Monitoring and Sampling Approaches to Assess Underground Coal Mine Dust Exposures (2018) / Chapter Skim
Currently Skimming:
2 Effects of Rock Dust Applications on Coal Mine Dust Measurements
2 Effects of Rock Dust Applications on Coal Mine Dust Measurements
Pages 29-40
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 29... ...
(2016) and the references cited therein provide ample evidence that Coal dust represents an explosion hazard in underground coal mines, which has been demonstrated collectively by experimental work and documentation of coal mine explosion disasters, and Coal dust explosion hazards often can be mitigated effectively through a proper rock dusting program.
|
From page 30... ...
and available for entrainment in working environments in typical rock dusts currently used in the United States. This chapter discusses the current technology and its application for rock dusting, composition and particle size distribution of available rock dusts, and effect of rock-dusting practices on measurements of respirable coal mine dust (RCMD)
|
From page 31... ...
(2010) recommended: "In view of these results, there is a need to re-examine the particle size specifications for rock dusts and determine the material specific requirements relevant to the incombustible content needed to prevent explosion propagation." The authors also recommended that, "In view of current results from the NIOSH coal dust particle size survey in US mines and preliminary size analyses of rock dusts, the effect of rock dust particle size in preventing coal flame propagation should be re-examined through large-scale explosion tests." Since the nature of coal dust explosions has been researched extensively, much of the current research focuses on rock dust composition.
|
From page 32... ...
During the process of developing new rock dust technologies, the particle size distribution of feed rock dust has come under much scrutiny. Determination of the optimum rock dust particle size distribution is necessary to develop optimized solutions that mitigate the possibility of massive coal dust explosions and protect miners from respiratory hazards associated with RCMD exposure.
|
From page 33... ...
Data presented in Figure 2-2 suggest that coal mines are susceptible to explosion propagation even at 80 percent incombustible content of coal mine dust, given high content of minus 200 mesh coal dust material. It also suggests that smaller particle size distributions in the rock dust applied may provide a better heat sink and allow for the lower incombustible contents required to prevent propagation.
|
From page 34... ...
The authors recommend a particle size distribution with 95 percent of material finer than 200 mesh for mitigating the propagation of coal mine dust explosions. In addition, the authors describe a way of correlating specific surface area of rock dust particles to performance.
|
From page 35... ...
It is apparent that respirable particles are present in rock dust products that are available for use in underground coal mines. A presentation provided by NIOSH, dated June 2, 2016, describes some of the ways that rock-dusting practices affect CPDM measurements and provides recommendations on how to mitigate RCMD exposure from rock dusting (NIOSH, 2016)
|
From page 36... ...
One concern regarding those results is that rock dusting during mine operations is not advisable because it can elevate RCMD concentrations. The other concern is that treated rock dust is more susceptible to entrainment for the very same reasons that it is probably more effective at long-term protection from coal mine dust explosions.
|
From page 37... ...
CONCLUSIONS 1. Rock dusting is a proven and necessary technique for mitigating coal mine dust explosion hazards.
|
From page 38... ...
5. It is evident that more comprehensive research is needed to identify optimum rock dust par ticle size distributions for applications in underground mines with different particle sizes of coal mine dust.
|
From page 39... ...
2010. Rock dusting considera tions in underground coal mines.
|
From page 40... ...
2001. Passive and Triggered Explosion Barriers in Underground Coal Mines – A Literature Review of Recent Research.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.