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impurities in iron pyrite 2012011

Impurities and heterogeneity in pyrite: Influences on ...

01/02/2008  1. Introduction. Oxidation of naturally occurring pyrite (FeS 2) contributes to environmental degradation at mine sites and in mineralized regions.In addition to acid production, oxidizing pyrite also serves as a source of potentially toxic trace elements; it almost always contains As, Co and Ni impurities in some combination (Shuey, 1975, Reich et al., 2005), and may contain other impurities ...

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The effect of As, Co, and Ni impurities on pyrite ...

Pyrite samples synthesized with As, Co, or Ni impurities and without added impurities were oxidized in batch and mixed flow-through reactors in the presence of 1 mM ferric iron, at pH 2.

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The effect of Ni impurities on some structural properties ...

Iron disulphide pyrite (Fe) is considered as a good semiconductor useful. for solar ... Effect of Ni impurities on pyrite thinJilms 21 19 established a linear dependence between the change in composition and the decrease of the lattice constant in GaAs, which was demonstrated to be due to the formation of Ga vacancies. Furthermore, Krill et al [ZZ] [email protected] the lattice~parameter as a

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The Effect of Co, Ni, and Cr Impurities on the Properties ...

Iron Pyrite (FeS 2) is a promising photovoltaic material for mul%-TW scale deployment. • Strong light absorp%on (α > 105 for hν > 1.4 eV) • Suitable bandgap (E g ~ 0.95 eV) • Earth abundant, non-toxic Progress has been limited, in part, by lack

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Pyrite - Wikipedia

Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant method. Pyrite remains in

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The effect of As, Co, and Ni impurities on pyrite ...

The anodic dissolution of pyrite and the reduction of ferric iron half-reactions are taken as proxies for natural pyrite oxidation. Pyrite containing no impurities is least reactive. Pyrite with As is more reactive than pyrite with either Ni or Co despite lower dopant concentration. As, Co, and Ni impurities introduce bulk defect states at different energy levels within the band gap. Higher ...

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Magnetic susceptibility of iron pyrite (FeS2) between 4.2 ...

01/04/1977  The interest in iron pyrite is partially due to the fact that it is one of the principal sulfur bearing minerals in coals. 1~. is known that FeS2 is a semiconductor whose properties are strongly affec- ted by impurities in natural crystals [3]. Electrical trans- port properties and optical measurements [4] have shown that the semiconducting band gap in iron pyrite is about I eV. The magnetic ...

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The Effect of Co, Ni, and Cr Impurities on the Properties ...

Iron Pyrite (FeS 2) is a promising photovoltaic material for mul%-TW scale deployment. • Strong light absorp%on (α > 105 for hν > 1.4 eV) • Suitable bandgap (E g ~ 0.95 eV) • Earth abundant, non-toxic Progress has been limited, in part, by lack of understanding and control of doping. We conducted a

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The effect of Ni impurities on some structural properties ...

Iron disulphide pyrite (Fe) is considered as a good semiconductor useful. for solar ... Effect of Ni impurities on pyrite thinJilms 21 19 established a linear dependence between the change in composition and the decrease of the lattice constant in GaAs, which was demonstrated to be due to the formation of Ga vacancies. Furthermore, Krill et al [ZZ] [email protected] the lattice~parameter as a measure of ...

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The effect of As, Co, and Ni impurities on pyrite ...

Pyrite samples synthesized with As, Co, or Ni impurities and without added impurities were oxidized in batch and mixed flow-through reactors in the presence of 1 mM ferric iron, at pH 2.

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Direct Chemical Vapor Deposition Synthesis of Phase-Pure ...

Resurgent interest in iron pyrite (FeS 2) as an earth-abundant, nontoxic semiconductor for solar applications has resulted in many attempts to grow phase-pure thin films via chemical vapor deposition (CVD). However, all thin films grown via CVD or sulfidation to date have contained marcasite phase or other iron sulfide impurities.

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The electrical resistivity of galena, pyrite, and chalcopyrite

In pyrite, electrically active impurities include cobalt, nickel, and copper as donors, and arsenic as an acceptor. Deviations from stoichiometry, in the same sense as galena, may be important. Pyrites from sedimentary and epithermal deposits are usually p-type if cupriferous sulfides are not present.

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A review of the properties of pyrite and the implications ...

A review of the properties of pyrite impurities in bentonite clay has been carried out based on infor­ mation available in the literature. The main focus of the review is the extent to which pyrite dissolu­ tion during the long­term anaerobic period could support corrosion of the canister, most likely as the result of the release of dissolved sulphide or polysulphide species. In addition ...

