Results 41 - 44 of 44

• Strength Characteristics and Air-Leakage Determinations for Alternative Mine Seal Designs
  1/1/1993 - Reports of Investigations
  During the normal course of underground coal mining, it sometimes becomes necessary to seal off abandoned areas to eliminate the need to ventilate them. Seals also are used to isolate fire zones or areas susceptible to spontaneous combustion. The object...
• Evaluation of Solid-Block and Cementitious Foam Seals
  1/1/1991 - Reports of Investigations
  The U.S. Bureau of Mines conducted explosion tests on various full- scale cementitious bulkheads used in abandoned mine areas to evaluate the ability of the bulkheads to withstand gas explosion overpressures of 20 psig. Tests were performed on 120-ft2 s...
• Evaluating Ventilation Parameters of Three Coal Mine Gobs
  1/1/1986 - Information Circulars
  The Bureau of Mines used sulfur hexafluoride (sf6) tracer gas to evaluate the effectiveness of gob ventilation and/or sealing practices at three coal mines, each having different problems associated with their mined-out areas.
• Demonstration of Safety Plugging of Oil Wells Penetrating Appalachian Coal Mines
  7/1/1972 - Technical Progress Reports
  An oil well penetrating the Pittsburgh bituminous coalbed in northern West Virginia was plugged and safely mined through 3 months later. Effectiveness of the plugging in preventing reservoir gas from entering the mine through the well hole was verified ...