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Results 201 - 210 of 255
The face ventilation measurement method developed by the Bureau of Mines involves releasing a small volume of tracer gas (SF6) on the off-curtain side of the working face at the start of the mining cycle.
The Bureau of Mines has designed and put into operation a fail-safe control system for use in underground coal mines equipped with methane drainage pipelines. This control system can detect certain unsafe conditions and respond by automatically shutting...
The use of vertical surface degasification boreholes with bleeder systems and the use of a timbered bleeder system to degasify gob areas were studied by the Bureau of Mines. This report describes three gob degasification studies conducted in the Pittsbu...
1/1/1980 - Information CircularsReviews underground methane drainage programs being conducted in various coalbeds. Equipment used in drainage programs such as drills, underground pipelines, and methane monitoring systems is described.
Drainage of Methane From the Overlying Pocahontas No. 4 Coalbed From Workings in the Pocahontas No. 3 CoalbedThe Bureau of Mines conducted an experimental degasification project in Island Creek Coal Company Virginia Pocahontas No. 5 Mine. Methane from the overlying Pocahontas No. 4 Coalbed was entering mine workings in the Pocahontas No. 3 Coalbed through frac...
The Bureau of Mines developed data on the methane content of the Hartshorne coalbed, Haskell and Le Flore Counties, Oklahoma. The methane content is calculated to be between 1.1 and 1.5 trillion cubic feet. Methane increases with depth, but the rate of ...
Geology, Mining, and Methane Content of the Freeport and Kittanning Coalbeds in Indiana and Surrounding Counties, Pa.This study covers 25 underground mines that were active in the Upper and Lower Freeport and Lower Kittanning coalbeds in 1976. The coal ranges from low to medium volatile in rank.
Because of the high number of accidental methane gas ignitions in metal and nonmetal mines, the Bureau of Mines searched for a simple guideline that would allow mine personnel to evaluate the methane hazard in a given mine.
1/1/1978 - Reports of InvestigationsThe methane gas emitted from coal samples collected from the conveyor belts dumping into silos was measured. Approximately 50 pct of the total gas desorbed into a sealed can within 1 week was released during the first 24 hours. No simple correlation bet...
1/1/1978 - Reports of InvestigationsThe Bureau of Mines examined the wellbore of a vertical gas drainage well in the Mary Lee coalbed to determine the results of specific completion procedures in coal. A jet-slotting tool was used to cut four vertical slots through the casing about 1 ft b...