PHOTOGRAPH BY EMRAH GUREL, ASSOCIATED PRESS
Published May 15, 2014
Two days after a coal mine fire killed at least 283 workers in western Turkey, mourning was mixed with angry protests sparked by the perception that the nation's increasing desire for coal energy had compromised mining safety. (See: "Pictures: Mine Blast in Turkey Kills More Than 200.")
Violent clashes between rioters and police in the capital city of Ankara signaled that some were using the mining deaths to revive long-held grievances against the government of Prime Minister Recep Tayyip Erdogan. Other critics claimed that Tuesday's deadly blast symbolized how more aggressive drilling for coal—encouraged by Erdogan's government—had made mining more perilous for workers.
In particular, the deaths at the mine in Soma, a town about 300 miles (483 kilometers) southwest of Istanbul, raise questions about whether Turkey's government and its mining companies have done enough to limit extremely flammable methane gas and coal dust at a time when the nation is boosting its commitment to coal. (See: "Powering Our Urban Future: Spotlight on Turkey.")
The owner of the mine, Soma Komur Isletmeleri A.S., has said that it upheld the "highest safety measures and constant controls." Turkish officials said the mine had been inspected as recently as March, with no problems reported.
Officials blamed a transformer explosion for the blast and subsequent fire, which was still burning Thursday. However, an electrical glitch on its own would not necessarily cause an accident of the magnitude seen at the Soma mine, said an official with the Mining Safety and Health Administration in the United States, where regulators have managed to dramatically reduce—but not eliminate—worker casualties in mines.
Coal mine explosions and fires typically happen when either methane or coal dust present in the mine meets with a spark and ignites.
"There is probably more involved" in the Turkey explosion than just a blown transformer, said the U.S. official, who was not authorized to speak publicly. "They are electrical devices, and they can fail. But usually when they fail, it's a localized thing, within a few hundred feet in the worst case."
Turkey's Increasing Push for Coal
Yücel Demiral, an occupational health specialist based in western Turkey who co-authored a paper released last year about the country's coal mine safety, said that although there is no confirmation about the role of coal dust or methane in the Soma tragedy, the privatization of Turkey's coal industry in recent years has led to new safety questions.
During the past decade, ownership of mines in Soma has transitioned from the state to private companies, Demiral said. The private owners have been "more profit-oriented," he said, cutting worker salaries and digging deeper than before into the coal seams in Soma.
Turkey's energy ministry notes that coal prospecting has increased fivefold in the past nine years, resulting in the discovery of new lignite reserves that have boosted the country's total stores by more than 50 percent. (See related story: "Germany Plans to Raze Towns for Brown Coal and Cheap Energy.")
"Normally in this region, we don't expect methane gas" as part of the lignite mining that takes place in Soma, Demiral said. However, as companies dig deeper, there is a higher risk of meeting dangerous concentrations of methane. Even so, he said, "there is no knowledge or expertise" in Turkish mining operations "regarding the methane issues."
Demiral said that the same mines, under private ownership, have become four times more profitable than they were under the state, and that companies have taken "shortcuts" when it comes to workers' welfare.
His paper noted that there are only 1,000 government labor inspectors in a country of 81 million, and that supervisory authorities sometimes contradict each other. "This lack of cooperation may mean that some mines are audited a few days apart by the different institutions," the paper said, "while other mines are audited after a long time, or not audited at all."
Coal accounts for about 28 percent of Turkey's electricity generation, a figure the government is trying to increase. (The United States, by comparison, depends on coal for 37 percent of its electricity generation, but increasingly is moving toward natural gas.) Most of Turkey's coal reserves are lignite, or brown coal, the low-quality fuel used mainly to generate electricity. Estimates vary about the number of deaths attributed to coal mining in Turkey, but one state-run agency reported that 3,000 workers had died in mine accidents since 1941.
Despite the dangers and pollution associated with coal, there is pressure in Turkey to meet growing energy demand by producing more coal domestically to avoid pricier natural gas imports in the absence of its own shale resources.
"Coal is essential as an energy source," the Turkish energy ministry says in recently updated copy on its website. "In Turkey, coal is now referred to as the energy source of the future."
