Thermogravimetric analysis of the co combustion of coal and polyvinyl chloride. We have even seen a similar problem in sugar cane bagasse at the 2017 cape town misg 1. This is a combustion in which fuel burns suddenly and produces heat with the help of external heat or pressure. This book aims to understand, analyze and mitigate the harmful impacts of spontaneous coal combustion in underground mines, a thermal phenomenon that triggers fires and explosions threatening the safety of mine workers globally. However, these are materials that contain the fuel for spontaneous combustion in coal mines. Manager sustainability and corporate affairs 3 implementation and operation 3. The process changes the internal heat profile of the material leading to a rise in temperature. These give a wideranging insight into the causes and control of spontaneous combustion in coal mining and coal storage. The impact of bleederless ventilation practices on other mine design parameters, such as ground con trol, methane control, ventilation, and monitoring, is considered. Spontaneous combustion in open cut coal mines acarp. Spontaneous combustion of coal has been extensively studied in underground and opencast mines of south african mines using smallscale test.
Sep 20, 2012 surface coal mine workers were exposed to toxic gases, associated with spontaneous combustion, including carbon monoxide and sulphur dioxide. Paper open access study on spontaneous combustion of boiler. According to the national fire protection association nfpa. The primary method used for the detection of spontaneous combustion in underground coal mines is the analysis of the gaseous products of coal oxidation using a gas analyzer or a gas chromatograph. In addition, mines in jharia, jharkhand are famous for their rich coal resources, but records show nearly 70 fires have been burning for over 100 years dating back to 1916. Schematic showing spontaneous combustion of large amount of coal stock, a, b and c. In coal mines, for spontaneous combustion to occur, three conditions must be satisfied. India has the largest concentration of coal fires, and it is estimated that 80% of those fires started due to spontaneous combustion. Assessing and managing spontaneous combustion of coal.
Spontaneous combustion wikimili, the free encyclopedia. Spontaneous combustion that leads to coal fires in power plants can cause major destruction. The r 70 values obtained are strongly coal rank dependent and are affected by the intrinsic. Recent heating incidents in australia further highlight the need of improving current knowledge and practices of sponcom management to ensure safety and productivity of coal mines extracting coal seams that are prone to spontaneous heating. Spontaneous combustion of coals and coal shales article pdf available in international journal of mining science and technology 286 may 2018 with 369 reads how we measure reads.
Bleederless ventilation systems as a spontaneous combustion. Coal seams with a history of spontaneous combustion gov. At about 150300 degrees f, it begins to give off minute, but measurable, quantities of gasaerosols, hydrogen, and co2precursors of combustion. The term spontaneous combustion may seem like an idea from a fantasy movie or tabloid newspaper, but in fact, spontaneous combustion is a serious source of fires in home and garage workshops, as well as on farms.
There are thousands of uncontrolled coal fires across the earth, some of which have been burning for thousands of years. Spontaneous combustion of coal characteristics, evaluation. There has been a wealth of literature in the past few decades explaining the spontaneous combustion of coal. Spontaneous combustion iea clean coal centre assessing and managing spontaneous combustion of coal 10 2 spontaneous combustion all coals oxidise when newly exposed to air, especially during and after mining. The selfheating of coalshale has been reported to be the likely source of spontaneous combustion in selected bands of a coal seam, highwalls and spoil heaps in witbank, south africa as shown in fig. Spontaneous heating of coal occurs when sufficient oxygen is available to sustain the low temperature reaction of coal with oxygen but the heat produced by the coal oxidation is not adequately dissipated by conduction or convection. There is no sufficient information to predict the spontaneous heating of coal shales. 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 selfheating properties of coal. In the united states between 1978 and 1988, approxi. Spontaneous combustion of coals and coalshales sciencedirect. Spontaneous combustion, or selfheating, is most common in.
Stages of severity and risk of spontaneous combustion newcastle coal, 2014. Nov 03, 2014 fires occurring due to spontaneous combustion is a function of. For spontaneous combustion to occur in colliery spoil, three things must be present. Fire administration, spontaneous fires are one of the leading causes of fires in agricultural storage facilities i. Spontaneous combustion description underground coal. Spontaneous combustion sponcom of coal remains a major safety issue for underground coal mining operations. Spontaneous combustion continues to pose a hazard for u. Spontaneous human combustion shc is the concept of the combustion of a living or recently deceased human body without an apparent external source of ignition. Spontaneous combustion in coalhow coal selfignites the coals temperature begins to climb above ambient. This tends to be more of a problem in lower rank coals. Spontaneous combustion is an oxidation reaction that occurs without an external heat source. Based on the measurement, the fire is 685 m long, 25 m wide, and the whole fire area is about 8490 m 2. Spontaneous combustion liability between coal seams. Pdf spontaneous combustion of coal is an important problem in mining and storage, in terms of both safety and economics.
