| dc.contributor.author | Jarjoura, George. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:24Z | |
| dc.date.available | 2004 | |
| dc.date.issued | 2004 | en_US |
| dc.identifier.other | AAINR02125 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/54720 | |
| dc.description | To increase production in copper electrorefining operations higher current densities are desirable. Unfortunately, too high current densities may cause anode passivation i.e. stoppage of the electrorefining process altogether. The presence of nickel and oxygen in the anode and in the electrolyte has long been suspected as contributing to copper anode passivation. | en_US |
| dc.description | A 3-electrode arrangement cell was used to investigate the effect on copper anode passivation of the presence of nickel in the anode and in the electrolyte. Anodes with 0, 1, 2, 3, 4, 5, and 6 w% nickel and known oxygen content were prepared in an induction furnace, under argon/7% vol H2 atmosphere in cylindrical boron nitride crucibles. The anodes were then homogenized for 10 hours at a temperature of 950°C, under an argon/7% vol H2 atmosphere and were tested using linear sweep voltammetry (LSV), chronopotentiometry (CP) and cyclic voltammetry (CV) in a cell approved by ASTM using an EG&G model 273A potentiostat controlled by Labview(TM) software. Electrochemical impedance spectroscopy (EIS) was conducted in a specifically designed three-electrode flat cell using the potentiostat and a Frequency Response Analyzer (FRA). | en_US |
| dc.description | The results indicate that an increase in the nickel content of the copper anode caused the samples to passivate in shorter times. It was also found that as the nickel ion concentration in the electrolyte increases from 10, 20, 30, and 40 g/L, the time to passivate the sample is decreased. | en_US |
| dc.description | Cyclic Voltammetry studies showed that the passivation of the samples was affected by the presence of nickel in the electrolyte as well as the anode. In conjunction with XRD it was shown that as the nickel concentration in the electrolyte increased the passive layer changed in nature. Cu2O was observed on the inside layer and CuSO4·5H2O and NiSO4·6H2O were observed on the outer layer when the nickel concentration was at 10 and 20 g/L. Conversely, mostly CuO on the inside layer and CuSO4·5H2O and NiSO 4·6H2O on the outer layer were found when the nickel concentration was at 30 and 40 g/L. | en_US |
| dc.description | The EIS data indicated that nickel in the anode as well as the electrolyte had an effect on the electrical properties of the passivation layer. Nickel in the electrolyte decreased the capacitance of passivation layer, whereas nickel in the anode caused changes in the capacitance of the Passivation layer.* (Abstract shortened by UMI.) | en_US |
| dc.description | *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2004. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Engineering, Metallurgy. | en_US |
| dc.title | Electrochemical investigation of copper/nickel alloys in copper sulfate solution containing nickel using LSV, CP, CV, and EIS. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
