The effect of additives on anode passivation in electrorefining of copper

Ilkhchi, Mehdi Ojaghi; Yoozbashizadeh, H.; Safarzadeh, M. Sadegh

doi:10.1016/j.cep.2006.10.005

Cited by 34 publications

(18 citation statements)

References 11 publications

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“…Furthermore, the deposition potential shifts in the positive direction in the presence of thiourea. 21,[36][37][38] The depolarization of the cathode at low concentrations of thiourea might be attributed to the adsorption of thiourea and their reactions with Ni 2+ ions and/or Fe 2+ ions. Han et al further reported that some Ni 2+ ions could complex with thiourea to form Ni[CS(NH 2 ) 2 ] 2+ and the formation of this complex favoured the Ni deposition process, 39 thereby leading to depolarization of the cathode.…”

Section: Nucleation Mechanismmentioning

confidence: 99%

Recovery of Ni from the Acid Leaching Solution of Electroplating Sludge through Preparing Ni-Fe Alloy with the Addition of Saccharin Na First and then Thiourea

Wang

2019

Electrochemistry

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A novel method of Ni recovery from the acid leaching solution of electroplating sludge through preparing Ni-Fe alloy with high Fe 2+ content (i.e., 0.5 g/L) is proposed in this paper, and the corresponding electrodeposition process was studied using conventional electrochemical techniques and scanning electron microscopy. The obtained results showed that adding saccharin Na at concentrations from 0 to 14 g/L to the deposition bath increased the cathodic polarization potential of Ni-Fe co-deposition, with sensible grain refinement and disappearance of surface cracks observed after the addition of 14 g/L saccharin Na. Two different mathematical models of metal nucleation were tested, and the different morphologies of the deposits formed with and without saccharin Na suggested disparate nucleation mechanisms. The Ni-Fe deposition potential shifted positively in the presence of thiourea, and it should not be added together with saccharin Na during the nucleation stage for the grain refinement of the deposits. The iron contents in the deposits decreased with the increase of thiourea concentration ascribed to the thiourea complex which adsorbed on the cathodic surface preventing Fe 2+ electrodeposition from the electrolytes.

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Section: Nucleation Mechanismmentioning

confidence: 99%

Recovery of Ni from the Acid Leaching Solution of Electroplating Sludge through Preparing Ni-Fe Alloy with the Addition of Saccharin Na First and then Thiourea

Wang

2019

Electrochemistry

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“…It is known that increasing the current density is expected to result in a higher overpotential, which should increase the nucleation rate [22], thus enhancing the productivity of the electrowinning process [23]. However the current density applied to the electrolysis process is restricted by the limiting current [24], beyond which serious deterioration in the quality of the cathode deposit occurs.…”

Section: Introductionmentioning

confidence: 99%

Effects of temperature and current density on zinc electrodeposition from acidic sulfate electrolyte with [BMIM]HSO4 as additive

et al. 2009

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The effects of temperature and current density on cathodic current efficiency, specific energy consumption, and zinc deposit morphology during zinc electrodeposition from sulfate electrolyte in the presence of 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO 4 ) as additive were investigated. The highest current efficiency (93.7%) and lowest specific energy consumption (2,486 kWh t -1 ) were achieved at 400 A m -2 and 313 K with addition of 5 mg dm -3 [BMIM]HSO 4 . In addition, the temperature dependence of some kinetic parameters for the zinc electrodeposition reaction was experimentally determined. Potentiodynamic polarization sweeps were carried out to obtain the expression for each parameter as a function of temperature. In the condition studied, the exchange current density depended on temperature as ln(i 0 ) = -a/T ? b and the charge transfer coefficient was constant. Moreover, the adsorption of the additive on cathodic surface obeyed the Langmuir adsorption isotherm. The associated thermodynamic parameters indicated the adsorption to be chemical.

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“…Over the last several years, some of our research efforts have been aimed at elucidating passivation mechanism for commercial copper anodes. This has been studied using various electrochemical techniques such as voltammetry [4,5], impedance spectroscopy [6][7][8][9], and chronopotentiometry (polarisation under imposed constant anodic current) [10][11][12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Study of the copper anode passivation by electrochemical noise analysis using spectral and wavelet transforms

Lafront

Safizadeh

Ghali

et al. 2010

Electrochimica Acta

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The effect of additives on anode passivation in electrorefining of copper

Cited by 34 publications

References 11 publications

Recovery of Ni from the Acid Leaching Solution of Electroplating Sludge through Preparing Ni-Fe Alloy with the Addition of Saccharin Na First and then Thiourea

Recovery of Ni from the Acid Leaching Solution of Electroplating Sludge through Preparing Ni-Fe Alloy with the Addition of Saccharin Na First and then Thiourea

Effects of temperature and current density on zinc electrodeposition from acidic sulfate electrolyte with [BMIM]HSO4 as additive

Study of the copper anode passivation by electrochemical noise analysis using spectral and wavelet transforms

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