How Limestone Rock Dust Eliminate Coal Dust Explosions Experimental

How Does Limestone Rock Dust Prevent Coal Dust …

Coal dust explosions in underground coal mines are prevented by generous application of rock dust (usually limestone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents flame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of explosion experiments using various coal dust and limestone rock dust mixes have been carried out at the Lake Lynn Experimental …

How Does Limestone Rock Dust Prevent Coal Dust Explosions ...

Coal dust explosions in underground coal mines are pre­ vented by a generous application of rock dust (usually lime­ stone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents fl ame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of ex­

How does limestone rock dust prevent coal dust …

These dust samples have been analyzed in the laboratory using thermogravimetric analysis (TGA) and solubility to determine how the limestone rock dust behaved during the coal dust/rock dust explosions. The preliminary results are reported in this paper and indicate that the chemistry of limestone plays an important role in its capacity to inhibit coal dust explosions. …

how does limestone rock dust eliminate coal dust ...

Does Line Rock Dust Eliminate Coal Dust Explosions Experimental Introduction - stacks.cdc.gov Other research has shown that the coal or rock dust accumulated on the rib or roof surfaces or other elevated surfaces (overhead dust) is easier to disburse or entrain into the turbulent air created by an explosion shock wave than dust on the mine ...

Effects of rock dusting in preventing and reducing ...

01/06/2017· The anecdote evidence for rock dust to control coal dust explosion is shown in the demonstration tests conducted at the South Africa’s CSIR (Council for Scientific and Industrial Research) Kloppersbos facility (Fig. 4). In the demonstrations, the explosion of one teaspoon of coal dust in a steel tube results in a large fire ball above the tube as shown in the left of figure and a loud noise. When one teaspoon …

Experimental mine and laboratory dust explosion research ...

01/05/2000· In the limestone rock dust inerting tests in the LLEM, the Pittsburgh coal required about 78–80% rock dust or 80–82% total inert content in the coal–rock mixture in order to prevent explosion propagation. The higher volatility gilsonite required about 10% more rock dust than the coal to be inerted. Two theoretical models based on a calculated, adiabatic limit …

Participation of large particles in coal dust explosions ...

01/01/2014· Different sized fractions of coal dust and rock dust were examined for their participation in an explosion. • Large coal dust particles (250–841 μm) did not explode in the 1-m 3 chamber, even when ‘overdriven.’ • Large limestone rock dust particles (250–841 μm) offer almost no protection as an inhibitor in these laboratory tests.

Recent trends in rock dust modifications for improved ...

01/05/2016· Rock dusting has been used for about 100 years by applying the inert rock dust (typically limestone or dolomite) to increase the total incombustible content of admixtures and effectively quench the flame propagation and coal dust explosion by acting as a thermal inhibitor or heat sink (Rice, 1914; Amyotte et al., 1995, Man and Teacoach, 2009, Cashdollar et al., 2010).

Influence of specific surface area on coal dust ...

01/07/2018· The relationship between the explosion inerting effectiveness of rock dusts on coal dusts, as a function of the specific surface area (cm 2 /g) of each component is examined through the use of 20-L explosion chamber testing. More specifically, a linear relationship is demonstrated for the rock dust to coal dust (or incombustible to combustible) content of such …

Coal dust explosions and their prevention

coal dust explosions and to sunnnarize the preventive measures through which it may be possible to minimize the hazards of coal dust explo­ sions. The properties of coal dust which have an important influence on its explosibility are: fineness, purity, percentage of volatile matter, dryness, age and degree of oxidation, lifting velocities and dispersability, and its static …

Experimental mine and laboratory dust explosion …

01/05/2000· In the limestone rock dust inerting tests in the LLEM, the Pittsburgh coal required about 78–80% rock dust or 80–82% total inert content in the coal–rock mixture in order to prevent explosion propagation. The higher volatility gilsonite required about 10% more rock dust than the coal to be inerted. Two theoretical models based on a calculated, adiabatic limit flame …

Coal dust explosibility

amounts of limestone rock dust required to inert the coals. The effects of coal volatility and particle size were evaluated, and particle size was determined to be at least as important as volatility in determining the explosion hazard. For all coals tested, the finest sizes were the most hazardous. The coal dust explosibility data are compared to those of other hydrocarbons, …

ASSESSING THE EFFECTIVENESS OF INERTIZATION OF BROWN COAL …

Inertization of coal dust with appropriate inert dusts is customary in many coal mines around the world. This method eliminates the potential hazard of occurrence and transmission of coal dust explosion or reduces it to the minimum. Early research conducted by Cybulski (1975) has shown that the use of hydrophobic agents in conjunction with conventional limestone-based rock …

Participation of large particles in coal dust explosions ...

01/01/2014· Commercial pulverized limestone rock dust was used as the explosion inhibitor. In addition to the whole (unsieved) pulverized dust, a number of size fractions were created. Particle sizes <38 μm, 38–75 μm, and >75 μm were produced by manually sieving the original as-received rock dust. A coarse rock dust sample (60-20 mesh or 250–841 μm) was prepared by manually …

2 Effects of Rock Dust Applications on Coal Mine Dust ...

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. TABLE 2-1 U.S. Rock Dusting Regulations

Post-Explosion Observations of Experimental Mine and ...

