METHOD FOR ELECTROLYTICALLY REFINING NONFERROUS METAL

To provide the method for electrolytically refining the nonferrous metal, that can prevent nonuniform current distribution in an electrolytic tank brought about by an increase in electrical resistance due to a reduction in a contact area of a contact part between a cathode beam and a bus bar.SOLUTION: The method for electrolytically refining the nonferrous metal comprises a step of flat-polishing the contact part 2b of cathode beams 2 used in an electrolytic operation using an abrasive material whose thickness does not change when polishing the contact part of the cathode beam while pressing the abrasive material, as a result, the contact part between the contact part 2c of a plurality of the cathode beams 2 and the contact part 11a of the bus bar 11 has an average contact area of 10 mmor more, and the contact area of the contact part has a standard deviation σ of 3 mmor less. Preferably, the method further comprises a step of measuring the contact area using a pressure-sensitive paper after flat-polishing.SELECTED DRAWING: Figure 5 【課題】カソードビームとブスバーとの接触部の接触面積の縮小に伴う電気抵抗の増大に起因する、電解槽内における電流分布の不均一化を防止する。【解決手段】電解操業で使用済みのカソードビーム２の接点部２ｂを、研磨材を押し付けながら研磨する際に、厚さが変化しない研磨材を用いて、平面研磨し、複数のカソードビーム２の接点部２ｃとブスバー１１の接点部１１ａとの接触部の平均接触面積が１０ｍｍ２以上、かつ、前記接触部の接触面積の標準偏差σが、３ｍｍ２以下となるようにする。平面研磨後において、前記接触面積を、感圧紙を用いて測定する工程をさらに備えることが好ましい。【選択図】図５