Improved Chalcopyrite Leaching Through Optimization of Redox Potential

Hiroyoshi, Naoki; Tsunekawa, Masami; Okamoto, Hideyuki; Nakayama, Ryoichi; Kuroiwa, Shigeto

doi:10.1179/cmq.2008.47.3.253

Cited by 31 publications

(21 citation statements)

References 9 publications

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“…It should be noted that, in a proposed model for chalcopyrite dissolution, chalcocite and bornite were formed initially and then gradually transformed to covellite [33][34][35]. In the present study, we also found that the chalcocite and bornite species formed at the early stage ( Figure 8) and then transformed to covellite for both mesophilic and thermophilic cultures in the absence of Ag + .…”

Section: Discussionsupporting

confidence: 74%

“…The mineralogical composition tests (by SR-XRD) indicate that the original chalcopyrite is pure mineral (Figure 1). X-ray fluorescence spectroscopic analysis shows that the original chalcopyrite comprised of (mass fraction, wt %): Cu, 33 0.5 g/L; K2HPO4, 0.5 g/L; KCl, 0.1 g/L; Ca(NO3)2, 0.01 g/L. Additionally, 0.2 g/L of yeast extracts were added to the thermophilic culture.…”

Section: Mineral Samplesmentioning

confidence: 99%

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Synchrotron Radiation Based Study of the Catalytic Mechanism of Ag+ to Chalcopyrite Bioleaching by Mesophilic and Thermophilic Cultures

et al. 2018

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The catalytic mechanism of Ag+ for chalcopyrite bioleaching by mesophilic culture (at 30 °C) and thermophilic culture (at 48 °C) was investigated using synchrotron radiation-based X-ray diffraction (SR-XRD) and S K-edge and Fe L-edge X-ray absorption near edge structure (XANES) spectroscopy. Bioleaching experiments showed that copper extraction from chalcopyrite bioleaching by both cultures was promoted significantly by Ag+, with more serious corrosion occurring on the minerals surface. SR-XRD and XANES analyses showed that the intermediates S0, jarosite and secondary minerals (bornite, chalcocite and covellite) formed for all bioleaching experiments. For these secondary minerals, the formation of bornite and covellite was promoted significantly in the presence of Ag+ for both cultures, while Ag+ has almost no effect on the formation of chalcocite. These results provided insight into the catalytic mechanisms of Ag+ to chalcopyrite bioleaching by the mesophilic and thermophilic cultures, which are both probably due to the rapid formation of bornite by Ag+ and the conversion of bornite to covellite.

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Section: Discussionsupporting

confidence: 74%

Section: Mineral Samplesmentioning

confidence: 99%

Synchrotron Radiation Based Study of the Catalytic Mechanism of Ag+ to Chalcopyrite Bioleaching by Mesophilic and Thermophilic Cultures

et al. 2018

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“…It is known hydrolysis and precipitation of Fe 3+ can be minimized when pH is b 2 (Dreisinger and Abed, 2002;Li et al, 2013), and sulfur oxidizing activity as well as consortium of bioleaching microbes are dependent on temperature and pH (Zhu et al, 2013). Hiroyoshi et al (2002Hiroyoshi et al ( , 2008 proposed a two-step dissolution model based on the oxidation-reduction potential (ORP) in the solution. As shown by Eqs.…”

Section: Introductionmentioning

confidence: 99%

Relatedness of Cu and Fe speciation to chalcopyrite bioleaching by Acidithiobacillus ferrooxidans

2015

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“…A study by Jeevaratnam et al (2005) suggested an optimum range of solution redox potential with a maximum Cu leach rate in sulphuric acid at 70°C and pH 1.5 achieved at 800 mV SHE with the rate decreasing with increased solution redox potential thereafter. A mechanism proposed by Hiroyoshi et al (2008) suggests that the first and rate limiting step, in a two-step leach mechanism, is the reduction of chalcopyrite to chalcocite (Cu 2 S) which is favoured by low solution redox potential, and requires the presence of Fe 2+ :…”

Section: Introductionmentioning

confidence: 99%