黏土型锂矿中锂的浸出实验研究

黏土型锂矿是一类重要的锂资源,目前关于该类锂矿的研究相对较少。采用氯化铁溶液对碳酸盐黏土型锂矿中的锂元素进行浸出,研究了焙烧温度、氯化铁质量分数、浸出温度和反应时间对锂浸出率的影响。结果表明,氯化铁溶液对样品中的锂元素有较好的选择性浸出作用。当焙烧温度为600 ℃,氯化铁质量分数为15%,浸出液固比为5 mL/g,浸出温度为80℃,反应时间为240 min,转速为240 r/min时,锂浸出率可达82.78%。浸出前后样品的XRD和SEM分析表明,锂的浸出可能是氯化铁溶液中的铁离子与黏土样品中的锂离子进行交换的结果。     

磁性锂离子筛的制备及提锂性能研究

在Stober法的基础上采用二氧化硅对Fe_3O_4包覆钝化,使锂锰氧化物在二氧化硅界面生长,陈化、过滤、烘干、煅烧后生成Li_(1.6)Mn_(1.6)O_4@SiO_2@Fe_3O_4纳米锂离子筛前驱体。酸浸抽锂后得到磁性锂离子筛。SEM结合EDX测试表明,锂锰尖晶石相对均匀地包覆在钝化后的磁核表面,磁性离子筛的平均粒径为18.6nm。在配制的模拟卤水中,H_(1.6)Mn_(1.6)O_4对锂的平衡吸附量是8.78 mg/g,本文制备的H_(1.6)Mn_(1.6)O_4@SiO_2@Fe_3O_4对锂平衡吸附量可达6.01mg/g,除了Mg~(2+)平衡吸附量达到5.213 mg/g以外,其它离子的吸附量都在1.756mg/g以下,说明材料对Li~+的吸附有较好的选择性。用磁性锂离子筛开展反复吸附、脱附试验10次后,其对Li~+仍有良好的吸附效果,平衡吸附量稳定在5.1mg/g,锂解吸率在95%左右。磁性锂离子筛的饱和磁化强度为15.14emu/g,矫顽力为63.02G,可在外加磁场作用下实现与卤水的磁分离。     

磷酸铁锂正极粉选择性提锂

废旧磷酸铁锂电池中，Li具有非常高的经济回收价值。采用无机盐Fe₂(SO₄)₃浸出体系、Fe₂(SO₄)₃-H₂O₂协同浸出体系从废旧磷酸铁锂极片粉中选择性回收锂，考察了浸出剂种类、反应时间、温度、液固比、浸出剂添加量及氧化剂种类等对选择性浸出Li的影响。结果表明：硫酸铁浸出体系液固比5 mL/g,添加1.5倍原料的硫酸铁，在20℃下浸出反应20 min, Li浸出率为91.19%,P浸出率仅为0.02%;硫酸铁-过氧化氢协同浸出体系液固比5 mL/g,反应温度20℃,Fe₂(SO₄)₃添加量为原料的0.6倍，反应20 min后，加过氧化氢调pH至4.1～4.6,Li浸出率可达99.09%,P浸出率为0,Li的选择性浸出效果极好。Fe₂(SO₄)₃-H₂O     

Corrosion of Refractory Alloys in Molten Lithium and Lithium Chloride

Abstract

Several refractory materials have been considered over the years as containment material for lithium and lithium halides. Surface modified refractory metals are being extensively investigated for containment of reactive metals, radionuclides and their compounds. An overview of experimental observations and results of liquid lithium corrosion of selected engineering refractory materials are presented. The nature of the degradation and its mechanism has been explained. The influence of temperature, microstructure, stress, impurities and service time on the corrosion behavior for various refractory alloys have been discussed. Selection rules for materials of containment for liquid lithium and lithium compounds have been suggested. Recent experimental observations on the behavior of tantalum and niobium-based refractory metal alloys in a specific molten salt environment comprising LiCl/Li₂O/Li/Li₃N at 725^°C have been included in an effort to select suitable materials for molten salt equipment. It has been observed that oxygen contamination is particularly harmful for the refractory metal alloys where as nitrogen is deleterious to iron-based alloys.     

