Mining Program Area: Explosion Prevention
The purpose of the explosion prevention program is to:
- eliminate explosions in underground coal mines. Through this research, OMSHR will determine the appropriate sampling interval to detect the hazard of a propagating explosion based on how far an explosion can travel through an inert length of an entry;
- assess the current band sampling method’s ability to produce a representative sample of coal/rock dust that contributes to an explosion;
- determine if floor dust is currently over-sampled, and therefore underestimating the hazard of coal dust on the top most layers of dust on a mine floor, roof, and ribs;
- evaluate if the current practice of not sampling the inaccessible side of a belt entry results in an underestimation of the explosion hazard;
- determine if variations in the surface moisture present in mine dust presents, over time, a potential for underestimating the explosion hazard based on the current collection and analysis method;
- conclude if the current practice analyzing the < 20 mesh dust results is an underestimation of the potential dust explosion hazard compared to a < 60 mesh cut used in other countries;
- quantify the effect that variable mineral composition and particle size distribution in currently compliant rock dust has on its capacity to inert coal dust;
- identify relationships between the methods and frequency of rock dust application and the ability to maintain inert dust concentrations in mines;
- andassess the use of rock dust barriers as supplemental protection in belt entries.
This work affects mine worker health and safety by eliminating coal dust explosions in underground coal mines through improved methodologies for identifying and mitigating explosible accumulations of coal dust.
We are investigating aspects of rock dusting and dust sampling that have existed for several decades. Since the adoption of these explosion prevention requirements, mining methods have developed and changed considerably, resulting in finer coal dust being generated by the mining process. Consequently, these changes may require a different sample collection method to adequately determine the explosion hazards.
Significant milestones on these projects and contracts include:
- a fundamental scientific understanding of critical dust sampling issues that identify potentially dangerous accumulations of hazardous mixtures of coal and rock dust,
- engineering procedures and analysis protocols for collecting representative samples to identify dangerous accumulations of explosible dust mixtures,
- a characterization of the influence rock dust size and composition has on its ability to effectively inert coal dust, and
- technology transfers to inform the Mine Safety and Health Administration (MSHA) and the mining community about proper dust sampling and application techniques.