Abstract
The adsorption behavior of a trace of copper as impurity in cyanide baths for silver plating was studied by means of a radioactive tracer. The authors selected 64CuCN as a labelled compound and added it in the cyanide baths for silver plating.
The following results were obtained for the adsorption behavior of copper on the cathode surface in electrode reaction process:
(1) The adsorption of copper in stationary baths increased with the increase in copper concentration.
(2) The adsorption abruptly increased at a current density of 2A/dm2, and it was about 100 times as lage as that of at 1.5A/dm2.
(3) The adsorption increased with the rise in bath temperature.
(4) The adsorption occurred within the thickness of about 8000Å of the electrodeposited silver; accordingly, it was not occlusion in the electrodeposited silver, nor incorporation with the crystal structure.
