Results 21 - 30 of 348

• Simulation of Spontaneous Heating in Longwall Gob Area with a Bleederless Ventilation System
  8/1/2008 - Peer reviewed journal articles
  To provide insights for the optimization of bleederless ventilation systems for U.S. underground coal mines, a computational fluid dynamics study was conducted to model spontaneous heating in longwall gob areas using a bleederless ventilation system.
• A Gas Pressure-Based Drift Round Blast Design Methodology
  6/1/2008 - Conference papers
  The paper provides: (a) a description of the gas pressure-based design approach to blasting, (b) a simple technique for estimating the damage radius of the buffer row of holes, and (c) a discussion of smoothwall design for the contour row of holes.
• The Borehole Monitoring Experiment: Field Measurements of Reservoir Conditions and Responses in Longwall Panel Overburden During Active Mining
  6/1/2008 - Conference papers
  This paper describes the results of a NIOSH borehole monitoring experiment (BME) on an active longwall panel.
• Effects of Ventilation and Gob Characteristics on Spontaneous Heating in Longwall Gob Areas
  6/1/2008 - Conference papers
  The results of field tests to understand how ventilation and gob characteristics affect the spontaneous heating process causing spontaneous combustion fires in longwall or worked-out gob areas are presented.
• Computational Fluid Dynamics Modeling of Spontaneous Heating in Longwall Gob Areas
  12/1/2007 - Peer reviewed journal articles
  Computational Fluid Dynamics simulations were conducted to investigate the spontaneous heating of coals in longwall gob areas with different apparent activation energies and reaction surface areas. The results are reported in this paper.
• Methods for Controlling Explosion Risk at Coal Mine Working Faces
  9/1/2007 - Conference papers
  This paper reviews how simultaneous application of three basic elements reduces the methane explosion hazard at coal mine working faces: (1) adequate ventilation, (2) regular monitoring of gas concentrations, and (3) elimination of ignition sources.
• Case History of the Response of a Longwall Entry Subjected to Concentrated Horizontal Stress
  2/1/2007 - Peer reviewed journal articles
  A study of ground behavior, reinforcement performance and stress redistribution looked at a longwall tailgate under severe horizontal stress. Comparison to field results showed that a FLAC-2D model captured the significant roof and support behavior.
• Prediction of Longwall Methane Emissions and the Associated Consequences of Increasing Longwall Face Lengths: A Case Study in the Pittsburgh Coalbed
  6/1/2006 - Conference papers
  NIOSH conducted a study with the goal of characterizing methane emissions from increasing face lengths in the Pittsburgh Coalbed and providing a method of predicting emissions increases from longer faces and of planning for more methane control.
• Predicting Methane Emissions from Longer Longwall Faces by Analysis of Emission Contributors
  6/1/2006 - Conference papers
  NIOSH conducted a longwall methane emission and mining time study at a Pittsburgh Coalbed mine to predict emissions from a longer face, and developed and applied mathematical formulas and constants to characterize four emission contributors.
• Ground Control Design for Highwall Mining
  2/1/2005 - Conference papers
  Highwall stability remains a major concern during highwall mining. Geologic structure (hillseams) and pillar stability are the two major factors affecting highwall stability.