A review of the structure, and fundamental mechanisms and kinetics of the leaching of chalcopyrite

Li, Y.; Kawashima, Nobuyuki; Li, J.; Chandra, Anand P.; Gerson, Andrea R.

doi:10.1016/j.cis.2013.03.004

Cited by 212 publications

(236 citation statements)

References 227 publications

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“…However, the contrasting increase in leachate Cu concentrations with successive cycles suggests that other mechanisms, apart from dissolution, predominate during the oxic phases. In fact, significant Cu leaching might be due to the oxidation of chalcopyrite under oxic conditions as reviewed by Li et al 39 The absence of mine tailings in noncontaminated soils would explain why this increasing trend was not observed in NCN.…”

Section: Column Experimentsmentioning

confidence: 98%

Leaching potential of metallic elements from contaminated soils under anoxia

Balint

Nechifor

Ajmone-Marsan

2014

Environ. Sci.: Processes Impacts

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Environmental ImpactThe higher frequency and intensity of extreme rainfall events, as well as the variations in precipitation patterns and intensities as a result of climate change may cause important shifts in soil hydrological regime. This could expose contaminated soils to significant variations in redox potentials possibly influencing metallic element behaviour and their potential transfer to other environmental compartments. This study shows that alternating soil redox conditions may enhance the release and redistribution of metals in more labile fractions. In particular, the presence of redox-sensitive minerals, such as chalcopyrite, in soils affected by mine tailings, could release significant amounts of Cu due to the alternating redox conditions and therefore have important environmental implications. Graphical abstractThe alternation of redox cycles may play a higher role in the release, leaching and redistribution of metallic elements from contaminated soils with respect to oxidizing and reducing conditions alone. AbstractUnderstanding metallic element (ME) behaviour in soils subjected to alternating redox conditions is of significant environmental importance, particularly for contaminated soils. Although variations in the hydrological status of soils may lead to the release of ME, redox-driven changes in ME dynamics are still not sufficiently understood. We studied the effects of alternating redox cycles 2 on the release, leaching and redistribution of Zn, Cu and Pb in metal mine-contaminated and noncontaminated soils by means of a column experiment. Although the release of Zn was promoted by the onset of reductive conditions, successive redox cycles favoured metal partitioning in less labile fractions limiting its further mobilization. The release of Cu in soil porewaters and redistribution in the solid phase towards more labile pools were strongly dependent on the alternation between oxidizing and reducing conditions. In contaminated soils, the presence of chalcopyrite could have determined the release of Cu under oxic conditions and its relative immobilization under subsequent anoxic conditions. The behaviour of Pb did not seem to be influence by redox status, although higher concentrations in the column leachates with respect to soil porewaters suggested that alternating redox conditions could nonetheless result in substantial mobilization. This study provides evidence that the alternation of soil redox conditions may play a more important role in determining the release and leaching of metallic elements from soils with respect to reducing or oxidizing conditions considered separately.

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Section: Column Experimentsmentioning

confidence: 98%

Leaching potential of metallic elements from contaminated soils under anoxia

Balint

Nechifor

Ajmone-Marsan

2014

Environ. Sci.: Processes Impacts

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“…The slow dissolution rate has been proposed to be due to a slow cathodic half-cell reaction on the chalcopyrite surface [11,16]. In the presence of pyrite, the cathodic half-cell reaction occurs on the pyrite surface as the rest potential of pyrite is greater (660 mV SHE) than that of chalcopyrite (560 mV SHE), forming a galvanic cell with electron transfer from the lower rest potential material (anode) to the material with the greater rest potential (cathode) material [3]. It has been reported that when chalcopyrite is in intimate contact with pyrite, the dissolution rate of chalcopyrite is increased significantly as compared chalcopyrite in isolation [11,14,17,18].…”

Section: Introductionmentioning

confidence: 99%

“…Although copper is predominantly extracted using pyrometallurgical processing, much attention has recently been paid to the development of an effective hydrometallurgical extraction methodology [2][3][4][5][6][7][8] due to the potential for improved economics and reduced environmental impact, especially for ore of low copper grade.…”

Section: Introductionmentioning

confidence: 99%

Chalcopyrite Dissolution at 650 mV and 750 mV in the Presence of Pyrite

Qian

et al. 2015

Metals

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Abstract:The dissolution of chalcopyrite in association with pyrite in mine waste results in the severe environmental issue of acid and metalliferous drainage (AMD). To better understand chalcopyrite dissolution, and the impact of chalcopyrite's galvanic interaction with pyrite, chalcopyrite dissolution has been examined at 75 °C, pH 1.0, in the presence of quartz (as an inert mineral) and pyrite. The presence of pyrite increased the chalcopyrite dissolution rate by more than five times at Eh of 650 mV (SHE) (Cu recovery 2.5 cf. 12% over 132 days) due to galvanic interaction between chalcopyrite and pyrite. Dissolution of Cu and Fe was stoichiometric and no pyrite dissolved. Although the chalcopyrite dissolution rate at 750 mV (SHE) was approximately four-fold greater (Cu recovery of 45% within 132 days) as compared to at 650 mV in the presence of pyrite, the galvanic interaction between chalcopyrite and pyrite was negligible. Approximately all of the sulfur from the leached chalcopyrite was converted to S 0 at 750 mV, regardless of the presence of pyrite.At this Eh approximately 60% of the sulfur associated with pyrite dissolution was oxidised to S 0 and the remaining 40% was released in soluble forms, e.g., SO42− . OPEN ACCESSMetals 2015, 5 1567

