"sold to refineries the same as oil. The C2 through C5 hydrocarbons (ethane, propane, butane, and pentane) are known as natural gas liquids (NGLs), and remain in gaseous form until they are extracted at a gas processing plant. The division between the two classes is not perfect: some hexane, and heptane remain in the gas to be separated out as NGLs, while some butane and pentane, may separate out with the condensate. Natural gas which contains NGLs is called ""wet gas."" Gas which naturally contains no NGLs, or gas from which the NGLs have been removed, is called ""dry gas."""
"Afterdamp Afterdamp is the toxic mixture of gases left in a mine following an explosion caused by firedamp, which itself can initiate a much larger explosion of coal dust. It consists of carbon dioxide, carbon monoxide and nitrogen. Hydrogen sulfide, another highly toxic gas, may also be present. However, it is the high content of carbon monoxide which kills by depriving victims of oxygen by combining preferentially with haemoglobin in the blood. Afterdamp was the deadly gas which caused the majority of casualties in the many pit disasters of the British coalfields, such as the Senghenydd colliery disaster and elsewhere"
"firedamp, a dangerous and explosive mixture of gases (chiefly methane). Firedamp is explosive at concentrations between 4% and 16%, with most violence at around 10%. In addition, there was another potential contributing factor in the bituminous coal – this was iron sulfide, also known as pyrite, that was likely present. The presence of pyrites presents two additional risk factors. The first involves oxidation. Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally had serious problems with spontaneous combustion in the mined-out areas of the mine. This process can result from the disruption caused by"
"anthracite, bituminous and steam coals—the latter a grade between the two comprising a hard coal without the coking elements. Some of the region's coal seams contained high quantities of firedamp, a highly explosive gas consisting of methane and hydrogen, and were therefore prone to explosions; firedamp rises into the higher points of workings, including cavities or, as at Senghenydd, when the seams were being mined in an upward gradient. An additional danger of firedamp is afterdamp, a poisonous mixture of gases left after an explosion, primarily constituted of carbon dioxide, carbon monoxide and nitrogen. The carbon monoxide combines with haemoglobin"
"other damps include ""blackdamp"" (carbon dioxide and other gases), poisonous, explosive ""stinkdamp"" (hydrogen sulfide), with its characteristic ""rotten egg"" odour, and the insidiously lethal ""afterdamp"" (carbon monoxide and other gases) produced following explosions of firedamp or coal dust. Firedamp is explosive at concentrations between 4% and 16%, with most explosions occurring at around 10%. It caused much loss of life in coal mines before the invention of the Geordie lamp and Davy lamp. Even after the safety lamps were brought into common use, firedamp explosions could still occur from sparks produced when coal contaminated with pyrites was struck with metal"
"in the world. Such disasters continue to afflict working mines, especially in mainland China. Animal sentinels, such as mice or canaries, are more sensitive to the gas than humans, so will give a warning to miners. Canaries were introduced into British collieries in the 1890s by John Scott Haldane, the noted physiologist. Gas detectors are available now which detect toxic gases such as carbon monoxide at very low levels. They are widely available to protect domestic premises. The levels of gas detection depend on the methods used. Afterdamp Afterdamp is the toxic mixture of gases left in a mine following"
"entered the two mines twenty-five minutes after the initial explosion. The biggest threats to rescuers are the various fumes, particularly “blackdamp”, a mix of carbon dioxide and nitrogen that contains no oxygen, and “whitedamp”, which is carbon monoxide. The lack of breathing apparatus at the time made venturing into these areas impossible. Rescuers could only stay in the mine for 15 minutes at a time. In a vain effort to protect themselves, some of the miners tried to cover their faces with jackets or other pieces of cloth. While this may filter out particulate matter, it would not protect the"
"in enclosed environments such as mines, sewers, wells, tunnels and ships' holds. It occurs with particular frequency in abandoned or poorly ventilated coal mines. Coal, once exposed to the air of a mine, naturally begins absorbing oxygen and exuding carbon dioxide and water vapor. The amount of blackdamp exuded by a mine varies based on a number of factors, including the temperature (coal releases more carbon dioxide in the warmer months), the amount of exposed coal, and the type of coal, although all mines with exposed coal produce gas. Blackdamp is considered a particularly pernicious type of damp (especially in"
