Prevention and Control of Hydrogen Sulphide Accidents in Mining Extremely Thick Coal Seam: A Case Study in Wudong Coal Mine

Hydrogen sulphide is a toxic gas often present in coal seams and seriously threatens the lives and health of underground workers in coal mines. In this study, we theoretically modelled hydrogen sulphide generation in extremely thick underground coal mines with the +575 level #45 coal seam of Wudong Coal Mine as an example and obtained the on-site hydrogen sulphide emission pattern and spatial distribution features by combining field measurements and computational fluid dynamics simulation. The results showed that hydrogen sulphide mainly exists in the coal porous system in an adsorbed state. Because hydrogen sulphide has a molecular weight greater than the average molecular weight of air molecules, its concentration decreases with the increase of altitude to the bottom plate. When mining the upper stratified coal stratum, it diffuses widely in the working space; while when mining the lower coal stratum, it mainly concentrates at the bottom of the working face. Based on these analyses, on-site treatments were carried out using mixtures with different concentrations of sodium carbonate and sodium bicarbonate. In addition, different combinations of catalysts as well as type A and type B wetting agents were also tested. Eventually, a neutral KXL-I absorbent was developed, and the process of preinjecting absorbent and spraying absorbent was designed. The results showed that the newly developed KXL-I absorbent has high hydrogen sulphide absorption ability and is suitable for use as an absorbent in Wudong Coal Mine; preinjecting and spraying the absorbent can effectively prevent hydrogen sulphide disasters in the +575 level #45 coal seam in Wudong Coal Mine with the optimal final concentration of 0.9% and the absorption rate of 87% at the shearer of 66.6% at the support. Overall, our study provides valuable information for the prevention and control of hydrogen sulphide disasters in coal mines.

Analysis on Stability of Land Parcel of Fushun Mining Group Headquarters by Exploitation of West Open-Pit Mine

Through calculation on the variation of deformation of land parcel of Fushun mining group headquarters on different exploitation conditions of west open-pit mine, the stability of land parcel of Fushun mining group headquarters has been analyzed. The analyzed results show that when the slope has been excavated to line D and the exploitation is on N1200, the influence for the stability of land parcel is smaller, but when the exploitation is on N1600, because of the concentrated distribution of displacement and obviously enlargement of the scope of plastic zone on the area between the fault F1 and F1A, the stability of land parcel has been changed obviously. At the aim of the security of land parcel of Fushun mining group headquarters, the excavation of slope should not be more than line D and the exploitation of coal stratum should not be more than N1200. The achieved results can provide a research foundation for a reasonable and orderly exploitation for Fushun west open-pit mine.