Complementary electrochemical and spectroscopic techniques were used to characterize the behavior and composition of the passive layer formed at the gold-thiosulfate interface in the presence of copper. Raman studies of three different cationic (calcium, ammonium and sodium) thiosulfate leaching solutions showed that the concentrations of sulfate, thiosulfate, trithionate and tetrathionate remained constant.
Initial leaching current densities for the three systems were identical, however, significant differences were noted in the open circuit potentials of these systems. Gold nanorod electrodes were employed as substrates for Surface Enhanced Raman Spectroscopy (SERS) studies of the gold-thiosulfate interface. The composition and behavior of the passive layer at the gold- thiosulfate interface greatly differed from that of the bulk solutions. Higher order polythionate species were not observed, and significant differences were noted in the behavior of species common between the three thiosulfate leaching solutions. Passivation levels determined from SERS indicate that in the presence of copper, the cation associated with thiosulfate may play a key role in the extent of passivation on the gold surface. / Barrick Gold Corp., NSERC
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/6463 |
| Date | 19 April 2013 |
| Creators | Nicol, Eric |
| Contributors | Lipkowski, Jacek |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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