Spontaneous combustion of coal is a fire initiated by the oxidation of coal. This is because coal reacts with oxygen in the air and an exothermic reaction. In addition to reported cases, descriptions of the alleged phenomenon appear in literature, and both types have been observed to share common characteristics in terms of circumstances and the remains of the victim. It was divided into three parts including north firefield, middle firefield, and. Spontaneous combustion of coal is a serious problem that often occurs in the coal industry jones and townend, 1945.
The relative propensity of coal to undergo selfheating can be established by different methods. Spontaneous combustion of coal is the process of self heating resulting eventually in its ignition without the. Us4170456a us05962,816 us96281678a us4170456a us 4170456 a us4170456 a us 4170456a us 96281678 a us96281678 a us 96281678a us 4170456 a us4170456 a us 4170456a authority us united states prior art keywords coal char spontaneous combustion char temperature coal prior art date 19781122 legal status the legal status is an assumption and is not a legal conclusion. Hot spot forming process with accumulating heat and shrinking. Paper open access study on spontaneous combustion of. The selfheating process depends on many factors including coal rank, temperature, airflow rate, the porosity of the coal pile, ash and moisture content of the coal, humidity as well as particle size of coal. Co and co2 emissions from spontaneous heating of coal. Spontaneous combustion occurs not just in coal but in other piles of materials including hay, compost, manure and pistachio shells. The risk of an explosion ignited by a spontaneous combustion fire is also present in those mines with. Given the right kind of coal, oxygen, and a certain temperature and moisture content, coal will burn by itself. Combustion in a fire produces a flame, and the heat produced can make combustion selfsustaining. Spontaneous combustion is a complex physical and chemical process, caused by the chemical reaction between carbonaceous materials coal and coal shale and oxygen in the air. The primary method used for the detection of spontaneous combustion in underground coal mines is the analysis of the gaseous products of coal oxidation using a.
Kct spontaneous combustion management protocol authorised by. Coal in bulk should be carefully stored to avoid spontaneous combustion. Co and co2 emissions from spontaneous heating of coal under. Preventing spontaneous combustion coal fires involves attention to many different factors. Spontaneous coal combustion according to a study supported by the cdc. Coal must be present in a form which can oxidize readily at ambient temperature. Combustion, or burning, is a hightemperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke.
Spontaneous combustion of coal is an important problem in mining and storage, in terms of both safety and economics. An illustration of the fundamental phenomena occurring in the coal oxidation process wang et al. Spontaneous combustion of coals and coalshales article pdf available in international journal of mining science and technology 286 may 2018 with 369 reads how we measure reads. Spontaneous combustion can result and make mining difficult research conducted by coaltech mining companies guidelines compiled for use by coal mines recent mining operations report successful control of spontaneous combustion through application of buffer blasting, use of sand to cover highwalls etc. Spontaneous combustion results from selfheating which is caused mainly by the oxidation of coal and other carbonaceous materials. Pdf modelling spontaneous combustion of coal edvin. Coal has a tendency to selfheat due to the autooxidation of its compounds, making spontaneous combustion the most common cause of uncontrolled burning. Spontaneous combustion was discovered in 2003 in the no.
Pdf modelling spontaneous combustion of coal researchgate. Since gas to solid combustion reactions are slower than gas to gas reactions, high fixed carbon content indicates that the coal will require a long combustion time. Combustion is often a complicated sequence of elementary radical reactions. Previous works from many disciplines attempted to understand the mechanism of spontaneous combustion of coal. As the temperature increases furtherat about 600700 degrees f. In order to assist individuals who wish to obtain a deeper understanding of spontaneous combustion, the literature survey of project 3. What causes spontaneous combustion today i found out.
Study on the oxidation and release of gases in spontaneous coal combustion using a dualspecies sensor employing laser absorption spectroscopy. Spontaneous combustion or spontaneous ignition, as it is often called, is the occurrence of fire without the application of an external heat source. Mar 23, 2015 coal seams with a history of spontaneous combustion. The r 70 test provides a quick and accurate measure of the intrinsic reactivity of coal to oxygen and is backed by an extensive database of results from locations around the world that can enable a direct comparison to be made between coals of similar spontaneous combustion propensity. Although several theories have been proposed to account for the phenomenon wang, 2006. Fires occurring due to spontaneous combustion is a function of.
