ADSORPTION OF CYANIDE-CONTAINING SPECIES FROM DICYANOAURATE SOLUTIONSON GOLD ELECTRODEPOSITS

Adsorption of cyanide-containing species from 5 x 10(-6)-5 x 10(-3) M KAu(CN)(2) solutions in alkaline supporting electrolyte (0.1 M K3PO4) on gold electrodeposits was investigated over a wide potential range ( from -1.5 to 1.5 V/SHE) using the radioactive labeling (C-14) method. The results obtained from dicyanoaurate solutions were compared with t hose obtained from cyanide solutions at the same total ligand (cyanide ) concentration. In the potential region between dicyanoaurate reducti on and gold oxidation the adsorption Gamma of cyanide-containing speci es from dicyanoaurate solution lies above that from cyanide solution, but it approaches that from cyanide solution as the rate of cathodic r eduction of dicyanoaurate increases. The adsorption Gamma from cyanide solution approaches that from dicyanoaurate solution as the rate of g old anodic dissolution in cyanide solution increases.