Back to The MINER Act of 2006 and Related NIOSH Activities

Overview

Mine ventilation seals are commonly used to isolate worked-out sections of a mine from the general mine ventilation atmosphere. Over the years, many thousands of seals have been erected in underground coal mines in this country. Seals, along with generalized rock dusting, constitute the dominant defense against underground coal mine explosions. Without reliable and durable seal designs, a great number of miners’ lives could be in jeopardy. A number of recent explosions in the U.S. underground coal mining industry have resulted in the loss of many lives, suggesting that currently accepted seal construction and design methodologies are inadequate.

NIOSH research will evaluate the factors impacting the strength, integrity, and durability of coal mine seals and bulkheads. Comparisons to construction designs used in Australia, Europe, and South Africa will be investigated. This work will improve the monitoring of gob atmospheres to reduce the likelihood that an explosive methane/air gas mixture accumulates behind the seal line. Other work will examine effective ways to prevent underground explosions. This includes fundamental research into the combustion of large volumes of non-uniformly mixed methane bodies, which may present a different risk than the typical face ignition. Also of interest is the adequacy of the 65% rock dust requirement for mine intakes, since the regulation was based on the average size of coal dust found in intakes during the 1920s. Recent analyses of mine dust samples have shown that the coal dust in main mine intakes is significantly finer in size than the regulations assume.

NIOSH Projects and Activities

• Prevention and Mitigation of Mine Inundations
• Mine Explosion Prevention
• Explosion Pressure Design Criteria for New Seals in U.S. Coal Mines
• Evaluation of Mine Seals

References