Deep abiotic weathering of pyrite

2020-10-23 · In acid mine drainage, the rate-limiting step is oxidation of aqueous Fe(II) to Fe(III) because Fe(III) is a more efficient oxidant than O 2 in acidic conditions (21, 22, 24). In addition, under acidic or circumneutral pH, OWP can be accelerated by more than one order of magnitude by some iron- and sulfur-oxidizing microorganisms living on or ...

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An overview of acid mine drainage in southwestern Indiana

Pyrite, or iron sulfide (FeS 2 ), is a mineral that is commonly found within Indiana coal seams and the adjacent rock strata. When coal beds and surrounding rock units are disturbed during mining, the associated pyrite is exposed to oxygen and water, and chemical reactions produce highly mineralized acidic mine drainage (AMD).

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Acid Mine Drainage Solutions for the Mineral Industry

2022-7-29 · There are four chemical reactions that represent the chemistry of pyrite weathering to form acid mine drainage. An overall summary reaction is as follows: 2 FeS 2 +7 O 2 +2 H 2 O → 2 FeSO 4 -+2 H 2 SO 4. Pyrite + Oxygen + Water → Ferrous Sulfate + Sulfuric Acid. The acid mine drainage waste is characterized by red water.

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(PDF) Modelling of acid mine drainage physical processes …

Modelling of acid mine drainage physical processes in a waste rock pile with layered co-mingling ... 0 1 S 1 S H 0 D Da the pyrite oxidation reaction kinetics. Three components are thus considered in TOUGH AMD: where x a and x w are given by : water and air, subdivided into two components (oxygen and (ε (1 − S ))2 x + (1 − ε (1 − S )) a ...

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Pyrite oxidation inhibition by organosilane coatings for …

2015-3-1 · DOI: 10.1016/J.MINENG.2014.12.020 Corpus ID: 98523106; Pyrite oxidation inhibition by organosilane coatings for acid mine drainage control @article{Ouyang2015PyriteOI, title={Pyrite oxidation inhibition by organosilane coatings for acid mine drainage control}, author={Yuting Ouyang and Yun Liu and Runliang Zhu and Fei Ge and Tianyuan Xu and Zan …

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Reduction of acid mine drainage by passivation of pyrite …

Acid mine drainage (AMD), a source of considerable environmental pollution worldwide, has prompted the development of many strategies to alleviate its effects. Unfortunately, the methods available for remedial treatment of AMD and the damage it cause are generally costly, labor-intensive, and time-consuming.

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Pyrite Oxidation in Acid Mine Drainage Systems: A …

2021-4-21 · Pyrite oxidation reaction progress according to experimental condition 40 Figure 4. ... Abandoned mines and acid mine drainage affect the ancestral homelands and water resources of many tribes in the western United States, including the Diné (Navajo) in Utah, Arizona, and New Mexico; the bands of the ...

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Investigation of pyrite oxidation and acid mine drainage ...

2010-2-3 · Acid mine drainage (AMD) pollution is considered to be the most serious water pollution problem in mining areas. AMD containing iron sulfates and other components can affect the receiving water bodies. Pyrite oxidation and AMD generation can be considered as important processes that may take place in the wastes produced by coal mining and coal washing …

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Iron oxyhydroxide coating of pyrite for acid mine drainage …

2009-9-1 · Because of its abundance, pyrite is commonly the main source of acid production in mine wastes. The pH of freshly exposed pyrite bearing rocks is usually greater than four so that dissolved O 2 (DO) is the principal pyrite oxidant and the rate of acid production is relatively low (Fig. 1, py–DO reaction in Table 1) (Williamson and Rimstidt, 1994). ...

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A review: Pyrite oxidation mechanisms and acid mine …

2009-1-9 · This acid drainage, commonly referred to as acid mine drainage (AMD), has become an economic and environmental burden. This review deals with abiotic/biotic modes of pyrite oxidation and the mechanistic involvement of OH ‐, O 2, and Fe 3+ in the pyrite oxidation process in low/high pH environments.

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(PDF) Acid Mine Drainage From Reclaimed Coal Strip …

1984-2-1 · A model describing the long-term oxidation of pyrite and the removal of reaction products from reclaimed coal strip mines is presented. Both …

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Acid Mine Drainage

2016-1-14 · TRANSCRIPT. TermsAcid Mine Drainage (AMD)Water that is polluted from contact with mining activityAcid Rock Drainage (ARD)Natural rock drainage that is acidic. Acid Mine DrainageWater - from rain and snowmelt+Oxygen - from the air+Pyrite - from the mineReaction =Sulfuric Acid. AMD Chemistry4FeS2 + 14 H2O + 15 O2 4Fe (OH)3 + 8 SO42- + 16 H+Iron ...

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What Is Acid Mine Drainage? Definition, Causes, and …

2022-5-31 · One of the more famous accidents related to acid mine drainage occurred at the Los Frailes mine in Aznalcóllar, Spain, in 1998, when a broken dam …

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(PDF) IRON DYNAMICS IN ACID MINE …

2006-6-30 · The reaction of pyrite with dissolved oxygen has only a very modest . dependence on pH, as is evident from the reaction order in the rat e law. ... (acid mine drainage (AMD)) (Blowes et al. 2005). ...

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Acid Mine Drainage AMD Management

2019-7-19 · Acid mine drainage (AMD), also is a natural occurrence resulting from the exposure of sulfur and iron bearing materials to erosion and weather. Percola- ... The first reaction in the weathering of pyrite includes the oxidation of pyrite by oxygen. Sulfur is oxidized to sulfate and ferrous iron is released. This reac-

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Pyrite Chemistry: The Key for Abatement of Acid Mine …

Pyrite oxidation produces extremely acidic drainages (as low as pH 2) enriched with Fe, Mn, Al, SO 4, and often heavy metals such as Pb, Hg, Cd, etc. (Table 10.1). Pyrite oxidation takes place when the mineral is exposed to air and water. The process is complex because it involves chemical, biological, and electrochemical reactions, and varies ...