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Extracting iron - Iron and aluminium - GCSE Chemistry ...

in a huge container called a blast furnace. Iron ores such as haematite contain iron(III) oxide, Fe 2 O 3.The oxygen must be removed from the iron(III) oxide in order to leave the iron behind.

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Impurities in Limestone - Civil Engineers PK

21/10/2016  Iron Compounds Iron occurs in small proportions as oxides, carbonates and sulphides. They are converted into Fe2O3 at lower temperatures of calcination. At higher temperatures iron combines with lime and silicates and forms complex silicate compounds. Pyrite or iron sulphide is regarded to be highly undesirable. For hydraulic limes 2-5 per cent of iron oxide is necessary.

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The effect of Ni impurities on some structural properties ...

Iron disulphide pyrite (Fe) is considered as a good semiconductor useful. for solar ... Effect of Ni impurities on pyrite thinJilms 21 19 established a linear dependence between the change in composition and the decrease of the lattice constant in GaAs, which was demonstrated to be due to the formation of Ga vacancies. Furthermore, Krill et al [ZZ] [email protected] the lattice~parameter as a measure of ...

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Effects from As, Co, and Ni impurities on pyrite oxidation ...

The anodic dissolution of pyrite and the reduction of ferric iron half-reactions were taken as proxies for natural pyrite oxidation. Pyrite containing no impurities is least reactive. Pyrite with As is more reactive than pyrite with either Ni or Co despite lower dopant concentration. Solid state measurements, AC voltammetry, and EIS data agree with previous studies reporting As, Co and Ni ...

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The effect of As, Co, and Ni impurities on pyrite ...

The anodic dissolution of pyrite and the reduction of ferric iron half-reactions are taken as proxies for natural pyrite oxidation. Pyrite containing no impurities is least reactive. Pyrite with As is more reactive than pyrite with either Ni or Co despite lower dopant concentration. As, Co, and Ni impurities introduce bulk defect states at different energy levels within the band gap. Higher ...

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The Effect of Co, Ni, and Cr Impurities on the Electronic ...

Iron pyrite (FeS2) is an earth-abundant, non-toxic material that has a suitable band gap of 0.95 eV, a large optical absorption coefficient, and adequate carrier diffusion lengths for use in photovoltaic applications. However, its practical use is limited in part by poor understanding and control of doping. Here, we employ variable temperature Hall effect and conductivity to study, in detail ...

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A review of the properties of pyrite and the implications ...

A review of the properties of pyrite impurities in bentonite clay has been carried out based on infor­ mation available in the literature. The main focus of the review is the extent to which pyrite dissolu­ tion during the long­term anaerobic period could support corrosion of the canister, most likely as the result of the release of dissolved sulphide or polysulphide species. In addition ...

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Pyrite (#73) Geology Department Displays

Pyrite (FeS 2), is found in all kinds of rocks - igneous, metamorphic, and sedimentary - but usually in small to modest amounts. In ore deposits, it is often found in massive aggregates, as you can see from this specimen. In fact, pyrite is the most common of the sulfide minerals (those with a metal combined with sulfur). So you might wonder how many pyrite mines we have in the U.S. The answer ...

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Pyrite: Mineral information, data and localities.

Pyrite Group. The isometric (cubic) polymorph of orthorhombic marcasite.Compare UM1997-43-S:Fe. Pyrite is a very common mineral (also one of the most common natural sulfides, and the most common disulfide), found in a wide variety of geological formations from sedimentary deposits to hydrothermal veins and as a constituent of metamorphic rocks.The brassy-yellow metallic colour of pyrite has in ...

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Direct Chemical Vapor Deposition Synthesis of Phase-Pure ...

Resurgent interest in iron pyrite (FeS2) as an earth-abundant, nontoxic semiconductor for solar applications has resulted in many attempts to grow phase-pure thin films via chemical vapor deposition (CVD). However, all thin films grown via CVD or sulfidation to date have contained marcasite phase or other iron sulfide impurities. Here, we report the use of metallic cobalt pyrite (cattierite ...

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TACKLING IMPURITIES IN COPPER CONCENTRATES

Pyrite FeS 2 7 33 Tennantite (Cu,Fe,Zn) 12 As 4 S 13 0.2 18 Tetrahedrite (Cu,Fe,Zn) 12 Sb 4 S 13 1 Sphalerite ZnS 6.5 Other Cu S= Cu 2 S, CuS, Cu 5 FeS 4 1.3 Concentrate “A” has the sulphides being mostly chalcopyrite and some pyrite and a higher gangue fraction. Concentrate “B” distributes its copper mostly between chalcopyrite and ...

