Results 131 - 140 of 149

• Low-Temperature Evolution of Hydrocarbon Gases From Coal
  1/1/1974 - Reports of Investigations
  Although it is generally believed that coal formation occurred at temperatures below 200 deg c, most experimental work on gas formation from coal has been performed at temperatures between 200 deg and 1,000 deg C. The objective of this Bureau of Mines e...
• Methane Emission from U.S. Coal Mines in 1973, A Survey: A Supplement to IC 8558
  1/1/1974 - Information Circulars
  This Bureau of Mines survey of methane emissions indicates that total daily emissions have declined from 227 mm ft3 in 1971 to 214.7 mm ft3 in 1973. The highest average daily emissions in million cubic feet per day are detailed by state.
• Methane Control by Isolation of a Major Coal Panel - Pittsburgh Coalbed
  1/1/1973 - Reports of Investigations
  As one of its projects for degasification of major panels of coal prior to mining within them, the Bureau of Mines conducted methane emission studies during development of a set of three headings 1,800 feet in a major coal panel (2,700 by 3,500 feet) wh...
• Geologic Factors Causing Roof Instability and Methane Emission Problems: The Lower Kittanning Coalbed, Cambria County, Pa
  1/1/1973 - Reports of Investigations
  A geologic study of Mines 32 and 33 in Cambria County, Pennsylvania, was conducted as part of a methane control research program.
• The Direct Method of Determining Methane Content of Coalbeds for Ventilation Design
  1/1/1973 - Reports of Investigations
  The applicability of the "direct method" for determining the methane content of virgin coalbeds was tested. Preliminary results indicate that the direct method, when applied to exploration cores, can be successfully used to estimate coalbed gas content ...
• Gases Desorbed From Five Coals of Low Gas Content
  1/1/1973 - Reports of Investigations
  To determine if coals from mines which had no history of detectable gas emission contained adsorbed methane, samples of coal at the shaft bottom and at an active face were obtained and placed in sealed metal cylinders.
• Methane Diffusion Parameters for Sized Coal Particles: A Measuring Apparatus and Some Preliminary Results
  1/1/1972 - Reports of Investigations
  A sorption apparatus for measuring the equilibrium sorption isotherm and the rate of diffusion of methane from fine-sized coal was designed and constructed. Preliminary work that used Pittsburgh and Pocahontas No. 3 Coal shows that the diffusion coeffic...
• Methane Emission from U.S. Coal Mines, A Survey
  1/1/1972 - Information Circulars
  This survey was conducted to determine the magnitude of the methane emission and control problem in U.S. bituminous coal mines. The resultant data indicate that the emission rate for any given coalbed depends primarily on the coal production rate and on...
• Methane and Dust Control by Water Infusion: Pittsburgh Coalbed (Fairview, W. Va.)
  1/1/1972 - Reports of Investigations
  The effect of water infusion on the flow of methane and on the production of dust was investigated at an active face in the Pittsburgh coalbed. The average total flow of methane at the face decreased by approximately 79 percent, whereas the flow from th...
• Effect of a Surface Borehole on Longwall Gob Degasification (Pocahontas No. 3 Coalbed)
  1/1/1972 - Reports of Investigations
  The use of a partially slotted 6.5-Inch-inside-diameter vertical pipe to remove methane from a longwall gob area at a depth of 2,260 feet in the Pocahontas No. 3 Coalbed was investigated. The value of gas removed by such a pipe under free-flow condition...