Dangers to Workers Worldwide
More than ten million people worldwide are employed producing coal, according to the International Labour Organization. Though fatalities largely have declined during the past decade, thousands of coal workers still die on the job every year.
China's coal industry, in particular, has an "unacceptably high" fatality rate, "particularly due to the number of unregulated small coal mines that have operated in recent years," according to the World Coal Association. Last year more than 1,000 workers died at Chinese coal mines, according to government figures—a rate exponentially higher than that of the United States, but still an improvement from the 7,000 coal worker deaths China saw in 2002.
"Fire and explosion have long been and remain the most common sources of mass fatality incidents in coal mines," noted an Australian report on coal mine worker safety this year. Other hazards include falling rock or earth, flooding, and toxic fumes. Of the ten most recent coal mine accidents listed on China's State Administration of Work Safety site, six involved explosions. (See related story: "Clean Coal Test: Power Plants Prepare to Capture Carbon.")
Lessons From West Virginia
The United States has been able to cut dramatically the number of fatal coal mining accidents in recent years. Deaths have fallen from an average of 150 per year in the 1970s to under 50 over the past decade. But deadly accidents are still happening: Just this week, two workers were killed at West Virginia's Brody No. 1 mine in a rock collapse.
Explosions, though rarer in the United States than they used to be, also remain a potent risk to workers. In 2010, a gas explosion at the Upper Big Branch mine in West Virginia killed 29 people and injured two others. In that accident, according to the state's investigative report, heat from a tool used to cut sandstone ignited methane in the mine, which then ignited coal dust. It was the worst U.S. mining disaster in 40 years.
"Coal dust by itself is just like gunpowder when it gets suspended in the air or when it's collected on the mine floors," says Greg Norman, administrator for the West Virginia Office of Miners' Health Safety and Training. "If you have a methane explosion [that] just kicks up more coal dust, it becomes like a huge bomb."
Norman said that among several measures that can be taken to prevent explosions, spreading rock dust is key. When distributed throughout the mine, rock dust acts as a fire retardant, keeping overall combustibility down. Adequate ventilation to avoid buildup of methane also is crucial.
The techniques are nothing new. "There is a lot of new technology out there now, but the two biggest things to prevent mine explosions are [still] rock dust and ventilation," Norman said, referring to measures that have been in place since the U.S. Mine Health and Safety Act of 1969. (See related story: "New Energy Frontier: Drilling Into Coal for Gas.")
There is little evidence that rock dusting is being used with any regularity in Turkey; a 2009 study of dust in Turkish coal mines makes no mention of the practice. Demiral's paper said of the mining industry, "There is a lack of supervision and auditing, and the conditions are primitive in both public and private enterprises."
In West Virginia, the Upper Big Branch mine's parent company failed to adequately deploy rock dusting and other preventive measures, such as water-spraying equipment and continuous monitoring for methane and coal dust. The company, Massey Energy, was fined more than $10 million for safety violations, and one of its top executives was sentenced to 42 months in prison last year.
It is possible that in Turkey, protests and public anger over the Soma mine tragedy might force leaders to explore regulatory changes. But as the case of Upper Big Branch shows, regulations do not always prevent disaster. (Vote and comment: "What Energy Solution Should We Be Developing Next?")
Demiral expressed little hope that the Soma incident would result in any real explanation of what caused the blast, or any change in regulations by the government. Prime Minister Erdogan's public comments have suggested that he sees such accidents as part of the risk of mining, and the general response from officials has been defensive.
"It's more blaming the victims," Demiral said. "They are ignoring the problem."
I just looked at the 2009 dust study, which mentioned that a lot of the mines are longwall mines rather than the room and pillar approach I described. This alternate mining technique still results in mined out areas that can be isolated from the rest of the mine by air-tight seals at particular tunnels, so my comments still apply.
I strongly second the comments by US mine safety officials. Explosions of this magnitude are very preventable using methods required in the US since 1969. The science and appropriate practices are well established.