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“…Additionally, a particle-distribution analysis was performed by means of an optical analysis (Nikon EPIPHOT 200); thus, the sizes of the chalcopyrite particles were found to be in the range of 1-60 μm and 80 % of the particles were below 45 μm. During the leaching operations, sulphuric acid with a purity of 96 % and a density of 1.84 g/cm 3 , obtained from the MERCK Company, and distilled water were used. The pre-heating and drying of the samples was done using a furnace (Protherm PL442T) and a stove (drying oven, MAS DT104), respectively.…”

Section: Materials Analysis and Characterization Of Samplesmentioning

confidence: 99%

“…Chalcopyrite (CuFeS 2 ) is one of the most abundant and widely spread copper-bearing minerals, 3 accounting for approximately 70 % of the Earth's copper. 4 In traditional smelting processes, the chalcopyrite concentrate of a desired grade is obtained with a multistage flotation of a sulphide ore, having fine grains of chalcopyrite dispersed in a matrix of various sulphide minerals and quartz.…”

Section: Introductionmentioning

confidence: 99%

Improvement of selective copper extraction from a heat-treated chalcopyrite concentrate with atmospheric sulphuric-acid leaching

Uzun¹,

Mustafa²,

Atilgan³

2016

Mater. Tehnol.

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The present work focuses on the extraction of Cu, suitable for production, directly from a leach solution of a chalcopyrite concentrate as an alternative to the conventional smelting and refining method. Firstly, the main aspects of the kinetics of chalcopyrite leaching in a sulphuric-acid solution and transformation reactions of chalcopyrite at high temperatures were briefly reviewed. Secondly, atmospheric-acid leaching experiments were performed as a function of the acid content and temperature under agitation. Direct leaching experiments resulted in very low and scattered Cu recoveries, hence revealing a sulphide passivation layer on the chalcopyrite. In order to get rid of this layer, the sulphides in the chalcopyrite were transformed into sulphates with heat treatment at 500°C prior to the leaching process, in which a high dissolution of species was obtained. Finally, the leaching of the pre-heated concentrate resulted in a 99.82 % Cu extraction. Consequently, optimized process parameters were proposed by comparing the Cu extraction and the increased purity of the pregnant solution without Fe impurities. Keywords: chalcopyrite concentrate, leaching, heat treatment, passivation layer, copper extraction, selectivity Namen tega dela je ekstrakcija bakra (Cu), ki bi bila primerna za neposredno proizvodnjo iz lu`ine koncentrata halkopirita, kot alternative obi~ajni metodi s taljenjem in rafinacijo. Najprej je bil opravljen pregled glavnih vidikov kinetike izlu`evanja halkopirita v raztopini solne kisline in reakcij pretvorbe halkopirita pri visokih temperaturah. Nato so bili izvedeni preizkusi izlu`evanja na zraku v kislini, v odvisnosti od vsebnosti kisline in temperature z me{anjem. Neposredni preizkusi izlu`evanja so pokazali zelo nizko in raztreseno pridobitev bakra, ker se je halkopirit prekril s sulfidnim pasivacijskim slojem. Da bi se tega sloja znebili, so bili sulfidi v halkopiritu pretvorjeni v sulfate, s toplotno obdelavo pri 500°C pred postopkom izlu`evanja, pri katerem je bilo dose`eno dobro raztapljanje vzorca. Kon~no je bilo dose`eno 99,82 % izlu`evanje bakra (Cu) iz predogretega koncentrata. Posledi~no so bili predlagani optimalni parametri procesa s primerjavo ekstrakcije bakra (Cu) in pove~ane~istosti nosilne raztopine brez ne~isto~`eleza (Fe).

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A review of the structure, and fundamental mechanisms and kinetics of the leaching of chalcopyrite

Cited by 212 publications

References 227 publications

Leaching potential of metallic elements from contaminated soils under anoxia

Leaching potential of metallic elements from contaminated soils under anoxia

Chalcopyrite Dissolution at 650 mV and 750 mV in the Presence of Pyrite

Improvement of selective copper extraction from a heat-treated chalcopyrite concentrate with atmospheric sulphuric-acid leaching

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