Although much progress has been made in preventing underground coal mine disasters, ignitions still occur, sometimes producing violent explosions. Examples include serious underground ignitions and explosions in:
July 2000 at the Willow Creek Mine in Utah (2 fatalities and 8 injuries)
September 2001 at Jim Walter Resources No. 5 Mine in Alabama (13 fatalities and 3 injuries)
January 2003 at the McElroy Mine in West Virginia (3 fatalities and 3 injuries)
January 2006 at the Sago Mine in West Virginia (12 fatalities and 1 injury), and
May 2006 at the Darby No. 1 mine in Kentucky (5 fatalities and 1 injury)
Frictional ignitions arising from the striking action of the cutting bit on hard rock have occurred at a rate of about 45 to 80 annually over the past ten years with no apparent upward or downward trend. Safety controls and worker training have succeeded in reducing the number of non-frictional ignitions to about 5 to 15 annually over the same period. These include ignitions caused by other sources such as cutting torches and lightning.
NIOSH research addressing these issues includes the development of standard test methods to evaluate gas/dust ignitability and explosibility. Laboratory research on coal face frictional ignitions includes the measurement of the hot-spot temperatures and heated surface areas necessary to ignite flammable gases, liquids, dusts, and hybrid mixtures. This research will provide guidelines for quickly and accurately identifying factors that affect the severity of an ignition. Research is also being conducted to determine the root causes of flame cutting and welding fires. This work will lead to the development of guidelines for flame cutting and welding in underground coal mines.
NIOSH Projects and Activities
Project
Objective
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
Mine Explosion Prevention
Prevent and mitigate gas and dust explosions; educate mining personnel on explosion hazard recognition and prevention
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
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