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Iron pyrite (FeS2) is the form in which much of the sulfur ...

29/07/2012  Iron pyrite (FeS2) is the form in which much of the sulfur exists in coal. In the combustion of coal, oxygen reacts with iron pyrite to produce iron(III) oxide and sulfur dioxide, which is a major source of air pollution and a substantial contributor to acid rain. What mass of Fe2O3 is produced from 63 L of oxygen at 2.67 atm and 154 C with an excess of iron pyrite?

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The effect of As, Co, and Ni impurities on pyrite ...

Pyrite samples synthesized with As, Co, or Ni impurities and without added impurities were oxidized in batch and mixed flow-through reactors in the presence of 1 mM ferric iron, at pH 2. Six samples from each dopant population were used to provide a statistically robust comparison; two natural samples from Leadville, CO (major impurities Pb, As, Bi, Ag, Zn) and Elba, Italy (Co,

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Effects from As, Co, and Ni impurities on pyrite oxidation ...

The anodic dissolution of pyrite and the reduction of ferric iron half-reactions were taken as proxies for natural pyrite oxidation. Pyrite containing no impurities is least reactive. Pyrite with As is more reactive than pyrite with either Ni or Co despite lower dopant concentration. Solid state measurements, AC voltammetry, and EIS data agree with previous studies reporting As,

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acs NL nl-2011-02902z 1..5 - 2011 pyrite synthesis

caused by iron pyrite phase impurities and, more importantly, large density surface states.s The large density surface states originate from thermodynamically unstable particle surfaces that are terminated with sulfur dimers.9 The sulfur dimers tend to segregate to the surface and cause vanishing of the hybridized American Chemical band, at the top of the Fe layer, making the

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Density functional theory study of influence of impurity ...

covalent bond between arsenic and iron atoms in pyrite, and the electronic structure of pyrite becomes metallic gradually with the increase of arsenic concentration. Recently, CHEN et al [10−16] studied the effect of lattice impurities on electronic structures and flotation behaviors of sphalerite and galena. However, few theoretical results concerning the influence of impurities

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impurities in iron pyrite 2010 2011 - Csc Mons-La Louvière

Impurities In Iron Pyrite 2010 2011 - unfallchirurgie-suhl.de. Impurities in iron pyrite 2010 2011 uthaya clays and minerals iron sulfide formation3102011 pyrite and other ironbearing sulfide minerals oxidize in the presence of oxygen and water and can produce acid, as well as iron oxyhydroxides and su. Difference between iron ore and iron golds. Mar 10, 2017 impurities in iron

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Template-directed synthesis of ordered iron pyrite (FeS 2 ...

Highly ordered iron pyrite (FeS2) nanowires and nanotubes arrays have been fabricated by using sol–gel method with AAO templates. The prepared nanowires and nanotubes have uniform lengths and 200 nm diameters. Their crystal phase was identified as cubic FeS2 by using X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy and

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WO2015167647A3 - Iron pyrite nanocrystal film as a copper ...

The invention discloses nanocrystalline (NC) FeS 2 thin films as the back contact for CdTe solar cells. In one example, the FeS 2 NC layer is prepared from a solution directly on the CdTe surface using spin-casting and chemical treatment at ambient temperature and pressure, without a thermal treatment step. Solar cells prepared by applying the NC FeS 2 back contact onto

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RU2562180C1 - Method of recycling pyrite cinders - Google ...

Before mixing, oxidising roasting of pyrite cinders is carried out. Ammonium chloride is taken in excess to 30% from stoichiometric quantity, required for formation of ammonium pentachloroferrate. Chlorination is carried out in two stages: at first stage heating is realised in interval of temperatures 200-310°C, at second - higher than 320°C for sublimation of iron (III)

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REMOVAL OF SULFUR AND PHOSPHOROUS FROM IRON ORE ...

of the iron ore rocks and mines contain sulfide minerals such as pyrite, chalcopyrite, arsenopyrite, etc. The sulfur content of iron ore concentrates is generally about 0.5% to 2%, and sometimes more than 0.7%, while the permitted limit of steel industries is 0.1% (Soltanmohammadi et al., 2011). Meanwhile, the percentage of sulfur increases . 846 H.

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Iron pyrite (FeS2) is the form in which much of the sulfur ...

29/07/2012  Iron pyrite (FeS2) is the form in which much of the sulfur exists in coal. In the combustion of coal, oxygen reacts with iron pyrite to produce iron(III) oxide and sulfur dioxide, which is a major source of air pollution and a substantial contributor to acid rain. What mass of Fe2O3 is produced from 63 L of oxygen at 2.67 atm and 154 C with an excess of iron pyrite?

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