On the Effect of Increasing Air Pressure with Depth on the Calculation of the Required Amount of Air in the Deep Mines

The effect of increasing air pressure with the depth on the calculation of the required amount of air in the deep mines is analyzed in the work. It is established that with an increase in air pressure, the values of the volumetric maximum permissible concentrations of toxic and explosive gases in it decrease, while their maximum permissible mass concentrations remain unchanged. Failure to consider the decrease in volumetric maximum allowable concentrations of toxic and explosive gases with depth when calculating the required amount of air in the mines in some cases can lead to an underestimation of air flow rates in working areas and, as a result, to an excess of maximum allowable concentrations of harmful gases. To move the same volume of air, local ventilation fans at great depths need to expend more power than at the surface. Therefore, when working at depth, it is required to use local ventilation fans with electric motors of greater power. When air is supplied to a greater depth, it is compressed and the volume flow decreases. Therefore, in order to maintain the required volumes of air at depth, it is required to increase its flow rate at the main fan installation. This should be considered when calculating the required amount of air in deep mines. The results obtained in the work can be applied in the design of deep mines and the development of methods for calculating the required amount of air for them. Based on the conducted research, the method was adjusted for calculating the amount of air used at the Glubokaya mine of the Skalisty mine of the Polar Branch of PJSC MMC Norilsk Nickel.