engleski

Optimization of Electrochemical Copper Recovery Process: Effect of the Rotation Speed in Chloride Medium of pH=3

Potentiostatic copper electrodeposition at a graphite electrode from synthetic 0.05 M copper (II) sulfate solution was studied at pH 3. Sodium chloride was added to increase the conductivity of the solution and catalyze the process. Cyclic voltammograms had shown that copper was deposited though the two step reduction processes Cu(II)/CuCl and CuCl/Cu(0). The effect of the electrolyte rotation using magnetic stirrer during deposition at -500 mVSCE has been studied. The current efficiency and the copper removal percentage increase with the increase of the rotation speed and at 1500 rpm reached a maximum of 94% and 99% respectively after four (4) hours of process. Without rotation, XRD results illustrate a heterogeneous deposit that consists of pure copper with copper oxide, hydroxide and chloride species. The deposit became more pure with the increase of the rotation speed. SEM results show, that initially, the deposit was compact and uniform while at later deposition times, the structure and morphology changed to delicate deposit characterized by dendritic growth. This deposit was easily removable from the cathode suiting the purpose of copper recovery.

copper recovery; potentiostatic copper electrodeposition; rotation; chloride medium; current efficiency; dendritic growth.

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