从黏土型锂矿中高效浸出锂的研究

采用焙烧—酸浸的方法从某Li_2O品位为0.64%的黏土型锂矿中浸出锂,考察了焙烧时间和焙烧温度对Li_2O浸出率的影响,利用正交试验研究了酸浸工艺中浸出温度和时间、硫酸浓度和液固比对Li_2O浸出率的影响。结果表明,黏土型锂矿在600℃焙烧30min后,锂焙烧渣在浸出温度90℃、浸出时间30min、硫酸浓度1.5mol/L、浸出液固比为6的条件下搅拌浸出,Li_2O浸出率最高达92.97%,浸出效果良好。     

Corrosion of Refractory Alloys in Molten Lithium and Lithium Chloride

Several refractory materials have been considered over the years as containment material for lithium and lithium halides. Surface modified refractory metals are being extensively investigated for containment of reactive metals, radionuclides and their compounds. An overview of experimental observations and results of liquid lithium corrosion of selected engineering refractory materials are presented. The nature of the degradation and its mechanism has been explained. The influence of temperature, microstructure, stress, impurities and service time on the corrosion behavior for various refractory alloys have been discussed. Selection rules for materials of containment for liquid lithium and lithium compounds have been suggested. Recent experimental observations on the behavior of tantalum and niobium-based refractory metal alloys in a specific molten salt environment comprising LiCl/Li₂O/Li/Li₃N at 725°C have been included in an effort to select suitable materials for molten salt equipment. It has been observed that oxygen contamination is particularly harmful for the refractory metal alloys where as nitrogen is deleterious to iron-based alloys.     

磷酸铁锂正极废料选择性提锂制备电池级碳酸锂

废旧磷酸铁锂电池回收对减少环境污染与缓解锂资源压力有重要意义。传统废旧磷酸铁锂电池回收存在锂回收率低、废水处理成本高的问题。通过借鉴Li-Fe-P-H₂O系E-pH图及磷酸铁锂电池充放电脱嵌锂的过程,提出采用“过氧化氢+硫酸”体系选择性回收锂。经XRD、SEM检测,提锂后橄榄石型的FePO₄结构与原始LiFePO₄相结构保持一致,微观形貌的变化也很小。优化条件下,Li浸出率达98%以上,同时Fe、P的浸出率在0.1%以下。得到的锂浸出液经净化后成功制备出电池级的碳酸锂。     

Central South Lithium Plans to Set up Lithium Carbonate Joint Venture

正Recently, Central South Lithium and Tibet Ngari Prefecture Li Yuan Mining Development Co., Ltd. officially entered agreement in Liyang of Jiangsu, which marks their co-founding a joint venture---Tibet Li Neng Lithium Science and Technology Co., Ltd.(shortened as Tibet Li Neng below), a platform on which the both sides operate their businesses. Tibet Li Neng is going to apply its leading technology of "lithium extraction by electrochemical deintercalation" to dealing with salt lakes including Baqiancuo salt lake.     

我国锂资源分布及提取工艺研究现状

介绍了国内锂资源分布及提取锂的方法,着重介绍了从盐湖卤水中提取锂的研究现状,评价了不同提取工艺。结合我国锂资源状况,预测了锂提取技术的研究方向。     

盐湖卤水提锂溶液制备碳酸锂试验

以吸附法盐湖卤水提锂溶液和碳酸钠为原料制备碳酸锂,研究了反应时间、锂质量浓度、反应温度、搅拌速度及洗涤条件对碳酸锂制备的影响。结果表明,以400 g/L碳酸钠溶液为沉淀剂,锂质量浓度18 g/L,反应温度30 ℃,130 r/min速度搅拌,反应1 h可以得到颗粒粒径大且均匀的碳酸锂,锂沉淀率达到85%以上;采用三段逆流、V水/V固=2/1、温度80~90 ℃的水对沉淀洗涤,可得碳酸锂含量99%以上的产品,洗涤过程锂损失2%。     

不同沉淀剂对废旧锂离子电池中锂回收的对比研究

分别采用碳酸钠、磷酸钠和氟化钠为沉淀剂对废旧锂离子电池含锂浸出液进行锂回收的研究。考察了不同沉淀剂加入量、反应温度、反应时间和pH对锂沉淀率的影响规律。结果表明:以碳酸钠和磷酸钠为沉淀剂时,影响锂沉淀率的主要因素是沉淀剂加入量和反应温度,而反应时间和pH对锂沉淀率影响非常小;碳酸钠和磷酸钠沉淀最优化工艺条件下锂的沉淀率分别为70.11%和98.7%。以氟化钠为沉淀剂时,氟化钠加入量是主要影响因素,pH对锂沉淀率的影响较小,而反应温度和反应时间对锂沉淀率几乎没有影响;氟化钠沉淀最优化工艺条件下锂的沉淀率为79.3%。磷酸钠沉锂效果最佳,氟化钠次之,碳酸钠最差。     

