Abstract Electrowinning is an important process to extract Ni from aqueous solutions. In this work, the characteristics of electro-deposited Ni were modified by employing magnetic agitation and flowing bubbles in an acidic chloride solution. The nucleation and growth of Ni grains were analyzed in the electro-crystallization. Phase compositions and morphologies of the modified deposits were characterized. As well, the positive effects of magnetic agitation and flowing bubbles on the electrowinning process were discussed. Mass transportation of Ni2+ ions was efficiently accelerated by magnetic agitation and upwards flowing bubbles. The preferential growth of Ni deposit was also facilitated along the (111) orientation. The nucleation and growth of Ni crystals proceeded in the instantaneous nucleation mode and the lateral growth mode, respectively. The introduction of magnetic agitation and upwards flowing bubbles can promote the detachment of hydrogen gas and be available for the enhancement of current efficiency.

中文翻译：

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Ni在酸性 NiCl2 溶液中电沉积的显微结构改性

摘要 电解沉积是从水溶液中提取镍的重要工艺。在这项工作中，通过在酸性氯化物溶液中使用磁力搅拌和流动气泡来改变电沉积镍的特性。在电结晶过程中分析了Ni晶粒的形核和生长。表征了改性沉积物的相组成和形态。此外，还讨论了磁力搅拌和流动气泡对电解沉积过程的积极影响。Ni2+ 离子的传质通过磁力搅拌和向上流动的气泡有效加速。沿（111）方向也促进了 Ni 沉积物的优先生长。Ni晶体的成核和生长分别以瞬时成核模式和横向生长模式进行。