However in coal mines, coals spoken of as being liable to spontaneous combustion are those coals which will develop to an open fire under specific conditions. Dec 19, 20 spontaneous coal combustion according to a study supported by the cdc. Largescale studies of spontaneous combustion of coal. This book aims to understand, analyze and mitigate the harmful impacts of spontaneous coal combustion in underground mines, a. The occurrence of spontaneous combustion is not limited to coal but the phenomenon is known to take place in a number of coalshale, pyritic black shale and coal refuse kim and chaiken 1990. These methods are well established in their usage, but the fact that no particular test method has become a standard to predict the spontaneous combustion liability indicates. Mining in a manner which removes spontaneous combustion is one of the main reasons for mining at mcc. Spontaneous heating of coal occurs when sufficient oxygen is available to sustain the low temperature reaction of coal with oxygen but the heat produced by the coal oxidation. List of coal seams which have been know to suffer from occurrences of spontaneous combustion and. Serious incidents of spontaneous combustion have been reported as a result of selfheating of reactive coalshales. This is a combustion in which fuel burns spontaneously without any external heat. Powder river basin prb coal was first used in 1974 and, although the new.
Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by selfheating increase in temperature due to exothermic internal reactions, followed by thermal runaway self heating which rapidly accelerates to high temperatures and finally, autoignition. Combustion is a rapid chemical reaction in which fuel reacts with oxygen to produce heat. Based on experimental and theoretical research findings, the book emphasizes. Carbondioxide stored in bulk should be used when fire is imminent and the hatches should be cooled from the outside with water sprays and not opened up until firefighting tugs or port is reached. These releases exposed some mine workers to harmful levels of gases, including carbon monoxide co and sulphur dioxide so 2 which are the main gases associated with spontaneous combustion in queensland surface coal mines. This can eventually lead to open flame and burning of the material. Strictly speaking, it is the oxidation process that is combustion and, to the extent that all coals oxidize, all coals are prone to spontaneous combustion. Completion of coal combustion will depend upon how the carbon rings. The risk of an explosion ignited by a spontaneous combustion fire is also present in those mines with appreciable levels of accumulated methane. Lopez, 1998, the definitive mechanism of coal spontaneous combustion is still unknown. The following tables presents a list of coal seams which have been known to suffer from occurrences of spontaneous combustion and are consequently regarded as at high risk of succumbing to spontaneous combustion when being entered, worked or disturbed. Coal seams with a history of spontaneous combustion. The spontaneous combustion of coal in high caving regions is a kind of internal fire in a specific environment of underground coal mines.
Indian coal fires were first documented in coal fields located in raniganj back in 1865. In 2012, several surface coal mines experienced the release of toxic gases associated with spontaneous combustion. Pdf spontaneous heating and fire in coal mines researchgate. Thermogravimetric analysis of the cocombustion of coal and polyvinyl chloride. Propensity of coal to selfheat united states energy. All fires, including those ignited spontaneously, require three elements. On ships regular testing of the temperatures of the hold should be done. Causes of spontaneous combustion of coal and its prevention. Effect of inorganic chloride on spontaneous combustion of coal. Circuits arerunfromthe232tubestoageneralannunciatorinthesuperin tendentsoffice. Among the most critical are the type, age, and composition of coal, how it is stored, and how it is used. If the heat generated by this reaction is trapped, such as in a spoil pile, the temperature of the material will begin to rise and if unchecked may ultimately ignite.
Normally, we think of a source of heat as something with an open flame, but, in spontaneous combustion, there is no flame causing the heat. The spontaneous combustion of coal in colliery spoil heaps may be reduced if oxygen is prevented from mixing with the waste and if there is an excess of moisture to contain any heating that may occur. The principles that control spontaneous combustion are similar in all cases, irrespective of the material that is involved. Spontaneous combustion liability of coal and coalshale. Unless handled correctly, the results can be catastrophic in both damage to power plant assets and, in a worse case scenario, the loss of human life. Estimating the spontaneous combustion potential of coals. Us4170456a inhibiting spontaneous combustion of coal.
Due to chemical, biological, or physical processes, combustible materials selfheat to a temperature high enough for ignition to occur. Pdf spontaneous combustion in beds of coal particles. This event causes significant economic and environmental effects. The auto oxidation of coal ultimately leads to spontaneous combustion which is the major root cause for the disastrous of coal mine in leading and coal producing. Spontaneous combustion, callide coal, hot spot development, moisture transfer introduction spontaneous combustion of coal is an important problem in its mining, long distance transportation, and storage, in terms of both safety and economics. Spontaneous combustion of coal linkedin slideshare.