The oxidation of pyrites as a factor in the spontaneous combustion of coal
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The oxidation of pyrites as a factor in the spontaneous combustion of coal

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Published in [Easton, Pa .
Written in English

Subjects:

  • Coal.,
  • Combustion, Spontaneous.,
  • Oxidation.,
  • Pyrites.

Book details:

Edition Notes

Statementby Sheo-Hen Li ...
ContributionsParr, Samuel Wilson, 1857- joint author.
Classifications
LC ClassificationsTP325 .L5 1925
The Physical Object
Pagination1 p. l., 15 p., 1 l.
Number of Pages15
ID Numbers
Open LibraryOL6702783M
LC Control Number27012922
OCLC/WorldCa30619280

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Coal oxidation at low temperatures (i.e. spontaneous combustion of coal and is . temperature oxidation spontaneous combustion index parameter that is measured on dried coal from a start temperature of 40 C. The relationship of this parameter to thermal runaway performance of as-mined coal has been interpreted on an inferred basis by comparison with coals that have similar R 70 values and coal characteristics. This book explains how to understand, analyze and mitigate spontaneous coal combustion, offers preventive measures to mitigate the hazards of spontaneous coal combustion, and applies experimental techniques to investigate the chemical self-heating properties of : Springer International Publishing. Compared with the first coal spontaneous combustion, the rates of temperature and mass loss change with a heating rate of °C/min were higher at the combustion stage of the second coal.

  1. Introduction. Pyrite (FeS 2) is a naturally occurring material that can be found in concentrated form in nature and also as impurities in coal and many other wide occurrence of pyrite in different minerals and coals makes it one of the main sources of SO 2 emission from various industrial activities, such as the metallurgical industry, power production . In the first part of the study, a programmed heating–oxidation experimental apparatus was used to study coal oxidation and combustion. A thermogravimetric analysis was also performed to quantify the kinetics of coal oxidation, such as the characteristic temperatures, the reaction activation energy, and the frequency factor. The presence of pyrites presents two additional risk factors, the first involving oxidation. Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally experienced spontaneous combustion in the mined-out areas of the mine. This process can result from the disruption caused by mining from. spontaneous combustion. In spontaneous combustion. It begins with a slow oxidation process (as bacterial fermentation or atmospheric oxidation) under conditions not permitting ready dissipation of heat—e.g., in the centre of a haystack or a pile of oily rags. Oxidation gradually raises the temperature inside the mass to the point at which a.

Pearson19 showed that, in the pyrite oxidation process, a minimum of 7 electron-transfer steps are necessary to describe completely the oxidation on the pyrite surface. Furthermore, it is well-known that different bacteria can catalyze the pyrite oxidation at a much rapid rate, making its mechanism even more complex unstable and susceptible to oxidation. Pyrite Marcasite. Pyrite oxidation is also known as pyrite ‘disease’, pyrite ‘rot’, and pyrite ‘decay’, and it is caused and accelerated by the presence of oxygen and water. In this condition pyrite undergoes rapid oxidation; 4FeS. 2 + 13O. 2 + 2H. 2. O Æ4FeSO. 4 + 2H. 2. SO. 4 + 2SO. 2. Both values agree with those reported by Clark ('"), and for coal pyrites and "pure" pyrites respectively. Gross differences in surface areas were also cited by Clark, and by Braley^8), who reported surface areas of and M^/gram for sulfur ball pyrites and "museum-grade" pyrites respectively. 2. Char combustion 3. Pulverized coal char oxidation 4. Gasification and oxy-combustion F Soot oxidation (C. R. Shaddix) Problems APPENDIXES APPENDIX A. THERMOCHEMICAL DATA AND CONVERSION FACTORS Table A1. Conversion factors and physical constants Table A2.