"mine in particular can be very dangerous. Old mine workings, caves, etc. are commonly hazardous simply due to the lack of oxygen in the air (a condition in mines known as blackdamp). Blackdamp is a deadly killer which provides no warning to any individual or group of individuals entering such an environment. Every year, dozens are injured or killed in recreational accidents on mine property. It is only fair to note, however, that the majority of the deaths are unrelated to mine exploration. Drownings in open quarries and ATV accidents on abandoned mine properties are the main cause of accidental"
"and the start of frank asphyxiation (and rapid unconsciousness) can be as short as seconds. Thus, if the warning signs are missed, a large number of miners can be rapidly incapacitated in the same short period of time, leaving no one to summon help. In addition to the danger inside the mine, blackdamp can be ""exhaled"" in large quantities from mines (especially long-abandoned coal mines with few outlets for escaping gas) during sudden changes in atmospheric pressure, potentially causing asphyxiation on the surface. The gas mixture has been responsible for many deaths among underground workers, especially miners. For example, the"
"in the bloodstream to form carboxyhemoglobin, which prevents the blood cells carrying oxygen, which can result in suffocation by lack of oxygen or anoxia. If survivors from an explosion are not rescued quickly, they face the possibility of being killed by the gas. The presence of firedamp contributed to a higher-than-average proportion of accidents: between 1880 and 1900 South Wales accounted for 18% of Britain's miners, but 48 per cent of all UK mining deaths occurred in the region. As coal output from British collieries reached its peak in 1913 there was a correspondingly large number of accidents around this"
"carbon dioxide and nitrogen as ""blackdamp,"" ""choke damp"" or ""stythe."" Before more effective technologies were developed, miners would frequently monitor for dangerous levels of blackdamp and other gases in mine shafts by bringing a caged canary with them as they worked. The canary is more sensitive to asphyxiant gases than humans, and as it became unconscious would stop singing and fall off its perch. The Davy lamp could also detect high levels of blackdamp (which sinks, and collects near the floor) by burning less brightly, while methane, another suffocating gas and explosion risk, would make the lamp burn more brightly."
"tools. The presence of coal dust in the air increased the risk of explosion with firedamp, and indeed could cause explosions itself. The Tyneside coal mines in England had the deadly combination of bituminous coal contaminated with pyrites, and a great number of lives were lost in accidents due to firedamp explosions, including 102 dead at Wallsend in 1835. The problem of firedamp in mines had been brought to the attention of the Royal Society by 1677, and in 1733 Sir James Lowther, reported that as a shaft was being sunk for a new pit at Saltom near Whitehaven, a"
"could not be met by the museum. The water would take years to rise to the level of the old Chatterley Whitfield tour at 700 feet (213 metres) below ground, but there was another problem, coal gives off methane (Firedamp), a gas formed by the decay of plants which produced the coal millions of years ago. The gas is absorbed and adsorbed within the coal, but mining disturbs the ground and releases the gas. The gas is colourless and highly explosive. If there is sufficient in the air it reduces the amount of oxygen and causes suffocation. Methane is lighter"
"explosive natural gases, especially firedamp or methane, dust explosions, collapsing of mine stopes, mining-induced seismicity, flooding, or general mechanical errors from improperly used or malfunctioning mining equipment (such as safety lamps or electrical equipment). Use of improper explosives underground can also cause methane and coal dust explosions. On April 26, 1942, in the Benxihu (Honkeiko) Colliery (coal mine), what is believed to have been the world's worst mining disaster took place, killing 1,549 miners. The disaster occurred in an area that is now within the bounds of modern-day China, but was then in a portion of China occupied by the"
"safety lamp is merely a specially designed lantern with a flame that is designed to automatically extinguish itself at an oxygen concentration of approximately 18% (normal atmospheric concentration of oxygen is c. 21%). This low detection threshold gives miners an unmistakable warning and allows them to escape before any potentially incapacitating effects are felt. Blackdamp Blackdamp (also known as stythe or choke damp) is an asphyxiant, reducing the available oxygen content of air to a level incapable of sustaining human or animal life. It is not a single gas but a mixture of unbreathable gases left after oxygen is removed"
