著者

佐々木 秀顕 二宮 裕磨 岡部 徹

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.136, no.3, pp.14-24, 2020-03-31 (Released:2020-03-31)

参考文献数

170

被引用文献数

1 7

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In the process of electrorefining of copper, application of higher current density increases the tendency of anode passivation. The passivation disrupts the sound operation of the electrorefining process, reducing the current efficiency and the quality of copper deposited on the cathode. Therefore, anode passivation should be avoided in industrial electrolytic cells. Anode passivation is attributed to the precipitation of copper sulfate, which is saturated locally in the vicinity of the anode surface. When a copper anode contains high concentrations of insoluble impurities that form slime on the anode surface, the tendency of anode passivation increases. Because e-waste often contains such elements that induce anode passivation as well as the harmful elements from the concentrate, the operation of the electrorefining process becomes difficult when the feeding ratio of secondary materials (scraps) is increased. To promote the recycling of metals and reduce energy consumpution in the process, it is essential to develop a passivationprevention technology for low-grade copper anodes. This article outlines the physicochemical basis of anode passivation and reviews earlier research with a focus on experimental techniques. Past research on anode passivation of pure Cu anodes, which was carried out to understand the precipitation of copper sulfate quantitatively, is also reviewed to explain the relationship between passivation and current density.

著者

佐々木 秀顕 岡部 徹

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.136, no.7, pp.77-87, 2020-07-31 (Released:2020-07-31)

参考文献数

174

被引用文献数

3

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Over the past years, the significance of recycling Cu and its accompanying metals has been increasing. However, the frequency of anode passivation increases during the electrorefining of copper when the copper anode contains a high concentration of impurities. When the amount of secondary materials (scraps) used is increased, the process of electrorefining is frequently troubled because e-waste contains elements that induce anode passivation. Therefore, the development of passivation-prevention technology for low-grade copper anode is essential. This article reviews previous research on the behavior of impurities in the Cu anode and their effects on passivation. The guiding principles for developing passivation-prevention technology are also outlined.