Identification and Ranking of Factors Affecting the Emission of CO Gas in Karkar Coal Mine

Karkar coal mine is one of the biggest mines in the country, where mining has been going on since 1938. During the mining period, the Karkar mine has witnessed unfortunate incidents caused by the release and explosion of gases, which have caused substantial financial and human losses. Carbon monoxide gas is one of the essential factors in the occurrence of accidents in the Karkar mine. This research includes literature reviews, field data collection using the CEM CO-181 model gas meter, and statistical calculations using Shannon entropy and Promethee methods. First, the concentration of CO gas was measured in ventilation tunnels, development, and excavation areas. Extraction workshops of the Karkar coal mine at different working times, and then 26 cases that may result in a reduction in accidents were used as effective criteria, and 9 cases were used as influential factors on CO emissions through the order and distribution of questionnaires and interviews with identified experts. The final weights of twenty-six effective criteria on the emission of CO gas were calculated based on the Shannon entropy method. As a result, the criterion of consumed oils with a final weight of 0.1790 was ranked first, and the criterion of lack of experience with a final weight of 0.1065 was ranked last. The influential factors have been ranked based on the amount of net flow and the parameter method. As a result, the factors of mining fire and coal dust explosion ranked first and last, respectively, with net flows of 0.55 and -0.84, and the rest of the factors are placed in different positions according to their net flow rate and have their effects on the emission of CO gas.