氯化锂溶液中钾离子的吸附分离研究  

Study on adsorption of potassium ions in lithium chloride solution

作　　者：祝增虎[1,2] 王敏 彭正军[1,2] 贾国凤 李燕[1,2] ZHU Zenghu;WANG Min;PENG Zhengjun;JIA Guofeng;LI Yan(Key Laboratory of Green and High-end Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China;Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province,Xining 810008,China)

机构地区：[1]中国科学院青海盐湖研究所,盐湖资源绿色高值利用重点实验室,青海西宁810018 [2]青海省盐湖资源化学重点实验室,青海西宁810018

出　　处：《无机盐工业》2024年第6期61-66,118,共7页Inorganic Chemicals Industry

基　　金：青海省重点研发与转化专项(2021-GX-117)。

摘　　要：作为初级原料的氯化锂产品因钾、钠、钙等杂质含量过高,直接影响了氯化锂及由氯化锂制备的金属锂的应用和系列产品的开发。采用静态吸附法研究了由水热法合成的硅铝酸盐分子筛在氯化锂溶液中对钾离子的吸附分离性能,考察了接触时间、温度、不同钾离子初始浓度、溶液pH、离子强度等对分子筛吸附钾离子的影响,研究分析了分子筛对钾离子的吸附动力学和吸附热力学。结果表明:分子筛对钾离子有较高的选择吸附性且吸附速率快,在溶液初始钾离子浓度为0.005 mol/L、温度为25℃的条件下,30 min后分子筛对钾离子的吸附量为56 mg/g,接近吸附平衡容量;溶液中初始钾离子浓度、离子强度直接影响着分子筛对钾离子的平衡吸附量。通过动力学及热力学分析得知,分子筛对钾离子的吸附更符合Freundlich吸附等温模型且为放热反应,低温有利于吸附的进行;吸附反应过程符合准二级动力学模型,吸附反应速率由多个控制步骤共同决定。同时,分子筛对钾离子有较好的解吸效率,可循环吸附。Lithium chloride products,as primary raw materials,have been affected in their application,as well as in the development of metal lithium and series products prepared due to the high content of potassium,sodium and calcium.The adsorption of potassium ions in lithium chloride solution containing sodium was studied by static adsorption experiments using hydrothermal synthesis of silicoaluminate molecular sieves.The effects of contact time,temperature,initial potassium concentration,pH and ionic strength on adsorption of potassium ions by molecular sieves were investigated.The adsorption kinetics and thermodynamics of potassium ions by molecular sieves were studied and analyzed.The results showed that molecular sieves had selective adsorption for potassium ions with fast rate,the adsorption capacity reached to 56 mg/g after 30 min at the conditions of initial potassium concentration 0.005 mol/L and 25 ℃,which was close to adsorption equilibrium capacity.Initial potassium concentration and ionic strength had a great impact on adsorption equilibrium capacity of potassium ions by molecular sieves.Based on the analysis of thermodynamics and kinetics,the adsorption of potassium ions by molecular sieves was exothermic reaction and conformed to the Freundlich adsorption isotherm model.Low temperature was benefical for adsorption.The adsorption process followed a quasi second order kinetic model and adsorption arte was determined by multiple control steps together.In addition,molecular sieves showed better desorption efficiency and re-adsorption capacity for potassium ions.

关 键 词：分子筛 吸附 钾离子 氯化锂溶液 

分 类 号：TQ131.11[化学工程—无机化工]