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Results 181 - 190 of 255
Research was conducted to determine whether the total elapsed delay time for blasting bituminous coal in underground coal mines could be safely expanded beyond the 500-ms limitation without igniting a methane or methane-coal dust atmosphere.
This report presents a data base of gas content data. The data are presented in tabular form, by coalbed name and state. The components of the total gas content (lost, desorbed, and residual gas) are given. Location (state and county), sample depth, coa...
The goal of this research was to evaluate the integrity of existing shutoff valves and actuators used under high-temperature conditions in the Bureau of Mines' horizontal borehole methane drainage pipeline system and to determine system improvements.
1/1/1985 - Reports of InvestigationsThe cross-measure borehole technique is an effective method of controlling methane liberated by fracturing the roof strata in longwall gobs where overburden is less than 750 ft (229 m). About 71 pct of the methane produced by longwall mining in the Lowe...
1/1/1985 - Reports of InvestigationsThe Bureau of Mines and United States Steel Corp. are conducting a joint project to monitor formation pressures at a large (23-well) coalbed gas drainage field near Oak Grove, Alabama. Three monitor holes were drilled in late 1981, and pressure monitori...
The Bureau of Mines has successfully tested a method to simulate methane (CH4) flows from face areas through the returns of noncoal mines. This technique involves releasing a small quantity of tracer gas at a working area and sampling for that gas downs...
This report considers the results achieved when 80 domal salt samples were tested for gas content by dissolution in a controlled atmosphere chamber.
This Bureau of Mines research study found gas emission rates from an advancing face, and flows and pressure of gas from an exploration drill hole were dependent upon the geology of salt encountered in a domal salt mine. This information suggests a great...
1/1/1984 - Information CircularsA tabulation of methane emissions during 1980 for all United States coal mines with emissions greater than 0.1 MMcfd. The report also compares records of 1975 and 1980 and describes relationships between emissions in 1980 and the Bureau's coalbed gas co...
Since 1970, abnormally high methane emissions have been observed in eastern sections of the Federal No. 2 Mine operating in the Pittsburgh coalbed in northern West Virginia. The nature and volume of these emissions indicate a source other than the coalb...