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Spontaneous combustion of coal has become an important disaster that threatens the safety of coal mines. FeS 2 is the main component of pyrite, which is suspected to be a major contributor to coal spontaneous combustion (CSC). So, it has important significance to FeS 2 on the characteristics of coal oxidation for prevention and …
The presence of pyrite can change the propensity of coal towards spontaneous combustion. The influences of various pyrite contents on the parameters of …
Xue et al. [16] indicated that the effect of minerals in coal on the efficiency of coal desulfurization was similar in inert and micro-oxygen atmospheres. Chen et al. [17] and Gu et al. [18] proved that a reducing atmosphere promotes the decomposition of pyrite and organic sulfur in coal, and increases the sulfur release rate and H 2 S ...
This manuscript covers only parts of the broader topic of Extraction and recovery of Rare-earth elements and critical materials from coal waste using low cost processing methods. Pyrite oxidation is an essential technique for the geochemical circulations of iron and sulfur, and it is equally helpful to industrial mineral beneficiation …
To assess the thermal transformation process of common sulfide minerals in a nitrogen atmosphere, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and thermogravimetric mass spectrometry are employed to define the influence of the pyrrhotite content in pyrite-pyrrhotite mixtures (mixed minerals). The results …
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 ...
Sulfur dioxide emissions from coal-burning power plants can be significantly lowered by removing pyrite from the coal prior to buming. Conventional wet washing methods remove-pyrite down to fine size; however, because of difficulties associated with wet processing of fine-size coal, dry removal methods offer an attractive alternate.
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.
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 …
A simplifi ed diagram showing the chemical process by which pyrite is oxidized … Well-known coal and metalliferous sulfi de deposits that exist around the world and are associated with AMD ...
Formation of pyrite in the process of fine coal desulfurization by microwave enhanced magnetic separation Zhenxing Zhang, Xinyu Wei, Guanghui Yan, Junwei Guo, Pengfei …
Although the contact angle is smaller and the induction time of coal pyrite is longer than those of coal (Qi et al. 2019), coal pyrite has better floatability than ore pyrite due to the doping of C atoms. Efficient depressants are needed to inhibit the floatability of pyrite in the flotation separation of … See more
In this work, an analysis of impurities in the pyrite of southern Santa Catarina (Brazil), including organic matter, sulfates, iron oxides, calcite, clay and sandstone, …
1. Introduction Iron-containing minerals are considered one of the major contributors of deposition, slagging and fouling problems in the pulverized coal combustion process. 1,2 Pyrite, siderite, ankerite and iron-bearing clay minerals, such as Fe 2+-illite, are the most common iron-bearing minerals in coal. 3,4 Generally, the ash produced from coal …
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 …
Pyrite in coal causes serious environmental pollution in the utilization of coal. Flotation is an appropriate method to remove pyrite present in fine coal. Sodium humate (HA-Na) and 3-mercaptopropionic acid (3-MPA) were used as depressants for pyrite removal in the flotation of fine coal, and their depression mechanisms were …
It is very important to study its electrochemical behavior in the flotation process. This review focuses on researches carried out over the past several decades that have studied electrochemical processes associated with pyrite occurring during flotation. The mechanism of processes such as oxidation, activation, depression, and interactions …
1. Introduction. Coal gangue is an undesired but inevitable by-product emitted during coal mining and processing, accounting for approximately 10 %–15 % of the raw coal output [1].In 2020, China's coal gangue output exceeded 400 million tons [2].Currently, the accumulated coal-gangue stockpile in China is 6 billion tons [3].Coal gangue …
Pyrite found in coal always does react when it comes to the contact of air and that forms the poisonous sulfur oxides. The percentage of pyrites is generally high in coal, so the desulfurization is highly needed for protecting environment. ... Coal Process Technology, 5. Google Scholar Patzek, T. W., & Croft, G. D. (2010). A global coal ...
The particle size range of coal produced by pulverizer 4 should conform as nearly as is conveniently possible to the size range producing maximum pyrite availability, or substantial physical release of pyrite crystals from the coal matrix. Size of pyrite particles is known to vary widely between different types of coals so the preferred ...
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.
Coal is known to be weakly diamagnetic, or essentially nonmagnetic, while most of the mineral material included in coal, particularly iron-containing material such as pyrite, is paramagnetic. As a result, mineral impurities in coal require a high magnetic field intensity to attract weak paramagnetic material that can be removed from coal ...
Euhedral crystalline pyrites in coal samples: (a) S3 sample, Nanyangpo coal mine, Shanxi; (b) S6 sample, Tashan coal mine, Shanxi; (c) S6 sample, Tashan …
1.. IntroductionPyrite (FeS 2) is a quite frequently occurred mineral of sulfur.In nature, pyrite existed in the sulfur minerals and coal in the fine dispersed case as well as in free forms. Thermal decomposition of pyrite is very important in terms of the processing of ores of sulfur, drying and processing of pyrite concantres, and also pyrolysis of coals …
The most common technology for treatment of pyrite concentrate is high temperature (up to 1500 0C) roasting. consumption of the blowing oxygen, formation of …
Additionally, if pyrite is not removed from some coal resources, ... is a useful parameter to explore the interaction mechanism between reagents and mineral surfaces during flotation processing. Zeta potential of the pyrite surface with and without PA treatment was measured across a suitable pH range (Fig. 4). The isoelectric point of the ...
Pyrite (FeS 2) is one of the main tailings derived from coal mining. When processed, pyrite has several applications with high value-added, in contrast, if improperly discarded, it causes major environmental impacts, …
Silver processing, preparation of the ore for use in various products. ... In addition, the mineralization usually includes large amounts of pyrite (FeS 2) and arsenopyrite (FeAsS). ... This is processed by slag fuming, a process whereby the residue is melted to form a slag through which powdered coal or coke is blown along with air. The zinc ...
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 probability of the mineral particle to an air bubble was investigated. As shown in Fig. 1, the attachment probability of pyrite to an air bubble decreased drastically with increasing …
It was also found out that pyrite is intensively dissolved at potentials higher than 0.75V versus SCE and that oxidation rate of pyrite is the highest in hydrochloric acid solutions (≥1M HCl).
Coal mining in South Africa is an important economic activity but it generates large volumes of pyrite-bearing wastes in the form of fine coal slurry and discards. These pose a significant acid rock drainage risk. Researchers at the University of Cape Town have developed a multi-stage separation process which separates the coal slurry into different …
The pyrite from coal mining in southern Santa Catarina (Brazil) is rich in other ferrous compounds, sulfates and oxides according to the infrared spectra. The high silicon content, together with elements such as aluminum, calcium, potassium, magnesium, manganese and sodium, suggest that the material has a sandy and clay fraction.
At substantially low concentrations of pyrophosphate, the flotation of coal pyrite was completely depressed over a wide pH range, while the coal flotation remained unaffected. ... The nature of the clay," International Journal of Mineral Processing, Vol. 17, pp. 225–242. Article Google Scholar Arnold, B.J., and Aplan, F.F., 1990, "The ...
