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| Mapping debris from a partially destroyed stopping |
Background
Although much progress has been made in preventing disasters in mines, explosions still occur, sometimes producing multiple fatalities. There were serious underground coal mine explosions in 2000 in Utah (2 fatalities and 8 injuries), in 2001 in Alabama (13 fatalities and 3 injuries), and in 2003 in West Virginia (3 fatalities and 3 injuries). These events show that the mine explosion problem has not yet been solved.
Underground explosions can be prevented by minimizing methane concentrations through ventilation and methane drainage, by adding sufficient rock dust to stabilize coal dust, and by eliminating ignition sources.
A handheld coal dust explosibility meter (CDEM) is being developed as a more rapid and objective method to verify the rock dust content of coal and rock dust mixtures. Measurements are based on optical reflectivity for rapid in situ determination. Several commercial prototypes have been built, and in-mine evaluations by the Mine Safety and Health Administration (MSHA), the United Mine Workers of America, and various mine operators will continue through 2006.
Explosion effects can be mitigated by (1) the use of passive and active barriers to suppress explosions and (2) the use of high-strength seals to prevent the propagation of gob explosions into working areas of the mine. Research on the causes and mechanisms of gas and dust explosions, as well as on the use of passive and active barriers, will be conducted at the Lake Lynn Experimental Mine as a basis for developing techniques and strategies for explosion prevention, suppression, and mitigation in underground mines and surface facilities.
Potential Outcome
This research will reduce the likelihood of explosions in coal mines by providing the following:
- Recommendations on best practices to prevent and/or mitigate explosions in the mining industry by 2007.
- Improvements in the knowledge base of mining personnel regarding the recognition and prevention of explosions through presentations and videos to the mining industry, including training courses at MSHA’s National Mine Health and Safety Academy during 2006-2007.
- Recommendations for improved forensic accident investigation procedures for MSHA through discussions with and briefing reports to MSHA and through joint publications with MSHA (to be completed in 2006).
- The widespread use of the CDEM by the mining industry will improve management of day-to-day rock-dusting operations. This will help the operator quickly identify accumulations of combustible coal dust and reduce the risk of catastrophic coal dust explosions.