Effect of calcium chloride solution on the spontaneous combustion of coal using Olpiński method

The article concerns the effect of the additive on the inhibition of the coal spontaneous combustion process (CSC) by the Olpiński method. The influence of inhibitors on CSC in this method has not been studied so far. Coal samples used in the experiment were taken from Polish coal mines, from which four samples with the symbols S1, S2, S3, and S4 were created, respectively. For each coal sample, a spontaneous combustion index was tested following the Olpiński's method. In addition, analogous tests were performed for coal samples treated with an aqueous CaCl2 solution. A 20% CaCl2 solution has proved to be the most advantageous. Based on the Olpiński method, a fire incubation period is determined in natural conditions on a mine site. Based on the results of CaCl2 inhibition, the extension of that period for examined coals was determined. The results obtained can provide valuable references for developing technology in CaCl2 usage to prevent spontaneous fires in coal mines.