Spontaneous combustion

From the time coal was first mined there have been difficulties. How to support the roof, getting fresh air to the face, mining economically, transporting the coal, seam gases dilution, fires prevention, coal dust problem, explosive outbursts, spontaneous combustion, collapse of overburden etc. Disaster in general is a event or series of event, which gives rise to casualties and damage or loss of life, properties, environment on such a scale which is beyond the normal capacity of the affected community to cope with. Disaster is also sometimes described as a " catastrophic situation in which the normal pattern of life or ecosystem has been disrupted and extra –ordinary emergency interventions are required to save and preserve lives and environment ". A mining disaster is defined as " accident with 10 or more fatalities ". However, it may also be defined as " an unexpected, sudden occurrence, including in particular a major emission of gas, fire, explosion or inundation, resulting from abnormal developments in course of mining activity, leading to a serious dangers to workers, public or the environment, whether immediate or delayed, inside or outside the mine or involving one or more hazardous substances ". There may also be an emergency which may not cause loss of life, but may result in trapping of workers, or affecting persons requiring emergency actions as in case of a disaster. These incidents have potentials of a disaster in the mine. With these concepts in the background, the present study has been carried out in context with the Chasnalla Group of Mines, ISP, and SAIL.

The reactions of chlorine atoms and activated carbon have been studied over the temperature range of 200–400 °C using an isothermal flow reactor in conjunction with 337 nm laser photolysis of Cl2. These studies have shown that carbon tetrachloride is the major product, with chloroform, methylene chloride, and methyl chloride being formed in progressively decreasing yields. Trace quantities of methane, ethane, and dichloroethylenes were also observed. Mechanisms of carbon fragmentation by successive addition of chlorine atoms are proposed. The formation of small chlorinated hydrocarbons by the direct reaction of chlorine with carbon may be a key link in both the de novo and precursor pathways of formation of PCDD/F.

Spontaneous combustion occurs when an object self-ignites. The cause may be chemical, as when lithium oxidises explosively in water, or biological, as when a haystack catches fire due to heat generated from bacterial fermentation. There is no scientific evidence that the human body can self-ignite. However, spontaneous human combustion (SHC) as an alleged cause of death has a long and controversial history. If true, the mechanism of ignition is mysterious and challenges what we know about the human body.....

The main objective of researches was assessment of a stress-strain state of
regional parts of a rock massif and coal pillars at various seam thickness, panel width
and a mining depth. Dependences of extent of zones of limit state on the main
geological and mining parameters are established. The increased hazard of mining of
thick flat seams with the increased width of longwall panel is shown.
Recommendations about decrease in the endogenous fire hazard connected with
disintegration of regional parts of seam and chain enter panel coal pillars are made

Описан процесс математического моделирования нагрева пирофорного слоя – одной из причин взрывов и пожаров в нефтегазовой отрасли. Приведены некоторые условия, влияющие на процесс нагрева слоя пирофорных отложений. Приведена система уравнений, моделирующая процесс нагрева пирофорного слоя. Представлены расчётные данные математической и сравнены с экспериментальными.
The heating of layer of pyrophoric deposits as one of the cause of explosions and fires in oil and gas industry is described. It is reported that thickness of pyrophoric deposits, steel substrate and oxygen concentration in the gas phase influence on the process of heating a layer of pyrophoric deposits. A mathematical model of a reservoir is described and an approximate temperature distribution in the layer of pyrophoric deposits is shown. A system of equations, simulating a onedimensional process for heating a pyrophoric layer, is given, the heat equation is used as the basic equation. The cooling conditions for the tank, both on the inside and outside are added. The calculated data of the mathematical model on the heating of the pyrophoric layer in time, after reaching the maximum calculated self-heating temperature for various thickness of pyrophoric deposits are represented and compared with experimental ones. The temperature distribution in the layer of pyrophoric deposits is shown.

Surgical fires require an oxygen-enriched environment, a flammable substrate, and an ignition source. We hypothesized ambient oxygen concentration is proportional to the latency time to combustion and the incidence of surgical fires that are detected. We examined latency time and number of events, utilizing the VanCleave et al model of intraoral fire ignition under 60, 80, and 100% oxygen concentration and flow rates of 4 and 10 L/min. Results demonstrated that ambient oxygen concentration and flow rate correlated positively to the initiation of combustion. The number of combustion events with 60% oxygen was significantly lower than with both 80% ( p = .0168) and 100% ( p = .002). Likewise, the number of events with 80% oxygen was significantly lower than with 100% oxygen ( p = .0019). Flow rate has a significant effect on the time to the first event ( p = .0002), time to first audible pop ( p = .0039), and time to first flash or fire ( p < .0001). No combustion occurred at oxyge...

Fabricated from the end of the 18th century, popularized after 1830 by French soldiers returning from Algeria, crowned the green fairy of the Parisian boulevards around 1860, the absinthe dominates the fin-de-siècle imagination as the principal means of transport “anywhere out of the world”. This article resumes the paradoxical mythology of this beverage that appears in French novels in the second half of the 19th century. Octave Féré, Jules Cauvain and the Goncourt brothers
give a warning against its pernicious power, while Emile Zola’s attitude to the absinthe is more ambiguous. The magical potential of the green fairy seems to be tempting the father of naturalism who mixes science and mythology, the probable and the grotesque, the strict laws of heredity and the supernatural lightness of a blue flame coming from the “spontaneous combustion".

