Experimental and Theoretical Analysis Accounting for Differences of Pyrite and Chalcopyrite Oxidative Behaviors for Prospective Environmental and Bioleaching Applications

Lara, René H.; Vazquez‐Arenas, Jorge; Ramos-Sánchez, Guadalupe; Galván, Marcelo; Lartundo-Rojas, L.

doi:10.1021/acs.jpcc.5b05149

Cited by 32 publications

(19 citation statements)

References 66 publications

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“…Up to now, researchers have largely focused their attention on outer surface layers, while the underlying extended defective region could seriously affect surface processes in which the charge transport is important. We hypothesize, in particular, that such structures should take part in the inhibited anodic oxidation and oxidative leaching of pyrite, pyrrhotite and other metal sulfides [1][2][3][4][63][64][65][66]. Noteworthy, the above phenomena arise as a result of the sample handling in atmosphere, that is, in the early stages of metal sulfide oxidation.…”

Section: Discussionmentioning

confidence: 99%

Hard X-ray photoelectron and X-ray absorption spectroscopy characterization of oxidized surfaces of iron sulfides

Mikhlin

Tomashevich

Vorobyev

et al. 2016

Applied Surface Science

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a b s t r a c tHard X-ray photoelectron spectroscopy (HAXPES) using an excitation energy range of 2 keV to 6 keV in combination with Fe K-and S K-edge XANES, measured simultaneously in total electron (TEY) and partial fluorescence yield (PFY) modes, have been applied to study near-surface regions of natural polycrystalline pyrite FeS 2 and pyrrhotite Fe 1−x S before and after etching treatments in an acidic ferric chloride solution. It was found that the following near-surface regions are formed owing to the preferential release of iron from oxidized metal sulfide lattices: (i) a thin, no more than 1-4 nm in depth, outer layer containing polysulfide species, (ii) a layer exhibiting less pronounced stoichiometry deviations and low, if any, concentrations of polysulfide, the composition and dimensions of which vary for pyrite and pyrrhotite and depend on the chemical treatment, and (iii) an extended almost stoichiometric underlayer yielding modified TEY XANES spectra, probably, due to a higher content of defects. We suggest that the extended layered structure should heavily affect the near-surface electronic properties, and processes involving the surface and interfacial charge transfer.

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Section: Discussionmentioning

confidence: 99%

Hard X-ray photoelectron and X-ray absorption spectroscopy characterization of oxidized surfaces of iron sulfides

Mikhlin

Tomashevich

Vorobyev

et al. 2016

Applied Surface Science

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“…10). It is currently accepted that the type, structure, and composition of surface sulfur compounds can influence SM reactivity (Cruz et al 2001a(Cruz et al , b, 2005Nava et al 2008;Murphy and Strongin 2009;Meléndez et al 2010;Lara et al 2015b). The presence of this type of surface sulfur compounds is identified in weathered samples by XPS (Fig.…”

Section: Discussionmentioning

confidence: 99%

Arsenopyrite weathering under conditions of simulated calcareous soil

Lara¹,

Velázquez²,

Vazquez‐Arenas³

et al. 2015

Environ Sci Pollut Res

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Mining activities release arsenopyrite into calcareous soils where it undergoes weathering generating toxic compounds. The research evaluates the environmental impacts of these processes under semi-alkaline carbonated conditions. Electrochemical (cyclic voltammetry, chronoamperometry, EIS), spectroscopic (Raman, XPS), and microscopic (SEM, AFM, TEM) techniques are combined along with chemical analyses of leachates collected from simulated arsenopyrite weathering to comprehensively examine the interfacial mechanisms. Early oxidation stages enhance mineral reactivity through the formation of surface sulfur phases (e.g., S n (2-)/S(0)) with semiconductor properties, leading to oscillatory mineral reactivity. Subsequent steps entail the generation of intermediate siderite (FeCO3)-like, followed by the formation of low-compact mass sub-micro ferric oxyhydroxides (α, γ-FeOOH) with adsorbed arsenic (mainly As(III), and lower amounts of As(V)). In addition, weathering reactions can be influenced by accessible arsenic resulting in the formation of a symplesite (Fe3(AsO4)3)-like compound which is dependent on the amount of accessible arsenic in the system. It is proposed that arsenic release occurs via diffusion across secondary α, γ-FeOOH structures during arsenopyrite weathering. We suggest weathering mechanisms of arsenopyrite in calcareous soil and environmental implications based on experimental data.

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“…S2). These current peaks are related to the oxidation and reduction during the dissolution of pyrite [39].…”

Section: Accepted Manuscriptmentioning

confidence: 98%

An electrochemical sensing approach for scouting microbial chemolithotrophic metabolisms

Saavedra

Figueredo

Cortón

et al. 2018

Bioelectrochemistry

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The present study was aimed to test an electrochemical sensing approach for the detection of an active chemolithotrophic metabolism (and therefore the presence of chemolithotrophic microorganisms) by using the corrosion of pyrite by Acidithiobacillus ferrooxidans as a model. Different electrochemical techniques were combined with adhesion studies and scanning electron microscopy (SEM). The experiments were performed in presence or absence of A. ferrooxidans and without or with ferrous iron in the culture medium (0 and 0.5 g L, respectively). Electrochemical parameters were in agreement with voltammetric studies and SEM showing that it is possible to distinguish between an abiotically-induced corrosion process (AIC) and a microbiologically-induced corrosion process (MIC). The results show that our approach not only allows the detection of chemolithotrophic activity of A. ferrooxidans but also can characterize the corrosion process. This may have different kind of applications, from those related to biomining to life searching missions in other planetary bodies.

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Experimental and Theoretical Analysis Accounting for Differences of Pyrite and Chalcopyrite Oxidative Behaviors for Prospective Environmental and Bioleaching Applications

Cited by 32 publications

References 66 publications

Hard X-ray photoelectron and X-ray absorption spectroscopy characterization of oxidized surfaces of iron sulfides

Hard X-ray photoelectron and X-ray absorption spectroscopy characterization of oxidized surfaces of iron sulfides

Arsenopyrite weathering under conditions of simulated calcareous soil

An electrochemical sensing approach for scouting microbial chemolithotrophic metabolisms

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