Abstract
An assessment of the effectiveness of inertization of coal dust with inert dust is an important step in prevention of coal dust explosions. According to the tests on their explosive properties, coal dusts from all the mines in Bosnia and Herzegovina present an explosion hazard. The measure applied in order to prevent the transmission of deposited coal dust explosion, in both methaneous and non-methaneous pits, is wetting. The prescribed content of solid non-combustible particles in coal dust which makes the dust non-explosive (defined by BH regulations) Â is based on the figures taken from Polish regulations. In order to get the content of inert component in coal dust which will prevent the transmission of explosion, relevant for BH coals, a research was conducted on brown coal dusts from the three largest producing coal mines in BH. In this case, limestone rock dust was used to inert coal dust. Tests were conducted in accordance with the methods defined by EN 14034-1 and EN 14034-2. The tests conducted indicate that the content of inert component in BH coal dusts differs from the amounts defined by the adopted Polish regulations and, consequently, that BAS (Bosnian and Herzegovinian) standards need to be changed accordingly.
Highlights
Brown coals make 37% of total coal reserves in Bosnia and Herzegovina
Based on the testing of explosive properties of brown coal dust on prepared referent samples from the three coal mines, we obtained the curves of explosion pressure and rate of pressure rise, depending on the concentration of dust with total natural content of inert substance, for d100 and d25
The explosibility of coal dust is observed through its most important indicator, explosive characteristics (Ek), which describes the interactions between the maximum rate of pressure rise, maximum developed pressure and duration of the explosion (Marković et al 2015)
Summary
Brown coals make 37% of total coal reserves in Bosnia and Herzegovina. Brown coal deposits are tectonically complex and their seams are relatively steep. Their conclusion was that the finer the coal dust, the higher the amount of stone dust required to inert the mixture. For the purpose of prevention of coal dust explosions, most countries adopted regulations requiring inert dust (usually limestone rock dust) to be added to deposited coal dust in such an amount to make the mixture incapable of transmissing an explosion (Cain 2003). The aim of the tests is to make a preliminary determination on whether the numbers taken from the Polish regulations with regards to the content of the solid inert substance at which dust loses its explosive properties are correct and applicable on the dust of brown coals mined in Bosnia and Herzegovina. -Explosion severity Kst.max and explosive characteristics Ek were calculated from: Kst dp / dt V1/3 max mbar / s (1)
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