塩化物系I価銅浴からのCu電析における不純物の共析挙動

概要

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The codeposition behavior of impurities such as Ag, Bi, Fe, Ni, Pb and Sb with Cu was investigated galvanostatically at 5-3000A/m2 using Pt cathode at 60 °C in acidic copper ( I ) chloride (cuprous chloride) solution of pH1-2 containing 1.0 mol/L of Cu+ and 4.9 mol/L of Cl-. The impurities were classified into two groups ; group I (Ag, Bi) which codeposits with Cu as metal ; group II (Fe, Ni, Pb, Sb) which is slightly involved in deposited Cu as nonmetal from electrolyte. Ag and Bi of group I behaved as more noble metal than Cu, which showed the typical feature of regular type codeposition. When Cu deposited dendritically, the content of Ag and Bi in deposit increased with increased duration of electrolysis by decreasing net current density due to increased cathode area. The current efficiency for Cu deposition in impurity-free solution was 95-100% over 100-1000A/m2 and abruptly decreased above 1000 A/m2 when the limiting current density of Cu was attained. Although Fe, Ni, Pb and Sb of group II were involved by 0.01-0.02mass% in deposit, they had no influence on the current efficiency and morphology of Cu.
社団法人資源・素材学会の論文
2007-01-25