Electrolytic Copper Deposition from Ammoniacal Alkaline Solution Containing Cu(I)

摘要

In order to verify the feasibility of copper electrodeposition from ammoniacal alkaline solutions containing Cu(I), the cafhodic polarization characteristics of Cu(I) and the galvanostatic electrodeposition from a Cu(I) solution were investigated. The cathodic polarization curve for the 0.5kmolm~(-3) Cu(I)-5 kmol m~(-3) NH3-I kmol m~(-3) (NH_4)SC_2 solution showed an increase in the electric current corresponding to the deposition of copper at around -0.22 V vs. SHE which is much higher than the potential for hydrogen evolution. The current efficiencies for the copper electrodeposition from the Cu(I) solution nominally without Cu(II) were greater than 95 percent in the current density range of 200 to 1000 Am~(-2). A further increase in the current density resulted in a decreased current efficiency due to the hydrogen evolution. The current efficiency decreased with the increasing Cu(II) concentration and temperature. These results indicate that the present copper electrodeposition method is applicable for the new energy-saving hydrometallurgical recycling process.