The spontaneous combustion of coal and its by-products in the Witbank and Sasolburg coalfields of South Africa

Pone, J. Dénis N.; Hein, Kim A.A.; Stracher, Glenn B.; Annegarn, Harold J.; Finkleman, Robert B.; Blake, Donald R.; McCormack, John K.; Schroeder, Paul A.

doi:10.1016/j.coal.2007.01.001

Cited by 284 publications

(138 citation statements)

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“…La pila se cubre con una capa húmeda de las cenizas volantes de la misma central térmica ha demostrado ser la medida más eficaz con el menor coeficiente de pérdidas totales del 3%. Pone et al [17] estudió la combustión espontánea de las vetas de carbón en las minas de Witbank y Sasolburg con el fin de determinar si los elementos químicos tóxicos y compuestos están siendo movilizados en el medio ambiente, los minerales de gas de carbón al fuego (CFGM) identificados incluyen compuestos de azufre y sal amoniacal. Mediante difracción de rayos X (XRD) los estudios de los subproductos CFGM confirmaron la presencia de mascagnita ((NH 4 ) 2SO 4 ), illita ((Al, Si) 4O10 [(OH) 2 , H 2 O]) letovicita ((NH 4 ) 3H (SO4) 2), flogopita (KMG), dióxido de titanio (TiO 2 ), barita (BaSO 4 ), sulfato de hierro (FeSO 4 ), yeso (CaSO 4 • 2HO) y silicato.…”

Section: Introductionunclassified

Glycerol effect on the inhibition of spontaneous combustion of subbituminous coal

Acevedo

Valencia²,

Cortés

2016

Bol. Cienc. Tierra

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Factors favoring the phenomenon of spontaneous combustion in coal mainly depend on the intrinsic properties such as coal particle size, moisture content, among others; the medium in which it is located and how it is stored. Consistent with this, the objective of this work is to evaluate the effect of glycerol on the inhibition of self-combustion as water re-adsorption reducer through the addition of glycerol in different amounts (4, 8, 18 and 28% wt). The coal sample was extracted from the Córdoba department, Colombia. Incipient impregnation method was used to perform the addition of glycerol to the desired quantities. Characterizing the coal samples was performed by: TGA-DTG, nitrogen adsorption at -196 °C, C-H-N-O, FTIR, and SEM. The TGA of the coals evaluated in an air atmosphere, show changes in combustion properties of each sample. D i ignition index is reduced as the coal is impregnated with glycerol, obtaining its lowest value for 8wt% of glycerol. The effect of glycerol in inhibiting the spontaneous combustion of coal is exposed in the adsorption equilibrium; the sample with 8wt% glycerol shows the highest reduction of water adsorption in coal validating the proposed technology as inhibitor agent spontaneous combustion phenomenon found in Colombian coal.Keywords: Adsorption; Coal; Isotherm; Water Efecto del glicerol en la inhibición de la combustión espontánea de carbón sub-bituminoso ResumenFactores que favorecen el fenómeno de auto-combustión del carbón depende principalmente de las propiedades intrínsecas, tales como tamaño de partícula, contenido de humedad, entre otros; el medio en el que se encuentra y cómo se almacena. De acuerdo con esto, el objetivo de este trabajo es evaluar el efecto del glicerol en la inhibición de auto-combustión del carbón como reductor de re-adsorción de agua, mediante la adición de glicerol en diferentes cantidades (4, 8, 18 y 28% en peso). El método de impregnación incipiente se utilizó para adicionar el glicerol a las cantidades deseadas. La caracterización de las muestras se realizó mediante: TGA-DTG, adsorción de nitrógeno a -196 ° C, C-H-N-O, FTIR, y SEM. El TGA de los carbone refleja cambios en las propiedades de combustión de cada muestra. El índice de ignición D i presenta su valor más bajo para la muestra con 8% en peso. El efecto del glicerol en la inhibición de la combustión espontánea del carbón está expuesto en el equilibrio de adsorción; la muestra con 8% en peso de glicerol presenta la mayor reducción de la adsorción de agua en el carbón validando la tecnología propuesta como agente inhibidor del fenómeno de auto-combustión en carbones colombianos.

