Evaluation of the effectiveness of coal and mine dust wetting

Abstract Purpose One of the methods of fighting the risk of coal dust's explosion is its neutralization through washing and misting of mining sediment which lays on the mining excavation and through misting on the organs of hewer machines or on the dumpings and inundations of mining product's output. Coal dust, especially its smallest fractions which create the biggest risk of explosion, is generally the substance which cannot be easily moistened by water. Water solutions of different wetting agents are applied in hard bituminous coal mines in order to enhance the effectiveness of coal dust's moistening during the washing and misting. Therefore it is indicated to conduct research and evaluate the effectiveness of its effects in order to select optimally the type of wetting agents and their concentration in water solutions depending on coal dust's properties (type of coal the particular dust comes from) and on percentage participation of non-inflammable parts which are constant in mine dust. This paper presents a method to evaluate the effectiveness of coal or mine dust's moistening conducted with the use of water solutions of wetting agents in order to deprive the dust of its volatility, is based on the method of measurement of time of complete moistening of that dust's one-gram samples with the use of “pure” water or water solutions of the particular wetting agent.