Six miners have died and another five are in a serious condition in hospital after being overcome by methane gas at the Pozo Emilio del Valle coal mine in the Pola de Gordón municipality in León Province, northwest Spain. The workers encountered a pocket of gas at about 2.00 pm local time (1.00 pm GMT) on Monday 28 October 2013. The workers were quickly removed from the site by a second team of miners, and were treated by a mobile intensive care unit at the site. An investigation into the accident will begin once the mine has been fully ventilated.
Miners' relatives gathering outside the Pozo Emilio del Valle to wait for news. J.Casares/EFE.
Coal is formed when buried organic material, principally wood, in heated and pressurized, forcing off hydrogen and oxygen (i.e. water) and leaving more-or-less pure carbon. Methane is formed by the decay of organic material within the coal. There is typically little pore-space within coal, but the methane can be trapped in a liquid form under pressure. Some countries have started to extract this gas as a fuel in its own right. When this pressure is released suddenly, as by mining activity, then the methane turns back to a gas, expanding rapidly causing, an explosion. This is a bit like the pressure being released on a carbonated drink; the term 'explosion' does not necessarily imply fire in this context, although as methane is flammable this is quite likely.
The approximate location of the Pozo Emilio del Valle coal mine. Google Maps.
See also Turkish miner killed by underground fire, Three workers killed by gas at German potash mine, Swedish miners rescued from underground fire, Worker killed at Irish lead and zinc mine and Disaster at Gleision Colliery, Godre'r Graig, West Glamorgan.
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