Barometric-Induced Gob Breathing: Root Cause, Effect and Recommended Best Practices

Details

• Personal Author:
  Brune, Jürgen F. ; Lolon SA
• Description:
  In underground longwall coal mining, the mined-out areas or gobs frequently contain methane which can form explosive methane-air mixtures. Historically, there have been many events of mine fires and explosions recorded in the United States and other countries that have demonstrated the existence of such explosive mixtures, herein referred to as Explosive Gas Zones (EGZs), inside and around the perimeter of bleeder-ventilated longwall gobs (Loane et al., 1975; Lynn et al., 1986; Elkins, et al., 2001; McKinney et al., 2001; Dziurzynski and Wasilewski, 2012; Brune, 2013). The risk of mine explosions can increase if the EGZs migrate out from the gob into the surrounding mine entries. Several factors can induce EGZs outflowing from the gob, but the most common cause is the fluctuating barometric pressure. Atmospheric pressures change regularly every day but can fluctuate abruptly and become increasingly hazardous in adverse weather conditions. Other sudden pressure changes can result from roof falls, failing ventilation controls and fan outages. Any such fluctuation of mine ventilation pressure will disturb the pressure differential between the gob and the surrounding mine workings and may cause EGZs to outgas from the gob. The correlation between major mine explosions and abrupt barometric pressure changes has been studied and confirmed for explosions in coal mining countries including the United States, South Africa, Australia, and Poland (Hosler, 1948; Boyer, 1964; Kissell et al., 1973; Fauconnier, 1992; Hemp, 1994; Wasilewski, 2014; Belle, 2014; and Lolon, 2017). Disastrous mine explosions appear to happen more frequently during stormy weather, which, in the United States, typically occurs during the late fall and winter seasons. [Description provided by NIOSH]
• Subjects:
  Explosions Occupational Health Safety Ventilation
• Keywords:
  Coal Mines Explosive Gases Longwall Mining Methane Control Seasonal Factors Storms
• Publisher:
  Society for Mining, Metallurgy, and Exploration, Inc.
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-6
• NIOSHTIC Number:
  nn:20068870
• Citation:
  2018 SME Annual Meeting, February 25-28, 2018, Minneapolis, Minnesota, preprint 18-012. Englewood, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2018 Feb; :1-6
• Federal Fiscal Year:
  2018
• Performing Organization:
  Tustees of the Colorado School of Mines
• Peer Reviewed:
  False
• Start Date:
  20140901
• Source Full Name:
  2018 SME Annual Meeting, February 25-28, 2018, Minneapolis, Minnesota, preprint 18-012
• End Date:
  20190831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:71ca6fd57392927406f4c3edfddb1ccf5daa47665b795f2db7d6dfbee6f0c31391edbd8890bc67252139dfd0fa9ec3e52cb931e926f12a5e0d2baffea2bac51a
• Download URL:
  https://stacks.cdc.gov/view/cdc/207437/cdc_207437_DS1.pdf
• File Type:
  [PDF - 896.00 KB ]