"through alleged German sympathies, he shifted into working with victims of gas warfare and developed oxygen treatment including the oxygen tent. He investigated the principle of action of many different gases. He investigated numerous mine disasters, especially the toxic gases which killed most miners after firedamp and coal dust explosions. The toxic mixtures of gases found in mines included afterdamp, blackdamp and whitedamp. His description of the way a flame safety lamp can be used to detect firedamp by the increase in height of the flame, and chokedamp by the dying of the flame, is a classic exposition in his"
"mines can poison the workers or displace the oxygen in the mine, causing asphyxiation. For this reason, the U.S. Mine Safety and Health Administration requires that groups of miners in the United States carry gas detection equipment that can detect common gases, such as CO, O, HS, CH, as well as calculate % Lower Explosive Limit. Regulation requires that all production stop if there is a concentration of 1.4% of flammable gas present. Additionally, further regulation is being requested for more gas detection as newer technology such as nanotechnology is introduced. Ignited methane gas is a common source of explosions"
"the same year. Coal production in China is twice that in the US, while the number of coal miners is around 50 times that of the US, making deaths in coal mines in China 4 times as common per worker (108 times as common per unit output) as in the US. Build-ups of a hazardous gas are known as damps: Firedamp explosions can trigger the much more dangerous coal dust explosions, which can engulf an entire pit. Most of these risks can be greatly reduced in modern mines, and multiple fatality incidents are now rare in some parts of the"
"textbook, ""Respiration"". Although electronic gas detectors are now used widely in all coal mines, flame lamps are still used extensively for their ease and simplicity of operation. Electronic gas detectors rely on a catalytic chip which can be poisoned by atmospheric impurities. He identified carbon monoxide as the lethal constituent of afterdamp, the gas created by combustion, after examining many bodies of miners killed in pit explosions. Their skin was coloured cherry-pink from carboxyhaemoglobin, the stable compound formed in the blood by reaction with the gas. It effectively displaces oxygen, and so the victim dies of asphyxia. As a result"
"and much more difficult to detect. However, the most effective gas was mustard gas, introduced by Germany in July 1917. Mustard gas was not as fatal as phosgene, but it was hard to detect and lingered on the surface of the battlefield, so could inflict casualties over a long period. Even if not inhaled, it could slowly burn the skin, but quickly burned via the eyes or any wounds, causing blindness and intense suffering. Mustard gas also had the property of being heavier than air, causing it to sink down hills and therefore down into trenches. Casualties from mustard gas"
"that this was caused by traces of ethanethiol in the gas it was decided to boost the amount of ethanethiol in the gas, to make detections of leaks easier. Ethanethiol is intentionally added to butane and propane (see: LPG) to impart an easily noticed smell to these normally odorless fuels that pose the threat of fire, explosion, and asphyxiation. In the underground mining industry, ethanethiol or ethyl mercaptan is referred to as ""stench gas"". The gas is released into mine ventilation systems to alert mine workers during an emergency. In Ontario, mining legislation dictates that ""The alarm system in an"
"explosive gases the candle would ignite them, often not sparing the boss on the other end. Less dangerous methods are used today such as pumping air into the mine to dilute the levels of dangerous gases (see explosive limit). Fire boss A fire boss is a person employed at a mine or state certified official, responsible for examining a mine for dangers, particularly explosive, poisonous or suffocating gases. Usually the fire boss is the first person to enter a mine, to verify its safety, before a shift crew enters. It may also loosely refer to a foreman or shift manager"
"Blackdamp Blackdamp (also known as stythe or choke damp) is an asphyxiant, reducing the available oxygen content of air to a level incapable of sustaining human or animal life. It is not a single gas but a mixture of unbreathable gases left after oxygen is removed from the air and typically consists of nitrogen, carbon dioxide and water vapour. The suffix ""damp"" is believed to derive from the German word for vapours (""""Dampf""""). The word ""damp"" is used in similar mining terms such as white damp (carbon monoxide), fire damp (typically methane) and stink damp (hydrogen sulfide). Blackdamp is encountered"
"The gas was ignited, and it decomposed to pure metallic arsenic, which, when passed to a cold surface, would appear as a silvery-black deposit. So sensitive was the test, known formally as the Marsh test, that it could detect as little as one-fiftieth of a milligram of arsenic. He first described this test in ""The Edinburgh Philosophical Journal"" in 1836. Henry Goddard at Scotland Yard pioneered the use of bullet comparison in 1835. He noticed a flaw in the bullet that killed the victim and was able to trace this back to the mold that was used in the manufacturing"
