Dust Explosion Research Development for Coal Mining Safety Issues

摘要

China, U.S. and India are the three largest coal producers and consumers in the world. 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 attracted the attention of the public and the media for only a short period after the occurrence of the incident. 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 from the Mary Kay O'Connor Process Safety Center (MKOPSC) 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 of the components' limits. The research methodology and results can be used for risk assessment and prevention in the coal mining industry.