Electrochemical modeling and study of copper deposition from concentrated ammoniacal sulfate solutions

Giannopoulou, Ioanna; Panias, Dimitrios; Paspaliaris, Ioannis

doi:10.1016/j.hydromet.2009.06.009

Cited by 29 publications

(13 citation statements)

References 30 publications

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“…Peak A at −450 mV (vs Ag/AgCl) corresponds to a reduction of Cu(II)/Cu(I), whereas peak B at −150 mV (vs Ag/AgCl) corresponds to a reduction of Cu(I)/Cu(0). These results are similar to the results obtained by other researchers in studies on the electrochemical behaviour of copper/ammonium solutions (Giannopoulou et al, 2009;Koyama et al, 2006;Vazquez-Arenas et al 2007).…”

Section: Resultssupporting

confidence: 92%

Determination of the potential gold electrowinning from an ammoniacal thiosulphate solution applied to recycling of printed circuit board scraps

et al. 2015

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The use of electrochemical techniques in the selective recovery of gold from a solution containing thiosulphate, ammonia, and copper, obtained from the leaching of printed circuit boards from mobile phones using ammoniacal thiosulphate, are shown in this work. First, cyclic voltammetry tests were performed to determine the potential of electrodeposition of gold and copper, and then, electrowinning tests at different potentials for checking the rates of recovery of these metals were performed. The results of the cyclic voltammetry show that copper deposition occurs at potentials more negative than -600 mV (Ag/AgCl), whereas the gold deposition can be performed at potentials more positives than -600 mV (Ag/AgCl). The results of electrowinning show that 99% of the gold present in solutions containing thiosulphate and copper can be selectively recovered in a potential range between -400 mV (vs Ag/AgCl) and -500 mV (vs Ag/AgCl). Furthermore, 99% of copper can be recovered in potentials more negative than -700 mV (vs Ag/AgCl).

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Section: Resultssupporting

confidence: 92%

Determination of the potential gold electrowinning from an ammoniacal thiosulphate solution applied to recycling of printed circuit board scraps

et al. 2015

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“…The linearized forms of pseudo-first order and pseudo-second order kinetic models are shown by Eqs. (7) and (8) respectively, where k 1 (min −1 ) and k 2 (L μmol −1 min −1 ) are rate constants of adsorption, q t (L μmol −1 ) is the adsorption capacity at time t, q e (L μmol −1 ) is the equilibrium adsorption capacity.…”

Section: Adsorption Kineticsmentioning

confidence: 99%

“…To deal with these problems, various conventional methods have been developed to eliminate colorants from industrial effluents. They include reduction followed by chemical precipitations [8], ion exchange [9], inverse osmosis [10], coagulation and flocculation [11], oxidation or ozonation [12], membrane separation [13] and adsorption on activated commercial charcoal [14,15]. Most of these methods are however expensive, especially when applied to effluents with high flow rates or high concentration of dyes.…”

Section: Introductionmentioning

confidence: 99%

Comparative assessment of methylene blue biosorption using coffee husks and corn cobs: towards the elaboration of a lignocellulosic-based amperometric sensor

et al. 2019

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The ability of coffee husks (CHs) and corn cobs (CCs) as biosorbents for methylene blue (MB) was investigated in batch mode. The energy dispersive X-ray spectroscopy was used for the determination of elemental composition of both biosorbents. Sorption experiments were carried out as a function of temperature, pH and MB initial concentration. Adsorption capacities of both materials significantly increased with the MB initial concentration. Among the various kinetic and adsorption isotherm models, the experimental adsorption data were best fitted in pseudo-second-order kinetic model and Langmuir isotherm model. The maximum adsorption capacities at room temperature were found to be 79.60 and 73.16 mg g −1 for CHs and CCs respectively. Moreover, the great affinity of MB towards CHs led to deep electrochemical experiments shown that CHs can be used as prominent modifier for a carbon paste electrode (CPE). The linear dynamic range of MB was found within the concentration range of 1-125 µmol/L with a detection limit (3σ) of 3 μM. The elaborated sensor was successfully applied for the determination of adsorption capacities of CHs placed into a column for MB biosorption in river water, suggesting that CH-CPE could be an efficient tool for MB detection in environmental samples.

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“…On the other hand, the electrodeposition of copper from ammoniacal solutions onto substrates other than iron has been studied extensively. Based on thermodynamic and electrochemical studies, numerous authors agree that the electrodeposition of copper from ammoniacal solutions of different compositions occurs via the reduction of cupric tetrammine to cuprous diammine, which is then further reduced to metallic copper (Darchen et al, 1997;Giannopoulou et al, 2009;Graham et al, 2002;Grujicic and Pesic, 2005;Nila and González, 1996a;Nila and González, 1996b;Ramos et al, 2001;Vazquez-Arenas et al, 2007a;Vazquez-Arenas et al, 2007b). The direct reduction of cupric tetrammine to metallic copper is also thought to take place at more negative applied potentials (Grujicic and Pesic, 2005).…”

Section: Introductionmentioning

confidence: 99%

The passivation of iron in ammoniacal solutions containing copper (II) ions

D'Aloya

Nikoloski

2012

Hydrometallurgy

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In the present study it was found that the presence of millimolar amounts of copper (II) ions in ammoniacal solutions leads to the spontaneous formation of a stable passive layer on metallic iron and iron alloys with nickel and cobalt, under conditions in which they would otherwise remain in active dissolution. This finding may be of significance to industrial processes which employ ammoniacal solutions to leach metal values from materials rich in metallic iron, such as, for example, laterite ores which have undergone a reductive pre-treatment.The spontaneous passivation is found to take place regardless of the presence or practical absence of dissolved oxygen, and occurs more readily the higher the copper concentration and the lower the ammonia-ammonium bicarbonate concentration, though it does not take place in ammonia-free aqueous solutions of similar copper (II) ion concentrations.Electrochemical and scanning electron microscopy / energy dispersive X-ray spectroscopy (SEM/EDX) investigations conducted as part of this study showed that the observed passivation is promoted by the cementation of copper onto the actively dissolving iron surface, and subsequently by its re-dissolution. Such process is thought to create favourable conditions which promote the formation of a stable passive layer on the iron surface.

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Electrochemical modeling and study of copper deposition from concentrated ammoniacal sulfate solutions

Cited by 29 publications

References 30 publications

Determination of the potential gold electrowinning from an ammoniacal thiosulphate solution applied to recycling of printed circuit board scraps

Determination of the potential gold electrowinning from an ammoniacal thiosulphate solution applied to recycling of printed circuit board scraps

Comparative assessment of methylene blue biosorption using coffee husks and corn cobs: towards the elaboration of a lignocellulosic-based amperometric sensor

The passivation of iron in ammoniacal solutions containing copper (II) ions

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