Source control on the acid mine drainage produced by the …
1. Introduction. Acid mine drainage (AMD), primarily generated through natural oxidation, rainwater leaching, and oxidizing microbial action on metal sulfide minerals (mainly pyrite) in waste rocks and tailings, is the main source of heavy metal pollution in mining areas and their surrounding environments (Ighalo, 2022).A report …
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Significant Guidance Documents | Office of Surface Mining …
Section I.4 of OMB Bulletin 07-02 defines the term "significant guidance document" as a guidance document disseminated to regulated entities or the general public that may reasonably be anticipated to: Raise novel legal or policy issues arising out of legal mandates, the President's priorities, or the principles set forth in Executive Order ...
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Molecules | Free Full-Text | Research on the Effect of Carbon …
To investigate the effect of carbon defects on the hydrophilicity of the whole surface of the coal pyrite, the adsorption of the single H2O molecule at different sites of the coal pyrite surface was studied with the DFT calculation. It was found that, like the ideal pyrite, the single H2O molecule can stably adsorb at the doping-position, the …
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Mine Drainage | U.S. Geological Survey
Mine drainage is surface water or groundwater that drains from an active or abandoned mine. In some cases, pyrite (an iron sulfide mineral) 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 streams containing ...
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Correlation Between the Mineralogical Properties and …
Pyrite is the most widely distributed sulfide mineral on Earth and is the main product of a variety of hydrothermal gold mineralization systems, such as porphyry copper, orogenic gold, iron oxide–copper–gold, epithermal, and carlin-type gold deposits [].The crystal form and other characteristics of pyrite may vary with the type of deposit, and the …
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Selectively Depress Copper-Activated Pyrite in Copper
Pyrite depression in the flotation of copper ores is difficult due to the activation of Cu2+ ions on pyrite surface. In this study, the radical chain reaction involving the redox cycling of Cu(I/II) induced by sodium metabisulphite (MBS) was exploited to selectively depress the flotation of copper-activated pyrite at pH 8.0. Electrochemical …
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Minerals | Free Full-Text | Natural Pyrite as a Catalyst for a …
The efficient treatment of mineral-processing wastewater has attracted soaring interest recently. This study's objective was to degrade xanthate from flotation tailings wastewater using a pyrite-catalyzed Fenton system. A sodium butyl xanthate (SBX) removal rate of more than 96% was achieved via the method under optimal conditions (a …
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Correlation Between the Mineralogical Properties …
Mining, Metallurgy & Exploration. Article. Correlation Between the Mineralogical Properties and Oxidation Rate of Different Minerogenetic Pyrites: a …
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Recycling of pyrite and gypsum mining residues through …
The thermal dissociation of pyrite tailings was investigated using TGA-DTA-QMS under an inert atmosphere up to 1000 °C with a heating rate of 5 °C/min. Fig. 2 (a) exhibits the TGA-DTA-QMS data, it was observed from the TGA curve that the mass is slightly increased by 1 wt.% up to 400 °C and this may be attributed to the partial …
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Surface chemistry of oxidised pyrite during grinding: EDTA extraction
The decrease in surface hydrophobicity of pyrite particles during grinding is mainly due to two factors: (1) oxidation of pyrite surfaces by dissolved oxygen or Fe 3+ ions and (2) precipitation and adsorption of iron hydroxides/oxyhydroxides onto pyrite surfaces derived from grinding media as a result of galvanic interactions. It is generally ...
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Minerals | Free Full-Text | Changing the Pulp Properties and Surface …
The grinding process plays a crucial role in the floatability of mineral. The present study proposes a scheme to assist in the flotation separation of galena and pyrite by optimizing the choice of grinding media. The effects of grinding media (cast iron balls, steel balls containing 18% chromium, and steel balls containing 12% chromium) on the …
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Researchers point to pyrite as possible source of lithium
Pyrite. (Image from Picryl .) A team led by researchers from West ia University studied 15 middle-Devonian sedimentary rock samples from the Appalachian basin in the US and found plenty of ...
