Due to its explosive properties, methane gas is one of the most important safety concerns for the underground coal miner. Ventilation is typically used to dilute and render harmless dangerous accumulations of methane gas. However, the variability of gas emissions can complicate their control. Variable geologic conditions and gas reservoir parameters, combined with changes in mine design such as larger dimension longwall panels and higher productivity mining equipment, contribute to increased methane emission rates. The ability to predict or anticipate these variations allows the mine operator to address increased emissions in advance of mining. To that end, NIOSH research is addressing:
the effectiveness of a mine's ventilation on diluting methane gas levels on the longwall face and in bleeder entries
the impacts of methane drainage on gas levels measured underground
the challenges of using belt air to ventilate active production faces
flame propagation in large volumes of non-uniformly mixed methane
the effects of non-uniform zones of coal and rock dust along an entry
the effects of coal dust on the ribs/roof compared to floor dust, and
the amount of rock dust necessary to inert typical mine size dust for both high and low volatile coals
NIOSH Projects and Activities
Project
Objective
Mine Explosion Prevention
Prevent and mitigate gas and dust explosions; educate mining personnel on explosion hazard recognition and prevention
Reservoir and Neurosimulation-based Control of Methane
Develop predictive models, simulation tools, and guidelines to predict methane emissions in longwall gobs
Control and Monitoring of Methane in Coal Mines
Determine air flow patterns and movements at the longwall bleeder/gob interface, along with methane air movements at longwall tailgate intersections. Develop effective strategies for the ventilation of larger longwall gob panels along with the monitoring of methane and airflow to assess ventilation effectiveness on continuous miner faces
Analysis of Belt Air Ventilation in Coal Mines
Develop guidelines to help mine operators using belt air to reduce leakage
Contracts and Grants
Title
Contractor
Objective
Remote Methane Sensors (200-2008-24373c)
Ion Optics, Inc.
Integrate a micro electro mechanical system into specialized electronics to measure methane in underground coal mines
The Role of Gas Desorption in the Energetic Failure of Coal (200-2008-25702)
The Pennsylvania State University
Evaluate the role of gas desorbing on the failure of coal and the resultant influence on dynamic failures
Coal Dust Particle Size Survey of U.S. Mines Sapko-MJ; Cashdollar-KL; Green-GM; Verakis-HC | Proceedings of the Sixth International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions (Halifax, NS, Canada, Aug 27 - Sept 1, 2006). Halifax, Canada: Dalhousie University, 2006 Aug; 2:676-682
Effect of Scrubber Operation on Airflow and Methane Patterns at the Mining Face Taylor-CD; Chilton-JE; Hall-E; Timko-RJ | Proceedings of the 11th U.S./North American Mine Ventilation Symposium, University Park, Pennsylvania, June 5-7, 2006. Mutmansky JM, Ramani RV. eds., London, U.K.: Taylor & Francis Group, 2006 Jun; :393-399
Explosion Effects on Mine Ventilation Stoppings Weiss-ES; Cashdollar-KL; Harteis-SP; Shemon-GJ; Beiter-DA; Urosek-JE | Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2009-102, Report of Investigations 9676, 2008 Nov; :1-105
Guidelines for the Prediction and Control of Methane Emissions on Longwalls Schatzel-SJ; Karacan-CÖ; Krog-RB; Esterhuizen-GS; Goodman-GV | Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2008-114, Information Circular 9502, 2008 Mar; :1-83