Results 171 - 180 of 270

• Assessment of Methane Hazards in an Anomalous Zone of a Gulf Coast Salt Dome
  1/1/1984 - Reports of Investigations
  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...
• A Short-Range Locator System for Detecting Trapped Miners
  1/1/1984 - Reports of Investigations
  A short-range locator system capable of locating trapped miners has been devised. The system consists of a light-weight, low-power radio transmitter incorporated into a miners cap lamp battery and a directional receiver carried by rescuers.
• Use of a Sodium Silicate Gel Grout for Plugging Horizontal Methane-Drainage Holes
  1/1/1984 - Reports of Investigations
  Methane-drainage holes must be completely filled by grout before mining to prevent the emission of large quantities of gas during mine-through, which would constitute an explosion hazard. In November 1980, seven horizontal holes at the multipurpose bore...
• Influence of Overlying Strata on Methane Emissions in a Northern West Virginia Coal Mine
  1/1/1984 - Reports of Investigations
  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...
• Vertical Magnetic Noise in the Voice Frequency Band Within and Above Coal Mines
  12/1/1983 - Reports of Investigations
  Information on vertical magnetic noise in the voice frequency band, both within and above coal mines, is needed for the evaluation of through-the-earth baseband electromagnetic communications at mines where horizontal loop antennas are used. This report...
• Problems Facing Coal Mining and Gas Production in the Hartshorne Coalbeds of the Western Arkoma Basin, OK
  12/1/1983 - Reports of Investigations
  Major problems facing the development of coal and gas resources of the Hartshorne Coalbeds include the complex distribution of minable and unminable coal, high methane content and bed pressure, faulting, variations in degree of dip, presence of natural ...
• Above-the-Earth Field Contours for a Dipole Buried in a Homogeneous Half-Space
  1/1/1983 - Reports of Investigations
  An essential element of the USBM electromagnetic location and communication system for trapped miners is knowledge of the surface and above-surface electromagnetic fields created by an underground transmitter.
• Control of Longwall Gob Gas With Cross-Measure Boreholes (Upper Kittanning Coalbed)
  1/1/1983 - Reports of Investigations
  The cross-measure borehole technique is being studied as an alternative to the use of surface gob boreholes as a means of controlling methane in gobs during longwall mining. Small-diameter holes are drilled from underground locations into strata overlyi...
• Water Infusion - An Effective and Economical Longwall Dust Control
  1/1/1983 - Reports of Investigations
  In Europe, water infusion is used widely to reduce generation of respirable dust during mining. Its use in the United States is limited to a few plow operations in the Pocahontas No. 3 Coalbed. This Bureau of Mines report describes the technology for in...
• Sulfur Hexafluoride as a Mine Ventilation Research Tool - Recent Field Applications
  12/1/1982 - Reports of Investigations
  Sulfur hexafluoride (SF6) is an odorless, colorless, nontoxic gas that has found acceptance as a tracer gas in research on ventilation patterns, measurement of air leak rates, respirable dust reductions due to bagging hood modifications, and the study o...