Mine fire
From Wikipedia, the free encyclopedia
A mine fire or coal fire is the underground smouldering of a coal mine. Such fires have economic, social and ecological impact.
Mine fires can burn for very long periods of time (from months to centuries), until the seam in which they smoulder is exhausted. They propagate in a creeping fashion along mines shafts and cracks. Because they are underground, they are extremely difficult and costly to reach and put out. There is a strong similarity between mine fires and peat fires.
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[edit] Origins
Mine fires may begin as a result of an industrial accident, generally involving a gas explosion. Historically, some mine fires were started when bootleg mining was stopped by authorities, usually by blowing the mine up. Many recent mine fires have started from people burning trash in a landfill that was in proximity to abandoned coal mines, including the much publicized Centralia, Pennsylvania fire, which has been burning since 1962. Of the hundreds of mine fires in the United States burning today, most are found in the state of Pennsylvania.
Some fires along coal seams are natural occurrences. Some coals may self-ignite at temperatures as low as 40 °C (104 °F) in the right conditions of moisture and grain size. Wildfires (lightning caused or others) can ignite the coal closer to the surface or entrace, and the smouldering fire can spread through the seam, creating subsidence that may open further seams to oxygen. Prehistoric clinker outcrops in the American West are the result of prehistoric coal fires that left a residue that resists erosion better than the matrix, leaving buttes and mesa. It is estimated that Australia's Burning Mountain, the oldest known coal fire, has burned for 6,000 years.[1]
Globally, thousands of inextinguishable mine fires are burning, especially in China and India, where poverty, lack of government regulations and runaway development combine to create an environmental disaster. Modern strip mining exposes smoldering coal seams to the air, revitalizing the flames.
Rural Chinese in coal-bearing regions often dig coal for household use, abandoning the pits when they become unworkably deep, leaving highly combustible coal dust exposed to the air. Using satellite imagery to map China's coal fires resulted in the discovery of many previously unknown fires. The oldest coal fire in China in Baijigou is said to have been burning since the Qing Dynasty[2]
[edit] Enviromental impact
Besides destruction of the affected areas, coal fires emit gases that many say contribute to global warming. China's coal fires, which consume an estimated 20 – 200 million tons of coal a year, make up as much as 1 percent of the global carbon dioxide emissions from fossil fuels.[1]
[edit] Extinguishing coal fires
The task of extinguishing underground coal fires, sometimes exceeding temperatures of 540 °C (1,000 °F), is both highly dangerous and very expensive.[1]
Successes include the 2004 mine fire at the Liuhuanggou colliery near Urumqi in China's Xinjiang province. It had been burning since 1874.
[edit] List of mine fires
[edit] External links
- Encyclopedia of Earth: Coal fires
- "Coal fires - A natural or man made hazard?" (site about coal mine fires from Anupma Prakash, of the Univ. of Alaska-Fairbanks)
- Centralia, Pennsylvania Mine fire
- Centralia Mine Fire (from roadsideamerica.com)
- Welcome to Centralia
[edit] References
- ^ a b c Krajick, Kevin. "Fire in the Hole", Smithsonian Magazine, 2005-05-01, pp. 54ff. Retrieved on January 16, 2007.
- ^ [1]
- Kuenzer, C.; Zhang, J.; Tetzlaff, A.; van Dijk, P.; Voigt, S.; Mehl, H.; Wagner, W. (2007). "Uncontrolled coal fires and their environmental impacts: Investigating two arid mining regions in north-central China". Applied Geography 27: 42-62.
- "Satellites track the fires raging beneath India", New Scientist, 2006-07-18, pp. 25ff. Retrieved on January 16, 2007.