废旧磷酸铁锂正极材料氯化焙烧回收锂

针对目前废旧磷酸铁锂处理工艺存在耗能高、污染大等问题,探索了一种废旧磷酸铁锂电池正极材料氯化焙烧工艺。焙烧过程中,以NH₄Cl作为氯化剂,实现锂和部分金属物相转型,形成可溶性的氯化盐。探究NH₄Cl用量、焙烧温度、焙烧时间、气氛条件等对氯化过程的影响。试验结果表明,废旧磷酸铁锂正极材料经氯化焙烧转型,可实现Fe、Al在氧化性气氛中转化为Fe₂O₃、FeOCl和AlPO₄等难溶物,在水浸过程中原料中的不溶性杂质和难溶的Fe、Al化合物进入渣相,Li部分转化为可溶性物质,从而选择性浸出至溶液。本方案能够选择性从废旧磷酸铁锂电池中提取最有价值的金属锂,实现资源的回收、高效利用。     

锂电池正极材料钴酸锂的改性研究进展

概述了锂电池正极材料钴酸锂的结构及改性研究,通过对目前钴酸锂价格昂贵、有毒性、克容量只有理论值的一半等缺点进行分析,叙述了采用掺杂进一步改善钴酸锂性能的方法。     

退役磷酸铁锂正极材料提锂渣资源化回收工艺

目前退役磷酸铁锂正极材料的回收主要是通过选择性浸出回收锂,已实现工业化运行。然而,退役磷酸铁锂正极材料中锂回收后残留的磷铁渣尚未出现有效的处理方法,亟待解决。提出一种盐协助碳热还原—水浸分离法,先通过K2CO3和碳热还原共同作用将FePO4转化为Fe和磷钾化合物,再通过水浸方式将铁和磷分离。系统研究了碳热还原条件对铁磷分离效果的影响。结果表明,在焙烧温度900 ℃、焙烧保温时间4.0 h、K2CO3与磷铁渣质量比0.7、碳粉与磷铁渣质量比0.3的条件下,焙烧产物经常温水浸分离,Fe的回收率为99.3%,水浸固体产物经磁选分离可得到Fe含量为95.2%的产物,实现了磷铁渣中铁与磷的高效分离。本工艺具有不使用强酸、回收过程简单、磷铁渣利用率高等优点,具有工业应用潜力。     

Lithium follow-up in general practice

Lithium salts have been used in medicine for over a century and are a widely accepted treatment. Clinical practice in the London borough of Barnet led us to suspect that agreed guidelines were not being followed. We checked them against published guidelines and followed up their implementation. A list of patients on lithium was obtained from the local biochemistry laboratory and a representative sample extracted. We looked at the frequency of laboratory testing and compared it with the guidelines. We found that the standards for lithium therapy follow-up were not being met and that while we awaited the outcome of our consultant psychiatrists' committee deliberations, the recommendations were not being implemented. A lithium register or clinic needs to be established in the area, and there is also a need for more reliable and effective implementation of clinical audit recommendations.     

锂离子电池电极材料LiCoO_2中锂的分析方法研究

研究建立了锂离子电池电极材料LiCoO2 中主成分Li的分析方法。考察了Li在原子吸收光谱和电感耦合高频等离子发射光谱上的行为。所确定的AAS及ICP AES测定方法准确、简便、快速。Li的RSD 0 .5 8%～ 0 .92 %。加标回收率AAS 98.0 %～ 10 2 .7% ;ICP AES98.6%～ 10 2 .9% ,完全能满足锂离子电池电极材料分析的要求     

Lithium chloride extraction by n-butanol

Lithium chloride extraction with n-butanol has been studied using synthetic solutions containing different quantities of lithium chloride, sodium chloride, potassium chloride and calcium chloride. Based on distribution coefficients, separation factors and McCabe-Thiele representation of the results, a process has been proposed for separation and recovery of lithium chloride. This process has been successfully applied for production of lithium chloride from leach solutions at the laboratory scale. The purity of this lithium chloride product was as high as 99.6%.