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Section: Introductionunclassified

Glycerol effect on the inhibition of spontaneous combustion of subbituminous coal

Acevedo

Valencia²,

Cortés

2016

Bol. Cienc. Tierra

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“…The self-combustion process of coal and coal-rich materials is responsible for the mobilization of large quantities of pollutants caused by the volatilization of elements present in coal and associated mineral matter. The environmental impacts caused by coal-related fires includes the emission of harmful gases and particulate matter into the atmosphere, mobilization and leaching of hazardous elements into soil and water, and the formation of solid byproducts (coal fire gas minerals) [10,[32][33][34][35]. As a consequence, the pollution of air, soils, sediments, surface and groundwater, and effects on human health and biodiversity occur.…”

Section: Coal-related Fires-a Geoenvironmental Problemmentioning

confidence: 99%

ECOAL Project—Delivering Solutions for Integrated Monitoring of Coal-Related Fires Supported on Optical Fiber Sensing Technology

et al. 2017

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Abstract:The combustion of coal wastes resulting from mining is of particular environmental concern, and the importance of proper management involving real-time assessment of their status and identification of probable evolution scenarios is recognized. Continuous monitoring of the combustion temperature and emission levels of certain gases allows for the possibility of planning corrective actions to minimize their negative impact on the surroundings. Optical fiber technology is well suited to this purpose and here we describe the main attributes and results obtained from a fiber optic sensing system projected to gather data on distributed temperature and gas emissions in these harsh environments.

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“…a. Close the regulating valve (2), open the coal pyrophoricity measuring instrument (1) in which the coal samples will burn and produce gas. b.…”

Section: Monitoring System and Operationmentioning

confidence: 99%

“…These products of the incomplete combustion of carbonaceous material are mainly formed by internal combustion engines, blasting and spontaneous combustion in coal mines. Oxidation of coal takes place after four stages [1]: 1) physical adsorption of oxygen, resulting in temperature increase; 2) chemical sorption (over 50°C), producing oxygenated hydrocarbons or peroxy-complexes; 3) decomposition of oxygenated hydrocarbons when self-heating temperature is reached (over 70°C), with concurrent oxidation of unaltered coal matter; and 4) spontaneous combustion may then occur if all the above processes result in temperatures higher than 150°C, typically referred to as the ignition threshold. This ignition threshold seems to depend on coal rank, with values around 130°C for the lowest rank, and probably even lower values for peat.…”

Section: Introductionmentioning

confidence: 99%

Terahertz Measurement of Indicator Gas Emission From Coal Spontaneous Combustion at Low Temperature

Wang¹,

Wang²,

Shao³

et al. 2013

Ecological Chemistry and Engineering S

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Coal spontaneous combustion is an extremely complicated physical and chemical changing process. In order to improve the indicator gases detection technology and coal spontaneous combustion monitoring, a novel forecast method for toxic gases emission from coal oxidation at low temperature is presented in this paper. The experiment system is setup combined with frequency-domain terahertz technology and coal temperature programming device. The concentration curves of carbon monoxide and sulphur dioxide gases from coal spontaneous combustion are estimated according to molecule terahertz spectra. The influences of coal rank and oxygen supply on coal spontaneous combustion characteristics are discussed. Both carbon monoxide and sulphur dioxide gases absorption spectra show the characteristic equi-spaced absorption peaks. Results demonstrate that under the condition of lean oxygen, there exists a critical oxygen concentration in the process of coal oxidation at low temperature. Comparing with Fourier infrared spectrum testing, the presented method is highly accurate and more sensitive, especially suitable for early-stage monitoring of the indicator gases produced by coal spontaneous combustion.

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The spontaneous combustion of coal and its by-products in the Witbank and Sasolburg coalfields of South Africa

Cited by 284 publications

References 53 publications

Glycerol effect on the inhibition of spontaneous combustion of subbituminous coal

Glycerol effect on the inhibition of spontaneous combustion of subbituminous coal

ECOAL Project—Delivering Solutions for Integrated Monitoring of Coal-Related Fires Supported on Optical Fiber Sensing Technology

Terahertz Measurement of Indicator Gas Emission From Coal Spontaneous Combustion at Low Temperature

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