Comparative XPS study between experimentally and naturally weathered pyrites

Cai, Yuanfeng; Pan, Yuguan; Xue, Jianpeng; Zhang, Jiayi; Su, Guizhen; Li, Xiang

doi:10.1016/j.apsusc.2009.06.028

Cited by 127 publications

(32 citation statements)

References 88 publications

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“…The peak at 161.3 eV is interpreted as S 2− (Nesbitt et al 1995), and the other two peaks at 161.8 eV and 162.7 eV represent S 2 2− (surface) and S 2 2− (bulk), respectively . According to previous studies, the peaks are S n 2− = 163.8 eV (Corkhill et al 2008), S 0 = 164.4 eV (Cai et al 2009), SO 3 2− = 166.5 eV (Corkhill et al 2008;Nesbitt and Muir 1998), S 2 O 3 2− = 167.7 eV (Descostes et al 2000), and SO 4 2− = 168.4 eV (Corkhill et al 2008;Nesbitt et al 1995). In general, the reported uncertainty of XPS analysis is within 5% (Ray and Shard 2011), and occasionally up to 6.5% (Seah et al 2001).…”

Section: Instrumental Analysismentioning

confidence: 94%

“…Using XPS analysis, occurrence of thiosulfate on microbially leached pyrite surface has been demonstrated, and ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 5 stepwise oxidation of sulfur in pyrite has been proposed (Borda et al 2003a;Demoisson et al 2008;Rimstidt and Vaughan 2003). On the basis of XPS analysis, the elemental preferences in pyrite oxidation have been investigated; the results indicate that abiotic reaction preferentially oxidizes iron rather than sulfur while the preference is reversed in microbial cases (Blight et al 2000;Cai et al 2009;Descostes et al 2000;Nesbitt et al 2000 A. ferrooxidans strain was isolated from an AMD pond in the Shizishan Cu-Au mine, Tongling, eastern China (Tu et al 2013). Before experiments, cells were grown in 9K culture medium (Silverman and Lundgren 1959 Fe 3+ adsorption on bacteria surfaces as much as possible (Wightman and Fein 2005).…”

Section: Acidithiobacillus Ferrooxidans (A Ferrooxidans) Is An Impormentioning

confidence: 98%

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Sulfur Transformation in Microbially Mediated Pyrite Oxidation by Acidithiobacillus ferrooxidans: Insights From X-ray Photoelectron Spectroscopy-Based Quantitative Depth Profiling

et al. 2016

Geomicrobiology Journal

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2015): Sulfur transformation in microbially mediated pyrite oxidation by Acidithiobacillus ferrooxidans: insights from X-ray photoelectron spectroscopy-based quantitative depth profiling, Geomicrobiology Journal, AbstractThe oxidation of pyrite and other sulfides is responsible for the generation of acid mine drainage and acid rock drainage, which leads to further contamination of soil and water. In these processes, microbial oxidation usually prevails over chemical oxidation. To determine the mechanism of microbial oxidation of pyrite, the interaction of Acidithiobacillus ferrooxidans with pyrite was comprehensively studied, and the sulfur transformation in the interaction was disclosed using X-ray photoelectron spectroscopy (XPS) depth profiling. Abundant bacterial cells attach to pyrite Downloaded by [New York University] at 11:43 18 June 2015 ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 2 surface and form biofilms, which greatly enhances surface corrosion and results in two types of etching pits: bacteria-driven rod-shaped and chemically driven hexagonal etching pits. The details of XPS depth profiles on a reacted pyrite surface reveal that the surface sulfur was first oxidized into elemental sulfur. Thereafter, elemental sulfur was further oxidized to intermediate species S 2 O 3 2− and SO 3 2− and ultimately to SO 4 2− . The oxidation sequence of sulfur is S 2 2− /S 2− → S n 2− , S 0 →SO 3 2− , and S 2 O 3 2− →SO 4 2− . Meanwhile, the remnant ferrous iron in the surface layer was released into solution and subsequently oxidized into Fe 3+ by A. ferrooxidans and dissolved oxygen, which in turn enhanced the oxidation of sulfur. Fe 3+ , sulfate, and other ions (e.g., K + , Na + , NH 4 + ) in the solution precipitated as jarosite, hydroniumjarosite, and ammoniojarosite. On the basis of results, a three-staged model is proposed to interpret the kinetics of microbial oxidation of pyrite.

