| 题名 | 离子液体在低温电解铝中的应用研究 |
| 作者 | 郑勇 |
| 学位类别 | 博士 |
| 答辩日期 | 2013-04-01 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 张锁江 ; 吕兴梅 |
| 关键词 | 离子液体 铝 低温电解 电化学 |
| 其他题名 | Application of ionic liquids in the low-temperature electrolysis of aluminium |
| 学位专业 | 化学工程 |
| 中文摘要 | 铝是国民经济中重要的基础原料，2012年我国产量已超过1900万吨，是有色金属中最高的。目前电解铝行业仍普遍采用霍尔-埃鲁法进行铝的工业化生产，该法存在着生产温度高、能耗高和温室气体排放量大等问题，急需通过技术革新来予以解决。因此，开发新型低温电解铝新工艺，对实现产业节能减排和社会的可持续发展具有重大的意义。离子液体作为一种新型的低温电解质，在金属电沉积领域有着广阔的应用前景。本文从上述背景出发，系统研究了离子液体低温电解铝反应过程，主要研究内容如下： 1. 设计并合成了[Bmim]Cl/AlCl3、[Emim]Cl/AlCl3、[Amim]Cl/AlCl3、[H1mim]Cl/AlCl3和[Hmim]Cl/AlCl3等具有优良物理化学性能的氯铝酸型离子液体，通过核磁共振、元素分析、质谱、液相色谱、紫外、红外和拉曼光谱对其进行了系统的结构和纯度的表征。 2. 测定了氯铝酸离子液体在不同温度和组成下的密度、粘度和电导率，计算了相应的摩尔电导、偏摩尔体积和粘度偏差。同时结合分子模拟结果，从静电力、范德华力和氢键作用的角度深入研究了离子液体微观结构和宏观性质间的关系。 3. 对氯铝酸型离子液体进行了详尽的电化学表征，分析并讨论了不同条件下离子液体的电化学窗口、化学稳定性、铝的电还原过程、氯气的析出反应和电极界面效应等，建立了系统的电化学数据体系。 4. 以玻璃碳为新型惰性阳极，氯铝酸型离子液体为低温电解质，全面考察了不同实验条件下氯气在玻璃碳上的析出过程，建立并完善了氯气的捕集和阳极效率的测定方法，讨论了电解温度、电位、电流密度和真空度等因素对阳极反应的影响。 5. 在电化学和分子模拟的基础上，深入研究了电解条件、离子结构和相互作用对铝沉积过程的影响，并利用扫描显微镜（SEM）、原子力显微镜（AFM）、X射线衍射（XRD）和X射线能谱（EDAX）等手段对铝产品进行了表征，筛选出了最佳的电解反应条件，获得纯度较高的铝产品，掌握了铝形貌的调控机制。 6. 依据实验研究结果，在广泛的文献调研和实际参观考察的基础上，提出了离子液体低温电解铝的新工艺方案。该工艺结合了无水氯化铝的转化制备、氯铝酸离子液体的合成、大容量电解槽的设计、氯气的回收利用、铝粉的收集清洗以及其它相关的反应步骤，具有很强的可行性和经济性。 |
| 英文摘要 | Aluminium is an important industrial material in the modern world. In 2012, the annual yield of aluminium was more than 19 million tons, which was the largest in the domestic production of nonferrous metals. Since the end of 19th century, the production of aluminium has been mainly conducted by the Hall-Héroult electrolytic process. However, this method suffers from many problems, including high operating temperature, high energy consumption and high CO2 emission. Therefore, it’s necessary to develop new methods for the low-temperature and low-energy electrolysis of aluminium. Ionic liquids (ILs) are labeled as room-temperature molten salts, which have a bright prospect in the low-temperature electrodeposition of metals. In this work, systematic research has been done on the low-temperature electrolysis of aluminium from ILs. The main content of this work is listed as follows. 1. A series of chloroaluminate-based ILs with excellent physicochemical properties, including [Bmim]Cl/AlCl3, [Emim]Cl/AlCl3, [Amim]Cl/AlCl3, [H1mim]Cl/AlCl3, and [Hmim]Cl/AlCl3 were designed and synthesized. All the ILs have been characterized by NMR, MS, HPLC, EA, IR, Raman, and UV spectra, respectively. 2. The densities, viscosities, and electrical conductivities of chloroaluminate-based ILs were measured at different temperatures. The values of molar conductivity, excess molar volumes, and viscosity deviations were obtained. Based on the results of density functional theory calculations, the relationship between these properties have been analyzed from the perspective of molecular structure, cation-anion interaction, and hydrogen bonds. 3. Systematic electrochemical measurements were performed to get a deeper insight into the electrochemical behavior of chloroaluminate-based ILs. The chlorine evolution, aluminium electrodeposition, electrode interfacial reaction, electrochemical windows and chemical stability of ILs were analyzed and discussed in detail. 4. Glass carbon was first employed as novel anode material in the low-temperature electrolysis of aluminium. The chlorine evolution on anode was analyzed at different conditions. Meanwhile, the methods of chlorine capture and anode efficiency measurement have been established. The effects of temperature, potential, current density, and vacuum degree on the anode efficiency were also studied. 5. On the base of electrochemical measurements and density functional theory calculations, the effects of experimental conditions, molecular structure, and cation-anion interaction on the aluminium electrodeposition were analyzed in depth. All the aluminium deposits were characterized by emission scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffractometer (XRD), and energy dispersive X-ray (EDAX). The optimum experimental parameters, regulation mechanism of aluminium morphology, and high-purity products have been obtained. 6. A new process for low-temperature electrolysis of aluminium was proposed based on extensive experimental results, literature research and market survey. The new process mainly includes: the preparation of anhydrous aluminium chloride, synthesis of ILs, design of high-capacitance electrolytic cell, recycle of chlorine, collection and purification of aluminium. In general, the new method has much more advantages in industrial operation and social economy. |
| 语种 | 中文 |
| 公开日期 | 2014-06-26 |
| 页码 | 152 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/8384]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 郑勇. 离子液体在低温电解铝中的应用研究[D]. 中国科学院研究生院. 2013. |
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