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Coal Dust Explosibility and Particle-Size Distribution.

PB94173325

Publication Date	1994
Personal Author	Chaiken, R. F.
Page Count	18
Abstract	An absorption/desorption model of particle reactivity was employed to describe the observed relationship between two apparently diverse phenomena which have been the subject of considerable study at the U.S. Bureau of Mines, viz. (1) coal/rock dust relfectance and (2) coal/rock dust explosibility. A mean particle size parameter, appropriate to the explosion extinction process, is derived, and then taken as appropriate to describing optical reflectance. The derived form-to-function relationships for the two processes, when compared with experimental data, suggest that a problem exists with previously derived theory relating optical reflectance to rock dust concentration. A reexamination of that theory leads to a new theoretical expression, changed by a factor of two, for the variation of rock dust concentration with reflectance which is in quite good agreement with experimental results. The current work offers justification for measuring and establishing rock dust requirements for specific coal dust size distribution(s) found in the mine-distributions which undoubtedly depend on the mining method and the type of coalbed.
Keywords	Coal dust Dust explosions Particle size Underground explosions Autoignition Reaction kinetics Size distribution Reflectance Coal mines Mining engineering Mathematical models
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 79E - Detonations, Explosion Effects, & Ballistics
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center.
Supplemental Notes	See also PB-274 223.
Document Type	Technical Report
Title Note	Rept. of investigations/1994.
NTIS Issue Number	199417

Coal Dust Explosibility and Particle-Size Distribution.

Coal Dust Explosibility and Particle-Size Distribution.
PB94173325

Publication Date	1994
Personal Author	Chaiken, R. F.
Page Count	18
Abstract	An absorption/desorption model of particle reactivity was employed to describe the observed relationship between two apparently diverse phenomena which have been the subject of considerable study at the U.S. Bureau of Mines, viz. (1) coal/rock dust relfectance and (2) coal/rock dust explosibility. A mean particle size parameter, appropriate to the explosion extinction process, is derived, and then taken as appropriate to describing optical reflectance. The derived form-to-function relationships for the two processes, when compared with experimental data, suggest that a problem exists with previously derived theory relating optical reflectance to rock dust concentration. A reexamination of that theory leads to a new theoretical expression, changed by a factor of two, for the variation of rock dust concentration with reflectance which is in quite good agreement with experimental results. The current work offers justification for measuring and establishing rock dust requirements for specific coal dust size distribution(s) found in the mine-distributions which undoubtedly depend on the mining method and the type of coalbed.
Keywords	Coal dust Dust explosions Particle size Underground explosions Autoignition Reaction kinetics Size distribution Reflectance Coal mines Mining engineering Mathematical models
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 79E - Detonations, Explosion Effects, & Ballistics
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center.
Supplemental Notes	See also PB-274 223.
Document Type	Technical Report
Title Note	Rept. of investigations/1994.
NTIS Issue Number	199417