Assessment of the Impact of Blasting Operations on the Intensity of Gas Emission from Rock Masses: A Case Study of Hydrogen Sulfide Occurrence in a Polish Copper Ore Mine

The article evaluates the impact of blasting operations with explosives on hydrogen sulfide (H2S) emissions from rock mass in a copper ore mine. The study showed that detonations of explosives cause increased release of H2S and other gases from the rock mass interior into the mine workings space. Analysis of changes in H2S concentration over a period of ±60 min relative to the moment of detonation, performed for data from 2014 and 2017, revealed significant differences in gas behavior. In 2014, the average H2S concentration decreased after the blast, while in 2017, a marked increase was observed, although the absolute values were lower than in the previous period. The average time to reach the maximum concentration of H2S after an explosion in 2014 was 24 min and 25 s, and in 2017, 29 min and 22 s. Stabilization of the mine atmosphere occurred in 2014 after 58 min and 15 s, and in 2017 after about 40 min and 57 s. In none of the analyzed periods did the concentration values exceed the threshold of 7 ppm, which means that the level of H2S did not reach the values considered dangerous for the crew. The results indicate that blasting works significantly affect the dynamics of gas release from the rock mass, but do not pose a threat under the conditions studied.