Methane outbursts are always possible, in which mining encounters a pocket of methane that rapidly enters the working face. For this to explode, it needs an ignition source and some time to accumulate and spread. Properly designed and maintained mining equipment will not produce electrical sparks (because of the design), though a cutter bit hitting chert or very hard sandstone in the mine roof might produce a spark if such rocks are present. I have heard of pops occurring at the cutting head of a continuous miner machine in US mines.
However, frequent monitoring of gas conditions can warn a miner that dangerous conditions are occurring (there are also automated cut-off switches tied to automatic monitors). This will allow suspension of mining (which could produce sparks) until the methane concentrations can be lowered by ventilation.
The mining should also employ an adequate ventilation system, including temporary curtains hung to bring the air to the working face, that continuously dilutes and flushes out slow methane accumulations. The volume and rate of air circulated should be sufficient to keep methane levels below dangerous limits throughout the active part of the mine. Ventilation plans are a regulatory requirement in the US, subject to approval and enforcement by governmental agencies. This also helps reduce dust-inhalation by the miners as they are to always work on the intake air side of the ventilation instead of the exhaust.
Then most important is adequate rock dusting. A major explosion generally does not get all of its energy from methane in a properly monitored and ventilated mine. When the initial methane explosion occurs, the expanding air of the explosion lifts coal dust off the walls and floor, entraining and mixing it with the air to create an explosive mixture. The heat of the explosion then detonates this mix, which then expands again, entraining more coal dust and propagating the explosion throughout the mine. The coal dust explosion is exothermic, it produces more energy than is needed to initiate it, so it won't stop until the entire dusty mine blows up. If powdered limestone dust has been added on top of the coal dust before any explosion, however, the initial methane explosion cannot propagate. When the first blast of hot air entrains the dust, the blending of limestone with the coal dust quenches the reaction, absorbing more heat than the burning of the coal dust produces. The methane explosion is all you get and that should be a small, localized explosion if adequate ventilation and air monitoring prevent the build up of large areas of methane within the worked areas of the mine.
Another practice, which was not properly followed at the Darby Mine, is to build air-tight walls within the lateral mine tunnels to block off airflow between mined-out areas and those actively mined. During mining, the coal is extracted using a lattice-like pattern of parallel tunnels and connecting cross-cuts, leaving square blocks of un-mined coal between these tunnels and cross-cuts (called pillars) to support the weight of the overlying rock undermined by removal of the mined coal. After mining is completed in an area, these areas should be isolated from the rest of the mine. That way, the ventilation system can keep methane concentrations in control within the active part of the mine and the sealed-off older parts of the mine cannot be a source of methane to the active mine.
One newer practice recommended/required since recent mine accidents is establishment of miner sanctuaries at various places in the mine with bottled air and a means to seal off the location from smokey mine air. It is common for miners who survive the initial blast or other problem to die of carbon monoxide exposure. Such sanctuaries would have to hold adequate air to support the miners long enough for rescue to occur or at least until a borehole can be drilled to the sanctuary to pump in more air. Sanctuaries may also be needed where flooding of a mine is a possibility. All underground miners should know where the sanctuaries are located and they should be moved as needed as the active mine areas progress.
The large number of miners underground in this mine indicate a much less mechanized mine than in the US. The 29 killed in the Darby disaster is more representative of the size of shifts in US mines. Establishing sanctuaries will be more difficult when allowing for the greater number, though the air issue could be handled by pre-drilling a borehole to the established sanctuaries.
ᴊᴜsᴛ ᴀs Sᴛᴇᴘʜᴇɴ sᴀɪᴅ I'ᴍ sᴛᴀʀᴛʟᴇᴅ ᴛʜᴀᴛ ᴘᴇᴏᴘʟᴇ ᴄᴀɴ ɢᴇᴛ ᴘᴀɪᴅ $8080 ɪɴ ᴏɴᴇ ᴍᴏɴᴛʜ ᴏɴ ᴛʜᴇ ɪɴᴛᴇʀɴᴇᴛ . ᴛʜɪs ᴘᴀɢᴇ
such anger,the corruption is extreme,the criminals are in charge,time for a change,corruption must end for us to live a normal life, yes and it is everywhere,in your town,please report all corruptions,and crimes.
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