Investigation of explosibility characteristics of some Turkish lignite coal dusts

Abstract

ABSTRACTThe aim of this study is to create sufficient quantitative explosibility data for lignite coal dust samples obtained from three different regions of Turkey for safe design and operation of underground coal mines, process and storage facilities. Investigation of explosion characteristics of dust samples were performed with 20-L Siwek sphere test apparatus. Maximum Explosion Pressure (Pmax), Lower Explosion Limit (LEL), Maximum Rate of Explosion pressure rise (dp/dt)max and the Explosibility Dust Constant (KSt) values were measured. KSt values of Turkish lignite coal dust samples vary between 136 and 142 bar m/s. The data obtained from the explosion tests present reasonably good agreement with those tests for similar type of coal dusts studied earlier and have explode under suitable conditions. It is also understood that the lignite coal dusts may explode on very low concentrations (30-60 g/m3) when compared with Turkish hard coal dust (250 g/m3). The coal dusts with 50% moisture content (on the original basis) such as Elbistan low grade coal are present explosive properties when they lost their moisture. It is important to take account the explosibility characteristic of Afşin-Elbistan low-grade and high moisture content for safe design of process and storage facilities. The rock dusting operation should be strictly maintained in the underground lignite coal mines. Soma lignite coal dust with its 30 g/m3 LEL value can explode at lower concentration compared with the other high volatile Turkish lignite coal dusts. The Pmax values were observed to increase in proportion to the increase in the calorific value.