Results 251 - 260 of 270

• 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.
• Bleeder System in Virgin Area in a Pittsburgh Coalbed Mine
  1/1/1973 - Reports of Investigations
  Air quantity-pressure and methane concentration surveys were conducted in accessible portions of an area being pillared in a Pittsburgh coalbed mine in West Virginia.
• Degasification of Virgin Pittsburgh Coalbed through a Large Borehole
  1/1/1973 - Reports of Investigations
  The Bureau of Mines is in the process of degasifying a virgin area in northern West Virginia from the base of an 839-foot-deep vertical borehole.
• 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.
• The Composition of Coalbed Gas
  1/1/1973 - Reports of Investigations
  Samples of gas were obtained directly from the coalbed during drilling of horizontal and vertical boreholes in six different formations. The samples were analyzed by gas chromatography.
• An In-Situ Diffusion Parameter for the Pittsburgh and Pocahontas No. 3 Coalbeds
  1/1/1972 - Reports of Investigations
  In this report the importance of diffusion in controlling the emission of methane in mines is examined. An in situ diffusion parameter is defined and calculated for a hypothetical unfractured lump of coal in the Pittsburgh and Pocahontas No. 3 Coalbeds....
• 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 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...