The dissolution of chalcopyrite in chloride solutions

Nicol, M.J.; Miki, Hajime; Velásquez-Yévenes, Lilian

doi:10.1016/j.hydromet.2010.03.003

Cited by 91 publications

(54 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Ferric iron has been used frequently in chalcopyrite leaching processes under oxidising conditions to increase leach rates [2][3][4][5][6][7]31,33,42,[54][55][56][57]. Fe 3+ can also form via oxidation of Fe 2+ by iron-oxidising microorganisms [4,5,[58][59][60][61][62][63][64][65][66][67][68] or due to the presence of other oxidants such as H2O2 [23,24,69].…”

Section: Kinetic Analysis By Multiple Linear Regression (<10% Cu Extrmentioning

confidence: 99%

Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

Wei

Qian

et al. 2016

Minerals

View full text Add to dashboard Cite

Abstract:To better understand chalcopyrite leach mechanisms and kinetics, for improved Cu extraction during hydrometallurgical processing, chalcopyrite leaching has been conducted at solution redox potential 750 mV, 35-75˝C, and pH 1.0 with and without aqueous iron addition, and pH 1.5 and 2.0 without aqueous iron addition. The activation energy (E a ) values derived indicate chalcopyrite dissolution is initially surface chemical reaction controlled, which is associated with the activities of Fe 3+ and H + with reaction orders of 0.12 and´0.28, respectively. A surface diffusion controlled mechanism is proposed for the later leaching stage with correspondingly low E a values. Surface analyses indicate surface products (predominantly S n 2´a nd S 0 ) did not inhibit chalcopyrite dissolution, consistent with the increased surface area normalised leach rate during the later stage. The addition of aqueous iron plays an important role in accelerating Cu leaching rates, especially at lower temperature, primarily by reducing the length of time of the initial surface chemical reaction controlled stage.

show abstract

Section: Kinetic Analysis By Multiple Linear Regression (<10% Cu Extrmentioning

confidence: 99%

Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

Wei

Qian

et al. 2016

Minerals

View full text Add to dashboard Cite

show abstract

“…In dilute chloride solutions at ambient temperatures, results were obtained that have shown that the rate of leaching of chalcopyrite under these conditions is enhanced if the solution potential is controlled within a potential window (550-620 mV) (Velásquez-Yévenes et al, 2009, 2010aNicol et al, 2010). In the proposed mechanism for enhanced leaching at low potentials, it was suggested that a covellitelike phase is produced as an intermediate and a future publication will present electrochemical evidence for such an intermediate.…”

Section: Introductionmentioning

confidence: 99%

The kinetics of dissolution of synthetic covellite, chalcocite and digenite in dilute chloride solutions at ambient temperatures

2011

Self Cite

View full text Add to dashboard Cite

. (2011) The kinetics of dissolution of synthetic covellite, chalcocite and digenite in dilute chloride solutions at ambient temperatures. Hydrometallurgy, This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTThe kinetics of dissolution of synthetic covellite, chalcocite and digenite in dilute chloride solutions at ambient temperatures. AbstractAn experimental study of the comparative kinetics of dissolution of various synthetic copper sulphides (covellite, chalcocite, digenite) in dilute chloride solutions has been carried out at ambient temperatures such as could be encountered in the heap leaching of secondary copper sulphide minerals.The dissolution of sized synthetic covellite particles was carried out in dilute HCl solutions containing known concentrations of copper(II) and iron(III) at controlled potentials. The results show that the rate of dissolution is similar at potentials of 600 and 650 mV, but is predictably less at a potential of 550 mV. The rate of dissolution is remarkably similar to that of chalcopyrite under similar conditions and is largely independent of Cl -and HCl concentration in the range 0.2 to 2.5 M and 0.1 to 1 M respectively. The effect of temperature is significant and an activation energy of 71.5 kJ mol -1 was derived which confirms a chemical or electrochemical rate-determining reaction on the mineral surface. A mineralogical study of the residue after leachingshows that most of the sulphur is associated with unreacted covellite and occurs as isolated globules on the surface with over 90% of the unreacted covellite surface free of sulphur.Dissolution of synthetic chalcocite and digenite is rapid compared with that of covellite under the same conditions. At a potential of 500 mV, the relatively rapid A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTinitial dissolution of chalcocite and digenite does not proceed beyond about 50% and 45% copper dissolution, respectively, as predicted from the thermodynamics. These results confirm the formation of a covellite-like phase as an intermediate which cannot be leached at a potential of 500 mV. An increase in the potential results in rapid dissolution of this "secondary covellite", relative to primary covellite. These results provide useful information for the conditions that should be used for the heap leaching of ores containing secondary copper sulphide minerals.

show abstract

“…Hence, there is a need to better understand the kinetics and mechanism of chalcopyrite leaching for successful industrial hydrometallurgical leaching implementation [5]. Several alternative mechanisms have been suggested, involving oxidative, reductive/oxidative, non-oxidative and a combination of non-oxidative/oxidative processes [6].…”

Section: Introductionmentioning

confidence: 99%

“…Thus, Equation (5) can be combined with (6) to give the overall reaction. 2Fe 3+ + H 2 S = 2Fe 2+ + S + 2H + (6) This model predicts that the rate of dissolution of chalcopyrite should not increase significantly with the addition of ferric ions higher than 0.1 M because of the formation of Fe 2+ according to Equation (6), which will inhibit the dissolution of chalcopyrite as shown in Equation (5) [6]. However, the deduction that the addition of ferrous ions reduces the dissolution rate is apparently in contradiction to the previously reported results.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Analysis of Possible Chalcopyrite Dissolution Mechanism in Sulfuric Acidic Aqueous Solution

Wang

Chang

et al. 2016

Metals

View full text Add to dashboard Cite

Abstract:The dissolution routes of chalcopyrite in acidic sulfate aqueous solution have been discussed by thermodynamic calculation under different aqueous species concentrations, such as Cu 2+ , Fe 2+ and H 2 S. The results show that for both oxidative dissolution and non-oxidative dissolution of chalcopyrite, the dissolution process undergoes several intermediate steps before completely decomposing to Cu 2+ , Fe 2+ and elemental sulfur, in which bornite and covellite are the most likely intermediates. The dissolution routes of the secondary intermediates have also been discussed and covellite is the most likely final intermediate. Based on these results, some frequently reported phenomena, such as the existence of an optima redox potential range, the promotive action of the addition of Cu 2+ and Fe 2+ , as well as the preferential release of Fe 2+ in the chalcopyrite leaching process, have been explained and elucidated.

show abstract

The dissolution of chalcopyrite in chloride solutions

Cited by 91 publications

References 18 publications

Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

The kinetics of dissolution of synthetic covellite, chalcocite and digenite in dilute chloride solutions at ambient temperatures

Thermodynamic Analysis of Possible Chalcopyrite Dissolution Mechanism in Sulfuric Acidic Aqueous Solution

Contact Info

Product

Resources

About