Examination of the role of moisture content on the spontaneous combustion of coal (SCC)

The percentage of moisture content is one of coal’s inherent characteristics, which has a crucial aspect in the occurrence of the spontaneous combustion of coal (SCC) and has long been an attractive issue for analysis among scientists. A complete understanding of this phenomenon helps experts in the prediction and prevention of its occurrence. For this reason, the present work predicts this phenomenon based on moisture content. Thus, a final conclusion about the effect of this parameter was determined. Fifty-one coal samples with different percentages of moisture content were collected from underground coal fields in Iran for the practice training and testing of crossing point temperature (CPT) and R70 test methods. Then, the method of regression analysis was used for modelling and predicting the SCC tendency. The results showed that coal samples were oxidized most rapidly when the moisture content supply was under 20%, and it can reduce the prevalence of the SCC in situations when the moisture was in excess of 20% because the heat released by oxidation is used to evaporate the moisture. For validation and testing, 13 coal samples of another coalfield were collected and CPT and R70 test methods were carried out. The results of the test methods were compared through regression equations. The results obtained from the models indicate a good appropriate prediction in terms of the determination of the SCC tendency by regression analysis.