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Acid Mine Drainage: Flow-Through Experiments …

2020-6-10 · Pyrite is an iron sulfide mineral which forms with coal deposits and readily weathers in the presence of water and air (Madigan et al., 2000). At many mine sites the presence of pyrite causes a major environmental problem known as acid mine drainage. Bacteria contribute to the problem by utilizing an electron from ferrous iron retrieved

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Prediction of acid mine drainage potential of dump sites …

2020-11-13 · As shown in reaction 1, pyrite combines with molecular oxygen and water, decomposes and releases sulphur dioxide, forming sulphate and passes Fe(II) and H into the environment.The released Fe(II) is oxidized and produces Fe(III) ions. The resulting Fe(III) ion is a powerful oxidizing reagent and, as shown in reaction 2, oxidizes the pyrite rapidly, causing …

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[PDF] A review: Pyrite oxidation mechanisms and acid …

1995-5-2 · A review: Pyrite oxidation mechanisms and acid mine drainage prevention. Abstract Sulfide oxidation, part of sulfur''s biotic/abiotic cycle, is an important natural phenomenon. However, because of the sulfide''s association with metallic ores and fossil fuels in the form of pyrite (FeS2) and the world''s increasing demand for metals and fossil ...

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(PDF) Acid Mine Drainage (AMD): an …

2019-7-15 · The oxidation of iron sulfides in mine wastes is the main cause of acidic, sulfate, and trace element-rich acid mine drainage (AMD). However, the suite of reactions that transform iron from one ...

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Inhibition of pyrite oxidation using PropS-SH/sepiolite …

2020-10-27 · Pyrite, as one of the most abundant sulfide minerals, can be easily oxidized to generate acid mine drainage (AMD). In the present study, a new composite passivator named PropS-SH/sepiolite (PSPT) using γ-mercaptopropyltrimethoxysilane (PropS-SH) as the main passivator and natural sepiolite particles as filler was fabricated and used to suppress the …

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Mining 101.1: Acid Mine Drainage

2018-3-14 · The most common weathering reaction in AMD is that of pyrite show in equation 1. The weathering of chalcopyrite, sphalerite and other sulphide ores (table 1) is similar, ... Acid Mine Drainage From Mines on the National Forests, A Management Challenge. …

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A review: pyrite oxidation mechanisms and acid mine …

1995-11-1 · @misc{etde_123093, title = {A review: pyrite oxidation mechanisms and acid mine drainage prevention} author = {Evangelou, V P, and Zhang, Y L} abstractNote = {Sulfide oxidation, part of sulfur`s biotic/abiotic cycle, is an important natural phenomenon. However, because of the sulfide`s association with metallic ores and fossil fuels in the form of pyrite …

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Acid Mine Drainage

2022-7-28 · Environmental Notes on Mining, updated September 2009 Pyrite (FeS2) is commonly associated with coal and metal ore deposits. Its oxidation occurs spontaneously in nature, causing environmental problems like Acid Mine Drainage (AMD) and mine-tailing leachate containing heavy metals. Discharge of acid drainage into water bodies causes an instant ...

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Acid Mine Drainage

Acid mine drainage (AMD), which can have pH values as low as –3.6 (Nordstrom et al., ... These simulations indicate that the number of moles of calcite needed to neutralize the water should be twice that for pyrite assuming reactions reach equilibrium (i.e., no armoring effects of iron precipitates on the calcite to change its dissolution ...

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(PDF) Acid Mine Drainage From Reclaimed Coal …

1984-2-1 · A model describing the long-term oxidation of pyrite and the removal of reaction products from reclaimed coal strip mines is presented. Both direct-oxygen and ferric iron oxidation of pyrite are ...

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How does mine drainage occur? | U.S.

Mine drainage is formed when pyrite (an iron sulfide) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of …

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How Acid Mine Drainage Has Affected the Greater …

2019-11-15 · There are three main reactions that occur in acid mine drainage. For the sake of this lesson, the equations below that illustrate these reactions are simplified non-quantitative: The first reaction that occurs in acid mine drainage is: +2 FeS 2 + O 2 + H 2 O –> Fe + H 2 SO 4 or (pyrite + dissolved oxygen + water) -> (ferrous iron+ sulfuric acid)

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Acid mine drainage

As pyrite oxidation proceeds and the pH of the surrounding environment gradually decreases to 4.5, the solubility of ferric hydroxide increase, and Fe 3+ gradually replaces O 2 as the primary oxidant (Pierre Louis et al., 2015) cause the oxidation rate of pyrite by reaction with Fe 3+ is at least two orders of magnitude faster than that by reaction with O 2 (Moses et al., 1987), pyrite ...

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Reduction of acid mine drainage by passivation of pyrite …

2022-4-1 · Pyrite is a common gangue mineral in mine wastes, and its oxidation is the primary cause of acid mine drainage (AMD) formation, which is a very serious environmental problem encountered worldwide.

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3.1 An introduction to acid mine drainage

2015-3-30 · An introduction to acid mine drainage . Iron pyrite, FeS2, also known as ''fool''s gold'', is the most important source of nearly all water pollution originating from mines and their residue deposits. ... This oxidation reaction is accelerated and extended by bacteria. The most important of these bacteria is Thiobacillus ferrooxidans.

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