Synergistic effect of cupric and ferrous ions on active-passive behavior in anodic dissolution of chalcopyrite in sulfuric acid solutions

Hiroyoshi, Naoki; Kuroiwa, Shigeto; Miki, Hajime; Tsunekawa, Masami; Hirajima, Tsuyoshi

doi:10.1016/j.hydromet.2004.01.003

Cited by 117 publications

(38 citation statements)

References 11 publications

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“…It has been suggested that chalcopyrite forms a passivation layer during dissolution due to produced elemental sulphur [14], recently thought to be produced copper polysulfide [15]. It has also been reported that chalcopyrite dissolution is enhanced significantly within a certain potential window (0.55-0.62 V vs. standard hydrogen electrode) because chalcopyrite is reduced to chalcocite in the presence of copper ions (Equation (10)), and this reduced chalcocite oxidation (Equation (4)) is easier than that of chalcopyrite dissolution [16][17][18].…”

Section: Analysis Of Chalcopyrite Dissolution Mechanicsmentioning

confidence: 99%

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

et al. 2016

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An electrode system to study the mechanism of fine microgram powder sulfide mineral dissolution was developed by using a relatively simple method that enables the attachment of micrograms of fine powder to a platinum plate surface. This system yields highly reproducible results and is sensitive compared with conventional electrode systems for various sulfide minerals such as pyrite, chalcopyrite, chalcocite, enargite, and tennantite. The leaching behavior of chalcopyrite was re-examined in a test of the application of this electrode system. Chalcopyrite dissolution is enhanced in specific potential regions because it is believed to be reduced to leachable chalcocite, but this result is inconclusive because it is difficult to detect the intermediate chalcocite. Powder chalcopyrite in the new powder electrode system was held at 0.45 V in the presence of copper ion and sulfuric acid media followed by an application of potential in the anodic direction. Besides the chalcopyrite oxidation peak, a small peak resulted at ∼0.55 V; this peak corresponds to reduced chalcocite, because it occurs at the same potential as the chalcocite oxidation peak.

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Section: Analysis Of Chalcopyrite Dissolution Mechanicsmentioning

confidence: 99%

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

et al. 2016

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“…This indicates that in addition to the pyrite circuit, another coating layer exists as the Z 2 component, which consists of resistance (R 2 ) and capacitance (CPE2). 22) This calculated circuit allowed the parameters of the EC elements for pyrite samples to be calculated; the values are listed in Table 1.…”

Section: Effect Of Treatment Time Of Silicate Coating On Pyrite Oxidamentioning

confidence: 99%

Silicate Covering Layer on Pyrite Surface in the Presence of Silicon–Catechol Complex for Acid Mine Drainage Prevention

et al. 2015

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In this paper, prevention of pyrite oxidation by carrier microencapsulation (CME) was investigated. A possible layer structure was suggested following analysis with electrochemical and surface analysis techniques. Electrochemical study of treated pyrite samples showed that treatment with siliconcatechol (Si-Cat) for 6 h at an initial pH of 9.5 gave the best barrier properties and suppression of the samples. Scanning electron microscopy with energy-dispersive X-ray, and Fourier transform infrared (FTIR) analyses confirmed the presence of a silicate layer on the surface of treated pyrite. X-ray photoelectron spectroscopy indicated that the coating layers on the treated pyrite samples consisted of a network of Fe-O-Si and Si-O-Si units bonded to the surface of pyrite. The Si-O-C asymmetric stretching mode was also observed in FTIR spectra. Detailed spectroscopic analyses confirmed the formation of a silicate polymer on a silicaquinone layer, which resulted in the effective suppression effect shown by Si-Cat-treated pyrite at increasing pH.

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“…The oxidation can be represented by the equations: [34][35][36][37][38] /CuFeS 2 , on the surface of the CuFeS 2 crystals. This layer actually represents an electrode the potential of which is described by equation (3) for both an aqueous and non-aqueous environment.…”

Section: Mechanism Of the Indicator Pyrite (Chalcopyrite) Electrodementioning

confidence: 99%

Application of Pyrite and Chalcopyrite Electrodes for the Acid-Base Determinations in Nitriles

Simi¹,

Stani²,

Antonijevi³

2011

J. Braz. Chem. Soc.

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Os minerais naturais pirita e chalcopirita tem sido usados como sensores em eletrodos indicadores usando acetronitrila e propionitrila como solventes. Os resultados mostram vantagens excepcionais da pirita e chacopirita como sensores eletroquímicos e também a possibilidade de aplicação desses eletrodos para determinações em solventes não aquosos onde eletrodos de vidro mostram dificuldades. O comportamento dos eletrodos indicadores de pirita e chalcopirita em nitrila foi avaliado pela titulação de diversas bases e ácidos de forças diferentes usando prótons e íons liato gerados pela oxidação de alguns ésteres de ácido gálico e fenóis diidróxi, bem como m-cresol e 3-metóxifenol. Os resultados obtidos com esses eletrodos foram comparados com os de eletrodos de vidro nas mesmas condições, obtendo-se boa concordância, reprodutividade e precisão. Os desvios padrão na determinação dos ácidos e bases investigados foram menores do que 0,9%. Em titulações potenciométricas com pirita e chalcopirita como eletrodos indicadores, o potencial é instantaneamente estabelecido. Ambos os eletrodos podem ser usados sem qualquer limitação temporal ou divergências potenciais consideráveis.The natural minerals pyrite and chalcopyrite have been used as the indicator electrode sensors using acetonitrile and propionitrile as solvents. The results show the exceptional advantage of pyrite and chalcopyrite as electrochemical sensors and also the possibility of the application of these electrodes for the determination in nonaqueous solutions where glass electrode shows many defaults. The behaviour of the pyrite and chalcopyrite indicator electrodes in nitriles were checked by titrating several bases and acids of different strengths using protons and lyate ions generated by the oxidation of some gallic acid esters and dihydroxy phenols, as well as m-cresol and 3-metoxy phenol. The results obtained by using these electrodes were compared with those obtained by the application of a glass electrode under the same conditions, and good agreement, reproducibility and accuracy were obtained. The standard deviation of the determination of the investigated acids and bases was less than 0.9%. In the potentiometric titrations with pyrite and chalcopyrite indicator electrodes, the potential is instantaneously established throughout. Both electrodes can be used without any time limit or without considerable divergence in potentials.

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Synergistic effect of cupric and ferrous ions on active-passive behavior in anodic dissolution of chalcopyrite in sulfuric acid solutions

Cited by 117 publications

References 11 publications

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

Silicate Covering Layer on Pyrite Surface in the Presence of Silicon–Catechol Complex for Acid Mine Drainage Prevention

Application of Pyrite and Chalcopyrite Electrodes for the Acid-Base Determinations in Nitriles

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Synergistic effect of cupric and ferrous ions on active-passive behavior in anodic dissolution of chalcopyrite in sulfuric acid solutions

Cited by 117 publications

References 11 publications

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

The Development of Fine Microgram Powder Electrode System and Its Application in the Analysis of Chalcopyrite Leaching Behavior

Silicate Covering Layer on Pyrite Surface in the Presence of Silicon&ndash;Catechol Complex for Acid Mine Drainage Prevention

Application of Pyrite and Chalcopyrite Electrodes for the Acid-Base Determinations in Nitriles

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Silicate Covering Layer on Pyrite Surface in the Presence of Silicon–Catechol Complex for Acid Mine Drainage Prevention