If a sufficient amount of rock dust is added to the coal dust, the mixture is rendered inert. The rock dusting regulations are based on the results of full-scale experimental mine tests as summarized by Nagy (1 98 1). NIOSH-PRZ, conducts dust explosion research in its Lake Lynn Experimental Mine (LLEM) and in laboratory chambers. Post-explosion dust sampling is part of this research …

[PDF] Rock dusting considerations in underground coal ...

Rock dusting to prevent coal dust explosions has been in widespread use in U.S. underground coal mines since the early 1900s. Underground coal mining technology has changed significantly over this same time period, becoming highly mechanized and produces finer coal dust particles which are more explosive. Despite the advances in mining technology, mine-wide dust …

Recent trends in rock dust modifications for improved ...

01/05/2016· Rock dusting has been used for about 100 years by applying the inert rock dust (typically limestone or dolomite) to increase the total incombustible content of admixtures and effectively quench the flame propagation and coal dust explosion by acting as a thermal inhibitor or heat sink (Rice, 1914; Amyotte et al., 1995, Man and Teacoach, 2009, Cashdollar et al., 2010).

Influence of specific surface area on coal dust ...

01/07/2018· The relationship between the explosion inerting effectiveness of rock dusts on coal dusts, as a function of the specific surface area (cm 2 /g) of each component is examined through the use of 20-L explosion chamber testing. More specifically, a linear relationship is demonstrated for the rock dust to coal dust (or incombustible to combustible) content of such …

Experimental investigations of coal dust-inertant mixture ...

01/01/2011· An experimental investigation was carried out on coal dust-inertant mixture explosions. Tests of explosion severity and flammability limit were conducted by using the Siwek 20 L vessel and influences of ignition energy, coal dust calorific value, coal dust concentration and inertant composition were taken into account. The increase of inerting …

Observations of post-explosion dust samples from an ...

Coal dust explosions in underground coal mines are prevented by a generous application of rock dust (usually limestone). If an explosion should occur, …

[PDF] Rock dusting considerations in underground coal ...

Rock dusting to prevent coal dust explosions has been in widespread use in U.S. underground coal mines since the early 1900s. Underground coal mining technology has changed significantly over this same time period, becoming highly mechanized and produces finer coal dust particles which are more explosive. Despite the advances in mining technology, mine-wide dust …

HazardEx - Preventing coal dust explosions

Accumulations of combustible dust in coal mines create the risk of large-scale explosions that can result in multiple deaths and traumatic injuries. The explosion hazard can be effectively controlled through the application of rock dust, such as limestone dust, to render inert the combustible coal dust generated during the mining and transport of coal.

Influence of specific surface area on coal dust ...

01/07/2018· The relationship between the explosion inerting effectiveness of rock dusts on coal dusts, as a function of the specific surface area (cm 2 /g) of each component is examined through the use of 20-L explosion chamber testing. More specifically, a linear relationship is demonstrated for the rock dust to coal dust (or incombustible to combustible) content of such …

Experimental investigations of coal dust-inertant mixture ...

01/01/2011· The wide use of rock dusts consisting of limestone in coal mining industries gives the idea that calcium carbonate can be applied to prevent or mitigate coal dust explosions. Monoammonium phosphate shows a potential of inerting because it is widely used as the powder extinguishing agent. The combustible-inert mixtures were well-mixed before testing. All the …

Sources of Limestone, Gypsum, and Anhydrite for …

mines rock dust is distributed by hand. AMOUNT OF ROCK DUST REQUIRED It is estimated that the initial application of rock dust should be at least 5 pounds of dust per linear foot of entry, or about 13 tons per mile. From time to time as the proportion of coal dust on the walls and floor increases, the entry should be cleaned and new rock dust ...

(PDF) Waterproof Anti-Explosive Powders for Coal Mines

PDF | Limestone powder characterized by hydrophobic properties is used as an anti-explosive agent in coal mining industry. Unfortunately, the standard... | Find, …

Author's personal copy

the sample to remove the limestone rock dust, sonic sieving to determine the dust size, and low-temperature ashing of the sieved fractions to correct for any remaining incombustible matter. The results indicate that particle sizes of mine coal dust in intake airways are ner than those measured in the 1920s. This ner size coal dust in intake airways would require more …

Marcia L. Harris

• Rock dust particles >200 mesh (>75 µm) provided little benefit to coal dust inerting (20 -L chamber testing) Man, C. K., & Harris, M. L., Participation of large particles in coal dust explosions, Journal of Loss Prevention in the Process Industries 27 (2014), pp. 49-54. Harris ML, Sapko MJ, Zlochower IA, Perera IE, Weiss ES (2015).

Coal Dust Explosions and Their Suppression - Wacław ...

Coal Dust Explosions and Their Suppression Volume 73, Issue 54001 of TT, United States National Technical Information Service Volume 73, Issue 54001 of Translated texts for historians: Author: Wacław Cybulski: Publisher: Foreign Scientific Publications Department, National Center for Scientific, Technical and Economic Information, 1975 ...

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