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 operations in the Golestan province ...
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Pyrite is a widespread natural source of arsenic, which can leach into ground-water aquifers when geologic strata containing pyrite are exposed to the air and water, during coal mining for example. Acid mine drainage and groundwater contamination requires close monitoring to ensure that it has been neutralized before being returned to …
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The other problem associated with pyrite in coal is the formation of acid mine drainage or AMD in the tailing dam when pyrite is disposed as tailing from the flotation process. The disposed pyrite comes in contact with oxygen and water and is oxidized to produce sulfuric acid, which can dissolve toxic heavy metals from other minerals [7].
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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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The transformation of pyrite from coal is a complicated process and may proceed by different types of mechanisms under different conditions. Also, TG is used …
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However, pyrite waste is potentially reusable. Therefore, this study aimed to evaluate possible ways of waste and effluent valorization that are generated during the processing of coal mining pyrite (R1). Raw R1 were subjected to two consecutive leaching processes in distilled water (20 g/L, 70 °C) under mechanical stirring for 40 min.
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Spodumene is a rich source of lithium, which can be refined for use in batteries (Credit: Getty Images) Their combined output allowed Australia to supply roughly half the world's lithium in 2021 ...
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The Department of Energy's Coal-Pyrite Flotation Process has been under development for many years. As of this writing, only pilot plant scale operations have been built and tested. In an attempt to determine the costs associated with full-scale commercial operation of the process, three existing contemporary coal preparation plants with ...
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Coal is the most abundant fossil fuel on earth, providing more than a third of global electricity generation and having a major influence on the world economy [1]. The coal mined in Brazil has a high sulfur content in its composition, requiring the processing of raw coal from mines (Run of Mine – ROM) to meet the specifications
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The pyrite oxidation process has been extensively studied and has been reviewed by Nordstrom (1979). For purposes of this description, the term "pyrite" is used to collectively refer to all ... In some coal measures, the paleoenvironment varies laterally and vertically within a single minesite and is a controlling factor in the inherent ...
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The pyrite ore has a relatively high hardness and a sulfur content of 15-20%. Through the processing of the pyrite production line, the pyrite concentrate contains 42.2% sulfur and is recycled The rate is …
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1. Introduction. Pyrite, a mineral with a chemical formula of FeS 2, is an iron disulfide, which is usually associated with other sulfides and oxides.It is abundant in the …
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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 released 4-5 million cubic meters of pyrite ...
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The risk of AMD leaching was decreased from the source by removing pyrite from fine-grained coal gangue during the bubble flotation process [37][38] [39]. Meanwhile, the low-sulfur clean coal was ...
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The process of pyrite treatment was investigated at temperature range of 200 1000 0C. The samples were in the form of powder and granules. Their weight was in the …
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The process of pyrite and marcasite decomposition as it occurs in coal mining regions is described as an electrochemical process analogous to the corrosion of …
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Suppression of floatability of pyrite in coal processing by carrier microencapsulation
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To explore the occurrence and distribution characteristics of fine-grained pyrites in coal and the effect of pyrite particle size on flotation efficiency, coal samples from Guizhou province and Shanxi province, China, were selected for pyrite morphology observation and sulfur content test before and after flotation desulfurization experiments …
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The source of nearly 50 pct of the sulfur content of an average bituminous coal used by an electric utility is pyrite (FeS2); pyrite is a component that is not chemically bound to the coal and, therefore, can be removed by physical separation methods. Removing 50 to 70 pct of the pyrite would accomplish only a 25- to 35-pct reduction in …
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Pyrite and coal particles were treated in different concentrations of Si() 3 2− solution for 1 h at pH 7–9, and the effect of the concentration on the attachment …
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Abstract. An improved process is disclosed for electrostatic separation of pyrite from powdered crude coal comprising vigorously mixing the powdered crude coal with a selected fatty acid glyceride as a conditioning substance and conducting the electrostatic separation at a relative humidity of 2.5--20 percent and a temperature between room temperature …
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Pyrite in fine coal was heated selectively by microwave energy to strengthen its magnetism in this study. Then, the inorganic sulfur in fine coal (−0.5 mm) was removed using a 2 T strong magnetic roller magnetic separator. The migrating regulation of organic sulfur-containing groups and harmful elements was analyzed by employing a microwave …
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The transformation of pyrite from coal is a complicated process and may proceed by different types of mechanisms under different conditions. Also, TG is used widely in thermal behavior analysis of pyrite [ 10, 11, 12 ], but the composition of evolved gas in each step of the loss of mass cannot be observed only by TG.
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As one of the crucial factors contributing to coal spontaneous combustion, the oxidation of pyrite is a complex process involving multiple reactions, particularly in the presence of oxidants (Fe3+ and O2) and bacteria. However, experimental results based on mineral-pyrite are not entirely applicable to coal-pyrite due to their differences in …
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Fool's gold, or pyrite, is made of worthless iron disulfide, but can contain tiny amounts of the real thing. Using an 'atom probe', research has uncovered a new way gold atoms can hide in ...
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The coal pyrites from Shanxi Lu′an (SX), Shandong Taian (SD), and Inner Mongolia Erdos (NM) regions were selected to simulate the strengthening behavior of pyrite in the microwave enhancement process because of their high pyrite content. The pyrite contents of coals from SX, SD, and NM were 75%, 68%, and 70%, respectively. XRD. …
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Some of the presently commercial coal processing techniques are as follows: 3.1 "Modified Run of Mine Coal • a) Large slate and large sulfur balls removed by hand picking. ... Process Cost and Economics of Pyrite-Coal Utilization (Contractor: Bechtel Corporation) Ref. (B) Study of Process Costs and Economics of Pyrite-Coal Utilization ...
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At lower temperatures (about 800K) or lower oxygen concentrations, pyrite will be transformed by a two-step process: the thermal decomposition of the pyrite to form porous pyrrhotite as the first ...
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The coal mining industries generate a considerable volume of pyrite-rich tailings (FeS 2).However, pyrite waste is potentially reusable. Therefore, this study aimed to evaluate possible ways of waste and effluent valorization that are generated during the processing of coal mining pyrite (R1).
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The coal pyrite from SX, SD and NM regions were chosen to simulate the strengthening behavior of pyrite by the process of microwave enhancement of fine coal. …
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A single-stage flotation process was developed in which coal was floated out and pyrite was depressed. Up to 90% of the pyritic sulfur content of bituminous coal could be removed at 75% coal recovery. The process was applied to …
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In addition, coal pyrite had a lower pyrolysis temperature and greater maximum weight loss than those of ore pyrite, indicating that the existence of organic matter in coal pyrite affected its pyrolysis. ... Ito M, Tsunekawa M (2011) Suppression of flotability of pyrite in coal processing by carrier microencapsulation. Fuel Process Technol 92: ...
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The coal pyrite from SX, SD and NM regions were chosen to simulate the strengthening behavior of pyrite by the process of microwave enhancement of fine coal. Fig.5 shows the relationship between the complex permittivity's real part of coal pyrite and microwave frequency from the three different areas. The complex permittivity's real part …
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SO 2 is one of the main constituents for acid rain formation therefore the separation of pyrite from coal before combustion is environmentally important [1,2] .
Dense media separation, cyclones, jigs, and froth flotation are some of the existing techniques for coal processing [3] . اقرأ المزيد
Formation of pyrite in the process of fine coal desulfurization by microwave enhanced magnetic separation Zhenxing Zhang a Key Laboratory of Coal Processing and Efficient …
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In most operating coal-cleaning plants, a significant amount of pyrite is recovered in the froth during flotation of high-sulfur coal. Reducing the pyrite recovery …
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