Dust Explosion Research Development for Coal Mining Safety Issues

Jiaojun Jiang, Xiaodan Gao, M. Sam Mannan*

Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA

Abstract

On April 5, 2010, a massive coal dust explosion occurred at the Upper Big Branch Mine-South.  Twenty-nine people were killed in the incident. It was the largest coal mining disaster in the United States since 1970.

Other than the United States, countries like China and India – who are the other two largest coal producers and consumers in the world – also have similar catastrophic incidents. Statistics in recent years show that the number of incidents, death tolls and fatality rates per million tons are still high, especially in China and India. These incidents have grabbed the attention of the public and the media only for a short period after occurring. Unfortunately, this type of attention does not help to prevent the next tragedy. The much more important thing is to learn the lessons from these tragedies by doing a complete study of the underlying hazards in the coal mining process. Coal mining incidents are generally caused by explosion, fire, haulage, ground fall/bump, and inundation. With regard to explosion, a lot of attention has been paid only to pure dust or pure gas explosions during the past few decades. However, several disasters with massive loss of lives and properties were caused by the hybrid mixture explosions with methane and coal dust together. Research on hybrid mixture explosions rather than pure gas or dust explosions can rarely be found. 

This paper discusses the present dust explosion research developments in the Mary Kay O’Connor Process Safety Center and how to apply the research methodologies to coal mining safety issues. Specifically, studies on hybrid mixtures show that the presence of a small amount of flammable gas can significantly increase the explosion index of dust as well as the maximum explosion pressure. Furthermore, the lower flammable limits of the hybrid mixture are lower than each components’. The research methodology and results can be used for risk assessment and prevention in the coal mining industry.

Keywords:

Coal Explosion, Dust Explosion, Hybrid Mixture Explosion