"Tear gas Tear gas, formally known as a lachrymator agent or lachrymator (from the Latin ""lacrima"", meaning ""tear""), sometimes colloquially known as mace, is a chemical weapon that causes severe eye and respiratory pain, skin irritation, bleeding, and even blindness. In the eye, it stimulates the nerves of the lacrimal gland to produce tears. Common lachrymators include pepper spray (OC gas), PAVA spray (nonivamide), CS gas, CR gas, CN gas (phenacyl chloride), bromoacetone, xylyl bromide, syn-propanethial-S-oxide (from onions), and Mace (a branded mixture). Lachrymatory agents are commonly used for riot control. Their use in warfare is prohibited by various international"
"air giving every opportunity for explosive mixtures of gas to accumulate. A subsequent Select Committee in 1852 concurred with this view; firedamp explosions could best be prevented by improving mine ventilation (by the use of steam ejectors: the committee specifically advised against fan ventilation), which had been neglected because of over-reliance on the safety of the Davy lamp. The practice of using a Davy lamp and an candle together was not entirely absurd, however, if the Davy lamp is understood to be not only a safe light in an explosive atmosphere, but also a gauge of firedamp levels. Of course,"
"and items they purchased from company stores. Many coal companies paid miners with company scrip (private money), good only at company-owned stores. In addition to the poor economic condition, safety in the mines was a great concern. West Virginia fell behind other states in regulating mining conditions, and between 1890 and 1912, had a higher mine death rate than any other state. West Virginia was the site of the worst coal mining disaster to date, the Monongah Mining disaster of Monongah, West Virginia in 1907. The disaster was caused by the ignition of methane gas (also called ""firedamp""), which in"
"electric lights. Miners have traditionally referred to the various gases encountered during mining as damps, from the Middle Low German word ""dampf"" (meaning ""vapour""). Damps are variable mixtures and are historic terms. Before the invention of safety lamps, miners used candles with open flames. This gave rise to frequent explosions. For example, at one colliery (Killingworth) in the north east of England, 10 miners were killed in 1806, 12 in 1809. In 1812, 90 men and boys were suffocated or burnt to death in the Felling Pit near Gateshead and 22 in the following year. When they came into regular"
"Lamps were equipped with a metal gauge to measure the height of the flame. Miners could place the safety lamp close to the ground to detect gases, such as carbon dioxide, that are denser than air and so could collect in depressions in the mine; if the mine air was oxygen-poor (asphyxiant gas), the lamp flame would be extinguished (""black damp"" or ""chokedamp""). A methane-air flame is extinguished at about 17% oxygen content (which will still support life), so the lamp gave an early indication of an unhealthy atmosphere, allowing the miners to get out before they died of asphyxiation."
"Methanometer A methanometer is an instrument used to measure methane gas in the air of a mine. The Mine Safety Appliances Company Ltd. manufactured the first type - W8 Methanometer around 1950 and it was approved for use by the Ventilation Regulations of 1947. The Methanometer could be powered by an Edison battery cap lamp and it could be carried on a miner's belt with other tools. Methane is the main gas present in firedamp. It is highly explosive and had previously been detected by the blue halo effect it gave to the flame of a safety lamp. By 1983,"
"limit, MAPP gas is immediately dangerous to life and health. MAPP gas ""MAPP gas"" is a trademarked name, belonging to The Linde Group, and previously belonging to the Dow Chemical Company, for a fuel gas based on a stabilized mixture of methylacetylene (propyne) and propadiene. The name comes from the original chemical composition, methylacetylene-propadiene propane. ""MAPP gas"" is also widely used as a generic name for UN 1060 stabilised methylacetylene-propadiene (unstabilised methylacetylene-propadiene is known as MAPD). MAPP gas is widely regarded as a safer and easier-to-use substitute for acetylene. In early 2008, true MAPP gas production ended in North America"
"frothing at the mouth, suggests asphyxiation by the predominant afterdamp gas, being carbon dioxide. The afterdamp gas carbon monoxide which presented such a problem for the recovery teams must also have contributed to death through poisoning. It was not then fully appreciated that only small quantities of carbon monoxide or white damp could be fatal”. Rescuers entering the mine after the explosion found themselves suffocating on the afterdamp gas and had to return to the surface, often unconscious, carried by other rescuers; however, the determination was such to find the bodies, and to find any survivors, that the rescuers –"