The Fifth International Symposium on Mine Safety Science and Engineering (ISMSSE2021)

98 / 2021-09-29 13:51:47

Research on Diffusion of the Blasting Fume in Deep Open-pit Mines

deep open-pit mine; explosive fume diffusion; amount of the explosive material; explosion location; wind velocity

The diffusion of the blasting fume in deep open-pit mines was much more difficult. The blasting fume had threatened the safety of the workers in deep open-pit mines. Based on the real mine, the 2-D model of the deep open-pit mine has been established. The total height of the mine is 90m. The ultimate slope angle is 45°. The height of the step is 15m and the width is 10m. The influence of the amount of the explosive materials, the explosive location and the wind velocity on the explosive fume diffusion was investigated by mathematical and simulation methods. The results showed that for any amount of the explosive materials, the time of the fume concentration descending to 24ppm decreased proportionally with the wind velocity increasing and the diffusion rate in the upwind locations was much more higher than it in the backwind locations. For any wind velocity and amount of explosive materials, when the explosion location was in the upwind side, the time of the fume concentration descending to 24ppm decreased first and then increased with the height of the location decreasing. When the explosion location was in the backwind side, the time of the fume concentration descending to 24ppm increased with the height of the location decreasing. For any wind velocity and explosion location, the time of the fume concentration descending to the safety limit increased proportionally with the amount of the explosive materials increasing and the time was higher than 15min which is the ordinary ventilation time in deep open-pit mines. The research has a positive instruction for the safety production and the mine workers’ health in deep open-pit mines.