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Hydrogeochemical modelling of pyrite oxidation ion …
The simulation results suggest that the variable flow rate in the vertical direction significantly enhances the pyrite oxidation near the ground surface. Peak concentration of Fe2+, Fe3+, and SO42− near the ground surface is found to be approximately 2–3 times higher in the case of variable flow. ... Opencast mining directly …
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Probing the surface of pyrite
The new measurements reveal, among other things, that on pyrite's surface, a property called an energy bandgap — essential for making solar cells or semiconductor devices — has a value less than …
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Application of Silicate-Based Coating on Pyrite and
The prevention of acid generation from sulfidic mine wastes is a problem that challenges the global scientific community for decades. A promising strategy is related to the formation of coating layer around sulfides for inhibiting surface oxidation. In the current research, the conditions favoring the formation of an efficient silicate-based coating …
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Froth Flotation of Chalcopyrite/Pyrite Ore: A Critical Review
Cyanide is used in many mining plants, but its use has been questioned due to safety and environmental issues. This is because the xanthate and cyanide ions compete for the surface of pyrite, as occurs with the hydroxyl ion. The pyrite surface is covered by the Fe(CN) 6 4− ion according to the following reaction (Equation (20)) . In …
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Quantifying pyrite surface oxidation kinetics by contact …
1.. IntroductionThe surface chemistry of pyrite has been studied extensively over the years. The pyrite/aqueous interaction has been the subject of extensive research in view of its importance in extractive metallurgy, e.g. gold leaching from complex sulfide ores [1], sulfide mineral separation [2], [3], coal preparation [4], [5], geochemistry as well …
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Prediction of acid mine drainage: Where we are
The mining and ore processing of sulfide-bearing deposits generates large volumes of waste rock (WR) and tailings, which often contain barren and residual iron sulfides (e.g., pyrite and pyrrhotite). Sulfide oxidation under atmospheric conditions can generate acidic leachates loaded with high concentrations of dissolved metal( oid )s …
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Evaluation of Functionalized Chitosan Polymers for Pyrite
In this work, polyacrylamide functionalized chitosan polymers (CS-PAMs) of different structural properties were synthesized and investigated as selective depressants of pyrite (FeS 2) in the flotation process of galena (PbS) and chalcopyrite (CuFeS 2) from a complex sulfide ore.Response surface methodology (RSM) with a Box-Behnken design …
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Pyrite Oxidation Mechanism by Oxygen in Aqueous …
The mechanism of the initial steps of pyrite (100) surface oxidation was investigated in detail by means of density functional theory/plane-wave calculations. Pyrite oxidation is related to many environmental and …
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Silicic protective surface films for pyrite oxidation
the oxidation of pyrite-bearing tailings and reduce the production of AMD through chemical leaching tests. Fourier transform infrared (FTIR) analyses and scanning electron microscopy with energy-dispersive spectrometry (SEM/EDS) confirmed the presence of silicic protective surface films of calcium silicate on the surface of pyrite-bearing tailings.
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The role of surface attachment of Thiobacillus ferrooxidans …
Growth of Thiobacillus ferrooxidans on pyrite mineral surfaces and in 9K leach media was studied through estimation of bacterial protein in the different phases. Bacterial attachment was found to be governed by particle size of the mineral, period of incubation and by stationary or agitation conditions used during incubation. Increased …
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Mining and Water Quality | U.S. Geological Survey
Mine drainage is surface water or groundwater that drains from an active or abandoned mine. In some cases, pyrite (an iron sulfide mineral) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. ... Underground mining Surface (open pit) mining Placer mining The location and shape of the deposit, strength of the rock ...
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Silicic protective surface films for pyrite oxidation
The tailings produce acid mine drainage (AMD) due to sulfide minerals, especially pyrite oxidation. AMD has caused serious pollution to the surrounding aquatic and terrestrial ecosystems because of its famous low pH value and high metal and sulfate concentration, which is an urgent environmental problem faced by the world's ore mining industry.
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Drainage by Pyrite Surface Passivation
Keywords: acid and metalliferous drainage control; kinetic leach columns; pyrite surface passivation; reactive natural mine waste; reduced acid generation 1. Introduction Acid and metalliferous drainage (AMD) from mine wastes is a global environmental issue and remains a costly economic and social challenge for the …
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Identification of the sources of mine drainage in a
The main mining methods of the Dashu pyrite mine were the cut-and-fill method and the advancing room-and-pillar method. At the early stage of mining, unconsolidated waste rock or slag was mainly used for filling, and there were many mine decline roadways. The main mining targets were dendritic pyrite and some nodular pyrite.
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Microbial Communities in Acid Mine Drainage and Their
The detection of elements C, O, and P seemed to indicate microbes extensively adsorbed on pyrite specimen surface in this study. Morphology of Microbes Adsorbed on Pyrite Surface Observed by SEM. The results of microbes from K2 sample adsorbed on pyrite specimen surface, after 0, 16, 22, and 42 days, are shown in Fig. 3.
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Inhibition of pyrite oxidation by surface coating: a long …
Pyrite and other iron sulfides are readily oxidized by dissolved oxygen in aqueous phase, producing acidity and Fe 2+, which causes significant environmental problems.Applications of surface coating agents (Na 2 SiO 3 and KH 2 PO 4) were conducted at Boeun (Chungbuk, South Korea) outcrop site, and their efficiencies to …
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Impact of acid mine drainage on groundwater
Combining environmental isotope analysis with principal component analysis can be an effective method to discriminate the inflows and sources of contamination in mining-affected watersheds. This paper presents a field-scale study conducted at an acid mine drainage (AMD)-contaminated site adjacent to a pyrite mine in South China. …
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Pyrite oxidation in alkaline solutions: nature of the product …
Pyrite oxidation in Na 2 CO 3 /NaHCO 3 solutions results in particles that are initially covered by a discontinuous oxide coating that grows with reaction time, thus increasing the overall pyrite surface coverage. In this case, a precipitation confined to the solid/liquid interface is favored by the higher ionic strength of the sodium carbonate ...
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