Leaching of Chalcopyrite with Sodium Hypochlorite

Garlapalli, Ravinder K.; Cho, Eung Ha; Yang, Ray Yeng

doi:10.1007/s11663-009-9328-x

Cited by 10 publications

(8 citation statements)

References 7 publications

(7 reference statements)

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“…The leach activation energy, in the absence of the initial addition of Fe 3+ , was found to be 80 ± 10 kJ mol À1 and 84 ± 10 kJ mol À1 for Cu and Fe, respectively, suggesting that the leaching process is chemical reaction controlled, which is in general agreement with the rate limiting step reported by Al-Harasheh et al (2005) and Garlapalli et al (2010).…”

Section: Discussionsupporting

confidence: 89%

“…The rate of chalcopyrite dissolution is increased in the presence of strong and/or high concentrations of oxidants (Palmer et al, 1981;Lin et al, 1986;Antonijevic et al, 2004;Aydogan et al, 2006;Garlapalli et al, 2010) and at high temperatures (Hackl et al, 1995;Al-Harahsheh et al, 2008;Sokic et al, 2009). It is clear that temperature is one of the key factors that directly affects chalcopyrite dissolution kinetics with a considerable number of studies having been reported (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cu and Fe chalcopyrite leach activation energies and the effect of added Fe3+

Kaplun

Kawashima

et al. 2011

Geochimica et Cosmochimica Acta

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Cu and Fe chalcopyrite leach activation energies and the effect of added Fe3+

Kaplun

Kawashima

et al. 2011

Geochimica et Cosmochimica Acta

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“…Equation ( 4) is the predominant reaction in acidic solutions with elemental sulfur as the main product while thiosulfate (reaction similar to (5)) has been proposed as occurring in ammoniacal solutions (pH 9 to 10) (Moyo et al, 2015). The formation of sulfate (equation 6) has been observed and used for analysis of leach data in alkaline (pH 12 to 13) solutions containing hypochlorite (Garlapalli et al, 2010) and is therefore most likely in strongly alkaline solutions. Other iron oxides such as FeO and Fe 3 O 4 are also possible products and reaction (7) has been written in terms of the former.…”

Section: Thermodynamicsmentioning

confidence: 99%

“…(Velásquez-Yévenes et al, 2010, 2010a, 2010bNicol, 2018;Moyo et al, 2018Moyo et al, , 2019 but only chloride has been applied in heap leach practice (Velásquez-Yévenes et al, 2010). Following a paper some years ago (Garlapalli et al, 2010) on the oxidation of chalcopyrite in sodium hydroxide solutions by hypochlorite, a recent paper on the same topic (Choubey, 2018) has renewed interest in a possible two-step process in which oxidation in alkaline solutions is followed by dilute acid leaching of the oxidation residue to selectively leach the copper. However, these publications did not address the fundamental aspects of the alkaline oxidation of chalcopyrite that is the focus of this study.…”

Section: Introductionmentioning

confidence: 99%

The electrochemistry of chalcopyrite in alkaline solutions

Nicol

2019

Hydrometallurgy

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This paper summarizes the results of a study of the anodic characteristics of chalcopyrite in alkaline hydroxide and carbonate solutions. The cathodic reduction of oxygen, peroxide and hypochlorite have also been investigated as possible oxidants in a two-stage process for the heap leaching of chalcopyrite under alkaline conditions.Mixed potential measurements of chalcopyrite in alkaline solutions showed that the reactivity of the common oxidants is in decreasing order hypochlorite > peroxide > oxygen >> chlorate.Anodic oxidation of chalcopyrite involves active oxidation at low potentials followed by a passivation peak and transpassive oxidation at higher potentials. The kinetics of oxidation is favoured by increasing pH in both hydroxide and carbonate solutions. The formation of solid products of oxidation does not prevent continued oxidation for up to 18 hours at potentials below the peak. Coulometric measurements suggest that both thiosulfate and sulfate ions are produced by oxidation in sodium hydroxide solutions while thiosulfate is the main product in carbonate and bicarbonate solutions.At potentials close to the mixed potentials, the rate of reduction of hypochlorite is approximately first-order in hypochlorite concentration and is greater at low hydroxide ion concentrations. The rate of the cathodic reduction of peroxide is also greater at lower pH values but is complicated by the surface catalysed disproportionation of peroxide to water and oxygen.Rates of oxidation of chalcopyrite by both hypochlorite and peroxide in sodium hydroxide solutions have been estimated. The rates in hypochlorite are an order of magnitude greater than those in peroxide solutions and are of the same order of magnitude as those previously measured for the dissolution of chalcopyrite in ammoniacal solutions with copper(II) ions as the oxidant.

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“…[8][9][10][11][12][13] Various other oxidizing agents were investigated as well, such as hydrogen peroxide, ammonium persulfate, hypochlorite and ozone. [14][15][16][17] All these studied processes can leach copper to some extent, but there are some disadvantages. In sulfate media, the leaching kinetics are generally slow (several months) and the leaching of copper is difficult to be complete, due to the formation of passivation layers on the surface of chalcopyrite, such as solid sulfur and iron precipitate (e.g.…”

Section: Introductionmentioning

confidence: 99%

Solvometallurgical process for extraction of copper from chalcopyrite and other sulfidic ore minerals

Monnens

et al. 2020

Green Chem.

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Extraction of copper from sufidic ores, either by pyrometallurgy or hydrometallurgy, has various limitations. In this study, a solvometallurgical process for the extraction of copper from sulfidic ore minerals (chalcopyrite, bornite, chalcocite and digenite) was developed by using an organic lixiviant (FeCl 3 as oxidizing agent and ethylene glycol (EG) as organic solvent). All the studied copper sulfide minerals could be leached efficiently with a FeCl 3 -EG solution. Other lixiviant systems, namely CuCl 2 -EG, FeCl 3 -ethanol and FeCl 3 -propylene glycol could also extract copper, but they did not perform as well as the FeCl 3 -EG solutions. The mechanistic study of chalcopyrite leaching in FeCl 3 -EG solutions confirmed that the leaching products of chalcopyrite were FeCl 2 , CuCl and solid elemental sulfur, where the Fe(II) and Cu(I) were quantified by UV-Vis absorption spectroscopy and solid sulfur was identified by powder XRD. A kinetic study showed that the leaching process was a surface chemical controlled process and the apparent activation energy was calculated to be 60.1 kJ mol −1 . Subsequently, electrodeposition of copper from the pregnant leachate was investigated, and SEM-EDX analysis showed that uniform cubic crystalline deposits of pure copper were produced. Meanwhile, the Fe(III) was regenerated by oxidizing Fe(II) at the anode, with a Morgane membrane in between two electrode compartments to prevent the transfer of Fe(III) to the cathode. Finally, a closed-loop solvometallurgical process was designed with three operational steps: leaching, electrodeposition and removal of Fe(II). The regeneration of the FeCl 3 -EG solution and the use of EG contribute to the sustainability and the greenness of the process.

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Leaching of Chalcopyrite with Sodium Hypochlorite

Cited by 10 publications

References 7 publications

Cu and Fe chalcopyrite leach activation energies and the effect of added Fe3+

Cu and Fe chalcopyrite leach activation energies and the effect of added Fe3+

The electrochemistry of chalcopyrite in alkaline solutions

Solvometallurgical process for extraction of copper from chalcopyrite and other sulfidic ore minerals

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