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Section: Instrumental Analysismentioning

confidence: 94%

Section: Acidithiobacillus Ferrooxidans (A Ferrooxidans) Is An Impormentioning

confidence: 98%

Sulfur Transformation in Microbially Mediated Pyrite Oxidation by Acidithiobacillus ferrooxidans: Insights From X-ray Photoelectron Spectroscopy-Based Quantitative Depth Profiling

et al. 2016

Geomicrobiology Journal

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“…The raw Ca 2p spectrum was composed of three fitted curves. The binding energy at 347.1, 347.7 and 348.2 eV was the XPS peaks of Ca 2p3/2 for calcite, apatite and gypsum, respectively (curve (a) in Figure 8) [20][21][22]. After DSAD, the peaks at 133.8, 347.1 and 347.7 eV disappeared.…”

Section: Analysis Of Leaching Residue and Leachatementioning

confidence: 99%

“…With this method, the Equation (2) was determined as theoretical equilibrium reaction of calcite in sulfuric acid solution. Similarly, the theoretical equilibrium reactions of hematite, mica, alunite, apatite and V 2 O 4 in sulfuric acid solution were determined as Equations (4), (5), (7), (18) and (20), respectively.…”

Section: Thermodynamics Analysismentioning

confidence: 99%

Selective Leaching of Vanadium from Roasted Stone Coal by Dilute Sulfuric Acid Dephosphorization-Two-Stage Pressure Acid Leaching

et al. 2016

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A novel staged leaching process has been reported in this paper to selectively extract vanadium from roasted stone coal and the mechanisms have been clarified. Results showed that the leaching efficiency of V, Al, P and Fe was 80.46%, 12.24%, 0.67% and 3.12%, respectively, under the optimum dilute sulfuric acid dephosphorization (DSAD)-two-stage pressure acid leaching (PAL) conditions. The efficient separation of V from Fe, Al and P was realized. As apatite could be leached more easily than mica, the apatite could completely react with sulfuric acid, while the mica had almost no change in the DSAD process, which was the key aspect in realizing the effective separation of V from P. Similarly, the hydrolyzation of Fe and Al could be initiated more easily than that of V by decreasing the residual acid of leachate. The alunite and iron-sulphate compound generated in the first-stage PAL process resulted in the effective separation of V from Fe and Al.

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“…Figure 14 and Table 4 show the fitting results for Fe 2p and Si 2p binding energy spectra. Figure 14a shows the XPS-fitted peak for Fe3O4 [16]. For pre-flocculation, the binding energy of Fe 2p is 711.35 eV.…”

Section: Analysis Of Flocculation Mechanismmentioning

confidence: 99%

Selective Flocculation Enhanced Magnetic Separation of Ultrafine Disseminated Magnetite Ores

Chen

Zhang

et al. 2016

Minerals

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Abstract:Simple magnetic separation for a certain magnetite mine with ultrafine disseminated lean ores has resulted in low performance, as the fine sizes and aggregation of ground mineral particles have caused inefficient recovery of the ultrafine minerals. In this study, we attempt to increase the apparent sizes of target mineral particles, and improve the separation indices, by using a multi-stage grinding-dispersion-selective flocculation-weak magnetic separation process. The results showed that under the conditions of 500 g/t sodium hexametaphospate (SHMP) as dispersant, 750 g/t carboxymethyl starch (CMS) as flocculant, agitating at 400 rpm for 10 min, with slurry pH 11, and final grinding fineness of 93.5% less than 0.03 mm, the obtained concentrate contained 62.82% iron, with recovery of 79.12% after multi-stage magnetic separation. Compared to simple magnetic separation, the concentrate's iron grade increased by 1.26%, and a recovery rate by 5.08%. Fundamental analysis indicated that, in a dispersed state of dispersion, magnetite particles had weaker negative surface charges than quartz, allowing the adsorption of negative CMS ions via hydrogen bonding. Consequently, the aggregate size of the initial concentrate increased from 24.30 to 38.37 µm, accomplishing the goal of selective flocculation, and increasing the indices of separation.

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Comparative XPS study between experimentally and naturally weathered pyrites

Cited by 127 publications

References 88 publications

Sulfur Transformation in Microbially Mediated Pyrite Oxidation by Acidithiobacillus ferrooxidans: Insights From X-ray Photoelectron Spectroscopy-Based Quantitative Depth Profiling

Sulfur Transformation in Microbially Mediated Pyrite Oxidation by Acidithiobacillus ferrooxidans: Insights From X-ray Photoelectron Spectroscopy-Based Quantitative Depth Profiling

Selective Leaching of Vanadium from Roasted Stone Coal by Dilute Sulfuric Acid Dephosphorization-Two-Stage Pressure Acid Leaching

Selective Flocculation Enhanced Magnetic Separation of Ultrafine Disseminated Magnetite Ores

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