复合添加剂在交直流叠加电解精炼铜中的电化学行为研究

自制一系列新型复合添加剂,通过大量实验遴选出一种效果较好的复合添加剂,采用三电极体系的动电位法测定了在该添加剂作用下阴极铜沉积循环伏安曲线和交流阻抗曲线图,结合金相显微镜照片,研究其在交直流叠加电解精炼铜中的作用并对其作用机理进行简单的阐述。结果表明:自制复合添加剂具有增极化作用,可以显著改善阴极铜表面质量,但不改变阴极铜沉积反应机理;添加剂存在时,交直流叠加电解在保证阴极铜质量前提下,可以将电流密度提高到360 A/m~2左右;电解时间较长时,交直流叠加电解仍然可以一定程度上改善阴极铜质量。     

Preparation and properties of Al-Mn alloy coatings in NaCl-KCl-AlCl3-CeCl3 molten salts

Al-Mn alloy coatings were electrodeposited on an iron substrate from AlCl3-NaCl-KCl molten salts with anhydrous MnCl2 enhanced by the addition of CeCl3. The microstructure and properties of the Al-Mn alloy coatings were investigated, and scanning electron microscopy, X-ray diffraction, and polarization curves were used to determine the composition, surface morphology, phase structure, and corrosion resistance of the obtained deposits. The results showed that the surface coatings were smooth, and that the crystallites were dense and uniform when 0.22 wt.% CeCl3 was added to the molten salt. An amorphous mixture of Al and Al6Mn was obtained. CeCl3 enhanced the corrosion resistance and increased the hardness of the single amorphous phase alloys. The pitting potential of the coating was approximately -1.1239 V, and its hardness was 390 kgf/mm2.     

溴代氯铝酸离子液体的微波合成及电沉积铝应用

采用新型微波合成方法制备溴代氯铝酸离子液体,测试其物理化学性能,并将其作为电解质应用于铝的电沉积。通过测定循环伏安曲线、计时电流曲线以及极化曲线探讨铝在2AlCl3/[EMIM]Br离子液体中的电沉积机理。室温下在铜基体上进行铝的恒电位沉积,沉积层形貌以及结构特性分别用SEM、XRD进行表征。结果表明:溴代氯铝酸离子液体的新型微波合成与普通微波合成相比,大大缩短了反应时间,提高了产品性能;铝的电沉积为准可逆的动力学行为,沉积过程非单纯的扩散控制而是复杂的动力学限制步骤;铝在不同电位下的沉积层大致分为3种典型形貌,并对各种形貌产生的原因及特征进行分析。