【作者】 于青；

【导师】 翟玉春； 刘国强；

【作者基本信息】 东北大学 ， 化学工艺， 2008， 硕士

【摘要】 随着锂离子电池产量和应用的增多,废弃锂离子电池的处理已经成为一个日益迫切的问题。在众多的处理方案中,再生处理是目前的研究热点,同时也是最具发展前途的方案。它不仅可以解决报废锂离子电池所带来的一系列环境问题,而且对电池中有价金属进行回收并循环利用,也有效的缓解了资源的紧张。本论文在探索试验的基础上,针对废锂离子电池组成特点,并结合实际情况,确定了电池放电处理→机械破碎→正负极分离→钴铝分离→硫酸双氧水浸出→钴锂沉淀分离的湿法工艺流程从废锂离子电池中回收有价金属铝、铜、钴、锂等。该工艺设计简单,着眼于实际应用,实现了资源的回收利用,无废物产生,对环境友好。具体的研究内容和取得的成果如下：通过预处理,将单体电池机械破碎,分离开电池正负极,正极材料在450°C焙烧2h,除去粘结剂PVDF,超声振荡2min,将钴酸锂成功从铝箔上分离,回收铝。负级材料在200°C焙烧2h,超声振荡2min,回收铜。在400°C、600°C、800°C的温度下对钴酸锂进行热处理,通过XRD和SEM分析发现,随着焙烧温度的增加,Co3O4含量逐渐增加,LiCoO2颗粒细小均匀,分散性好,易于浸出。对正极活性物质LiCoO2采用硫酸-双氧水体系浸出,成功分离乙炔黑等杂质。在单因素试验的基础上进行正交试验,结果发现：钻和锂的浸出率随着温度的升高、反应时间的增长、硫酸浓度的增加、双氧水加入量的增多而增大。确定最佳的浸出条件为：温度80℃、时间120min、酸氧比4：1、硫酸浓度4mol/L,钴和锂的浸出率达到94.3%。本文还对钻酸锂的浸出反应动力学进行了研究,由实验得出如下结论：(1)根据公式lntc=—mlnc+I,求出酸度影响级数m=0.82,因此钻浸出反应的速度与酸浓度之间的关系可表示为：说明硫酸浓度对Co2+浸取影响较大所得酸浸反应的动力学方程为：lntc=-0.82lncH++3.6812(2)根据公式可得钴浸出反应的表观活化能为17.3kJ/mol,该数值表明,钴浸出反应的控制步骤为扩散步骤。对钴酸锂浸出液中钴和锂离子进行沉淀分离实验,比较了直接合成法和过程络合法沉钴的效果,分别沉淀出α-Co(OH)2和β-Co(OH)2,并在800°C煅烧4h结晶,制备出氧化钴。用饱和的Na2CO3溶液在90℃的温度下沉锂,制备碳酸锂。通过XRD分析发现,制备的氧化钴和碳酸锂产品衍射峰尖锐,纯度较高。整个实验设计工艺简单,效率高,回收彻底,具有较好的应用前景。更多还原

【Abstract】 Disposal of spent lithium-ion batteries(LIBs) have becoming more and more important with the growth of production and use of LIBs. Recycling treatment has attracted more and more attentions. Compared to other methods of treatment, recycling can not only resolves environmental problem, but also slows the lack of resource effectively by recovering and reusing of valued metals from LIBs.In exploration experiment foundation, in view of waste lithium-ion batteries composition characteristic and combining actual situation, the technical process of recycling the valuable metal aluminum, copper, cobalt, lithium etc. from spent lithium-ion batteries is as follows:Battery discharge processing→machinery broken→separation anode and cathode→separation cobalt from aluminum→solution leaching with vitriol and hydrogen peroxide→precipitation and separation cobalt and lithium. This technological design simple, focuses to the practical application, has realized the resources recycling use, the non-waste production, is friendly to the environment. The concrete research contents and obtained achievements are as follows:Through pretreatment, machinery broken monomer battery, divided the battery anode and cathode, the positive electrode material in 450℃roasted 2h, excepted cementing agent PVDF, supersonic vibrated 2min, succeeded separation LiCoO2 from the aluminum foil, recycled aluminum. The cathode material in 200℃roasted 2h, supersonic vibrated 1min, recycled copper. Under 400℃,600℃,800℃temperatures carried on the heat treatment to LiCoO2, through XRD and SEM analysis discovery:Along with the roasting temperature increase, the Co3O4 content gradually increases, LiCoO2 pellet tiny and uniformity, dispersivity good, is easy to leach.With the sulfuric acid-hydrogen peroxide solution system leaching to positive electrode active material LiCoO2, successful separation acetylene black impurity. Carried on the chiasma experiment in the single factor experiment foundation, finally discovered:The cobalt and the lithium leaching rate advanced with the reaction temperature and time growth, the sulfuric acid density and the quantity of the hydrogen peroxide increase. The determination best leaching condition is:The temperature is 80℃, time is 120min, the acid:oxygen is 4:1, sulfuric acid density is 4mol/L, the cobalt and the lithium leaching rate achieved 94.3%.This article also has researched the leaching reaction kinetics of LiCoO2, obtained the following conclusion by the experiment:(1)According to the formula lntc=-mlnc+I, figured out the reaction order of sulfuric acid(m) is 0.82. Therefore between the cobalt leaching response speed and the acid concentration relations may be represented as: Explained it is bigger influence the sulfuric acid density to the cobalt leaching rate,Response dynamic equation is lntc=-0.82 lncH++3.6812.(2) According to the formula figured out the apparent activation energy(E) is 17.3kJ/mol, this value indicated, cobalt leaching response control step is the diffusing step.Carried on the precipitation separation experiment to the cobalt and lithium, wound compared with the direct synthesis and the process legitimately to sink the cobalt effect, separately precipitated alpha-Co(OH)2 and beta-Co(OH)2, and burnt 4h in 800℃, manufactured Co3O4. Sinked the lithium with saturated Na2CO3, manufactured Li2CO3. Through XRD analysis discovery, the Co3O4 and Li2CO3 product diffraction peak is incisive, the purity is higher.The entire experiment designs simply, efficiency high, the recycling is thorough, has the better application prospect.更多还原