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The Effect Of Mass Transport On Deposit Quality In Copper Electrowinning, Joseph Bauer
The Effect Of Mass Transport On Deposit Quality In Copper Electrowinning, Joseph Bauer
Doctoral Dissertations
"Roughness and nodulation of copper electrodeposits depend strongly on mass transfer conditions of copper ions to the electrode surface. Mass transfer properties in electrowinning electrolytes were first characterized. The effective diffusivity of cupric ion was measured with a rotating disk electrode in CuSO4-H2SO4 electrolytes at temperatures relevant to electrowinning, with and without additives. Adding 20 mg L-1 of chloride ion increased the measured diffusion coefficient, but commercial smoothing additives had little effect. An empirical formula to predict cupric diffusivity was generated for later use in mass transport modeling.
Boundary layer thickness information for commercial …
Improving Base Metal Electrowinning, Charles Ebenezer Abbey
Improving Base Metal Electrowinning, Charles Ebenezer Abbey
Doctoral Dissertations
"In zinc electrowinning, Mn oxidizes to form MnO2 on Pb-Ag anodes, cell walls and pipes. MnO2 reduces anode corrosion but also leads to short circuits and maintenance issues. MnO2 is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …
Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull
Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull
Doctoral Dissertations
"Electrochemical deposition methods are presented for the deposition of Co(OH)2 and Cu metal. Paper I shows the deposition of β-Co(OH)2 on Ti through electrochemical reduction of [Co(en)3]3+ to [Co(en)3]2+ in 2M NaOH. The catalytic properties of the deposited Co(OH)2 towards water oxidation is found comparable to Co3O4, with the surface of the Co(OH)2 converting to CoOOH during the reaction. Paper II gives the conditions suitable for epitaxial growth of Co(OH)2 on Au(100), Au(110), and Au(111) following the same reduction mechanism as described in Paper I. …