DETERMINATION OF SAFE VENTILATION OF POST-EXPLOSION PRODUCTS AFTER BLASTING IN MINES

摘要

On the basis of the permissible concentrations of toxic gases CO and NOx in air stated by the safety or sanitary regulations and the technical parameters of blasting agents for blasting operations indicated by the producer, the coefficient of safety Kto is calculated according to the following formula:IMAGEwhere:Kto - coefficient of the security of the ventilation of gas explosion products after blasting operations in mines;Vco - specific volume of CO in the gas explosion products after blasting indicated by the producer in the technical parameters of the blasting agent (m3 kg-1);Vnox - specific volume of NOx in the gas explosion products after blasting indicated by the producer in the technical parameters of the blasting agent (m3 kg-1);NPKco - the highest permissible concentration of CO in the air of the mine stated by the safety or sanitary regulation (%, ppm);NPKnox - the highest permissible concentration of Nox in the air of the mine stated by the safety or sanitary regulation (%, ppm);With the resulting value of the coefficient of safety Kto higher than 1 only the concentration of CO is measured after the blasting operation. If the value of Kto is below 1, only the concentration of Nox is measured. If the measured value of the concentration of CO, or the concentration of Nox in the second case, is lower than the permissible concentration in the working air stated by the safety and sanitary regulations, both toxic gases CO and Nox have been already ventilated and it is possible to enter the workplace.