自然科学基金项目(2023-ZJ-712);国家自然科学基金项目(21968026)。

摘　　要：采用溶析结晶法快速分离盐湖卤水中氯化钾并降低卤水中的镁锂比,解决青海盐湖盐田摊晒存在的生产周期长、需要修建大面积盐田等难题。以有机溶剂为溶析剂,考察了不同种类溶析剂加入量、溶析温度、溶析时间等对盐湖氯化钾收率及镁锂比的影响。实验结果表明,以无水乙醇为溶析剂与盐湖卤水体积比为2∶1,溶析温度为-15℃,时间为90 min时,氯化钾和氯化钠的收率分别达到93.15%和99.84%。溶析结晶后的母液经过过滤,在70~80℃,以0.5℃/min的降温速率进行动态降温,析出氯化镁晶体,镁锂质量比由原卤中的388.44降低至266.63,最终达到快速分离氯化钾的目的及为后续对镁锂进一步分离提供更有利的条件。In order to solve the process difficulties of extracting potassium from salt lakes in Qinghai and extracting lithium from high magnesium lithium ratio salt lake brine,the dissolution crystallization method was used to extract potassium from salt lakes and reduce the magnesium lithium ratio.The effects of different types of solvents,such as addition amount,dissolution temperature,and dissolution time,on the yield of potassium chloride and the magnesium lithium ratio in salt lakes were investigated using organic solvents as dissolution agents.The results showed that when anhydrous ethanol was used as the dissolution agent,with volume ratio of 2∶1 to salt lake brine,dissolution temperature of-15 ℃,and dissolution time of 90 min,the yields of potassium chloride and sodium chloride reached 93.15% and 99.84%.The mother liquor was filtered at 70~80 ℃ and cooled dynamically at cooling rate of 0.5 ℃/min to precipitate magnesium chloride crystals.The mass ratio of magnesium to lithium was decreased from 388.44 to 266.63.Finally,the rapid separation of potassium chloride was realized and it provided more favorable conditions for the further separation of magnesium and lithium.

关 键 词：溶析结晶 氯化钾 高镁锂比 盐湖卤水 镁锂分离 

分 类 号：TQ131.13[化学工程—无机化工]