The recirculation within a deep open-pit mine is a significant
factor contributing to the deterioration of the atmospheric environment.
However, the underlying mechanisms of how recirculation influences
the dispersion pattern of dust clouds within the deep open-pit mine
have not been clearly elucidated. In this research, the dispersion
patterns of blast dust clouds were investigated in a deep open-pit
mine located in northern China. This research initially conducted
a similar experiment to verify the existence of recirculation flow
in the experimental mine, which can cause dust particles to aggregate
toward the upwind slope. In response to the dust pollution issue in
deep open-pit mine blasting operations, this study conducted a numerical
simulation analysis based on on-site measurement data to investigate
the effects of varying natural wind velocity, natural wind direction,
and blast location on the diffusion pattern of blasting dust. The
results indicate that natural wind velocity (v),
natural wind direction (α), and blast location (d) affect the distance between the blast location and the recirculation
center point (D
recir), subsequently influencing
the diffusion pattern of blasting dust. The recirculation flow effect
influences the diffusion of dust toward the upwind slope under smaller D
recir values, leading to widespread and long-term
pollution within the mine. Under larger D
recir values, dust diffuses toward the downwind slope with the straight
flow of wind, resulting in less pollution within the mine. Through
orthogonal experiments, the equation D
recir = −120.61v
2 + 237.27v + 0.82d – 0.07α2
+
6.75α + 151.08 was established in
this deep open-pit mine, which provides a basis for predicting the
diffusion pattern of blasting dust and control strategy in this deep
open-pit mine.