PURPOSE:  To reduce hazards in mining through basic and applied research on the prevention and mitigation of gas and dust explosions and the education of mining personnel on explosion hazard recognition and prevention.

RESEARCH SUMMARY:  Much progress has been made in preventing underground coal mine disasters, but explosions still occur, sometimes producing multiple fatalities. In an explosion, all underground miners are at risk. There were serious underground coal mine explosions in July 2000 at the Willow Creek Mine in Utah (2 fatalities and 8 injuries), in September 2001 at Jim Walter Resources No.5 Mine in Alabama (13 fatalities and 3 injuries), in January 2003 at the McElroy Mine in West Virginia (3 fatalities and 3 injuries), in January 2006 at the Sago Mine in West Virginia (12 fatalities and 1 injury), and in May 2006 at the Darby Mine No. 1 in Kentucky (5 fatalities and 1 injury). Explosions are caused by accumulations of flammable gas and/or combustible dust mixed with air in the presence of an ignition source. Research on gas and dust explosions is needed as a basis for the development of techniques and strategies for explosion prevention, suppression, and mitigation.

This project studies explosion propagation and explosion combustion mechanisms through full-scale tests at the Lake Lynn Experimental Mine (LLEM) and through laboratory tests in a 20 liter chamber. The LLEM research includes flame propagation in large volumes of non-uniformly mixed methane, the effects of non-uniform zones of coal and rock dust along an entry, and the effects of coal dust on the ribs/roof compared to floor dust. Researchers will also study the amount of rock dust necessary to inert typical mine size dust for both high and low volatile coals. Basic research on the explosion mechanisms and flame propagation will attempt to reach a more fundamental understanding of mine explosions. In conjunction with these LLEM tests, there is a task to improve the supporting documentation/research used by the Mine Safety and Health Administration (MSHA) in investigating explosion disasters. In a collaborative task with MSHA, an in-situ meter is being developed and field tested. This meter will quickly determine the explosibility and/or the incombustible content of coal and rock dust mixtures in coal mines, thereby improving sample analysis and rock dusting practices.

The results of the research in this new project will be communicated to stakeholders in briefing reports to MSHA, conference papers, and peer-reviewed journal papers. Achievements will include the development of improved forensic procedures for use by MSHA in investigating mine explosion accidents and the development of improved laboratory test methods as consensus standards for the determination of explosibility characteristics. Additional recommendations on the best practices to prevent and/or mitigate explosion hazards are expected. The outcome of this research effort will be a reduction in the risk for gas/dust explosions in the underground workplace through an increased understanding of the causative factors for these events, the development of improved control technologies, and educating the workforce to recognize and prevent explosions.