Fundamental study for higher current density operation of copper electrorefining by controlling polarization with fluid flow of electrolyte

为了获得更高的生产率，铜电解精炼需要更高的电流密度操作。由于多种因素的相互影响，控制电极上的传质过程，从而在传质条件明确的情况下获得系统的数据是非常重要的。本研究利用旋转圆盘电极法研究了液体流量对电解过程的影响，因为该装置体积小，易于控制。增加电流密度会增加镀层的极化程度和粗糙度。随着转速的提高，极化减小，表面变平。杂质元素的加入改变了电极在高电流密度下的电极电位，即使在电极旋转的情况下也是如此。胶水的加入增加了极化与流体流动的平整度，使表面平坦。

A higher current density operation of copper electrorefining is desired to achieve the higher productivity. It is important to control the mass transfer on the electrodes and hence to acquire systematic data under the clear conditions of the mass transfer because many factors of electrolysis mutually affect each other. In this research, effects of fluid flow on the electrolysis were investigated by using RDE (rotating disk electrode) since the apparatus is small and the control is easy. Increasing the current density increased the polarization and the roughness of the deposit. Increasing the rotation speed decreased the polarization and made the surface flat. The additions of impurity elements changed the electrode potential in the high current density even with the rotation of the electrode. The addition of glue increased the polarization even with the fluid flow and achieved the flat surface.