Spoil tips are anthropomorphic terrain structures built out of leftover materials fromunderground or open pit mining. Usually the term spoil tips refers to those build outof unusable particles from coal exploration. As such they consist mostly of slate andvarious types of sandstone or mudstone. But also include some amount of coal and,what is more important, coal dust. Fires of spoil tips are dangerous to the environ-ment and humans. They can cause degradation of air, and water qualities. Sometimesdegradation to the environment can be irreversible. The presented survey was done in two stages. the first included creating a general terrain model. This was done with the use of long range laser scanner. The second step was a more detailed analysis of spatial and temperature conditions. Two measuring seasons ware performed. The first included a survey made with a short range laser scanner and a hand-held inferred camera. The obtained point cloud was supplemented with temperature value with the useof software and hardware provided by the authors. The visualization of 3D discreetthermal model was done in Bentley MicrioStation. The second included a usage of Z+F IMAGER 5010 laser scanner equipped with T-Cam Rev 1.0 thermal camera in-sole. A new and unique device that connects laser scanner with infrared camera. Thisseason also provide a point cloud with attached temperature value of measured points.This article provides the description of those two methods including a comparison of their effectiveness and costs. It also describes the heat conditions occurring on spoiltip of Lubelski Węgiel „Bogdanka” S.A coal mine surveyed in December 2015.
spoil tips, infrared, spontaneous combustion, monitoring, thermal DTM

Adiabatic oxidation tests were carried out on pulverized coal samples. Spontaneous heating potential was measured according to total temperature rise (TTR) while considering temperature rise versus time curves. The effect of moisture content of coal, relative humidity of airflow, airflow rates, coal size fractions, nitrogen suppression and prior oxidation were studied. Results demonstrated that humidity of air is an important factor in deciding whether heating will progress or not. Particle size affected the TTR values whereby oxidation rate of coal increased with decrease in particle size up to a critical diameter below which dependence ceases. A relationship was derived between rate of oxidation and oxygen concentration. Aged or pre-oxidized coals had shown lower TTR values and is shown to be function of initial temperature and time.

The main objective of researches was assessment of a stress-strain state of
regional parts of a rock massif and coal pillars at various seam thickness, panel width
and a mining depth. Dependences of extent of zones of limit state on the main
geological and mining parameters are established. The increased hazard of mining of
thick flat seams with the increased width of longwall panel is shown.
Recommendations about decrease in the endogenous fire hazard connected with
disintegration of regional parts of seam and chain enter panel coal pillars are made

A rough estimate of the annual amount of sulfur, arsenic, mercury and fluoride emission from spontaneous combustion of coal gangue in China was determined. The weighted mean concentrations of S, As, Hg, and F in coal gangue are 1.01%, 7.98, 0.18, and 365.54 mg/kg, respectively. Amounts of S, As, Hg, and F emissions from coal gangue spontaneous combustion show approximately 1.13 Mt, and 246, 45, and 63,298 tons in 2013, respectively. The atmospheric release amount of sulfur from coal gangue is more than one tenth of this from coal combustion, and the amounts of As, Hg, and F are close to or even exceed those from coal combustion. China's coal gangue production growth from 1992 to 2013 show an obvious growth since 2002. It may indicate that Chinese coal gangue has become a potential source of air pollution, which should be included in emission inventories.

Representative coal samples were collected from different coal seams of the Chirimiri coalfield which covered the entire stratigraphic sequence. These samples were tested for Chemical analysis, Crossing Point Temperature (CPT), Petrography, Infrared studies (IR) and ...

Representative coal samples were collected from different coal seams of the Chirimiri coalfield which covered the entire stratigraphic sequence. These samples were tested for Chemical analysis, Crossing Point Temperature (CPT), Petrography, Infrared ...

Surgical fires require an oxygen-enriched environment, a flammable substrate, and an ignition source. We hypothesized ambient oxygen concentration is proportional to the latency time to combustion and the incidence of surgical fires that are detected. We examined latency time and number of events, utilizing the VanCleave et al model of intraoral fire ignition under 60, 80, and 100% oxygen concentration and flow rates of 4 and 10 L/min. Results demonstrated that ambient oxygen concentration and flow rate correlated positively to the initiation of combustion. The number of combustion events with 60% oxygen was significantly lower than with both 80% ( p = .0168) and 100% ( p = .002). Likewise, the number of events with 80% oxygen was significantly lower than with 100% oxygen ( p = .0019). Flow rate has a significant effect on the time to the first event ( p = .0002), time to first audible pop ( p = .0039), and time to first flash or fire ( p < .0001). No combustion occurred at oxyge...

Chem. Eng. Comm. 1991, Vol. 105, pp. 255-278 Reprints available directly from the publisher. Photocopying permitted by license only. @ 1991 Gordon and Breach Science Publishers SA Printed in the United States of America ... SELF-IGNITION AND CONVECTION ...