Pollutant Migration Pattern during Open-Pit Rock Blasting Based on Digital Image Analysis Technology

Abstract

Previous studies have revealed that toxic gases and dust (smoke dust) are the most common pollutants generated by the blasting operations in open-pit mines, which might lead to a threat to the environment’s condition, health and safety, and properties protection around the blasting site. In order to deal with the problems, a pollution evaluation system was established based on the fractal dimension theory (Dbox(P)) and grayscale average algorithm (Ga) in digital image-processing technology to recognize and analyze the distributions of the smoke-dust cloud, and subsequently determine the pollution degrees. The computation processes of Dbox(P) and Ga indicate three fitted correlations between the parameters and diffusion time of smoke dust. Then, a pollution index (Pi) is put forward to integrate the global and local features of Dbox(P) and Ga, and develop a hazard classification mechanism for the blasting pollutants. Results obviously denote three diffusion stages of the pollutants, mainly including generation stage, cloud-formation stage, and diffusion stage. In addition, it has been validated that the proposed system can also be utilized in single-point areas within a whole digital image. Besides, there are variation trends of the thresholds T1 and T2 in binarization with the diffusion of pollutants. With this identification and evaluation system, the pollution condition of smoke dust can be obviously determined and analyzed.

Research on blasting mechanism and blasting effect of aqueous media in open pit coal mines

“…Khazins, V. M. [22,23] studied the initial phase of the formation of hot thin dust and gas clouds after scattering of blast products and the subsequent buoyancy-induced induced rise of the heat, obtaining the relationship between the height of the rise and the size of the gas and dust clouds and the distance between adjacent blasts. Yin, J.J et al [24] developed a pollution evaluation system with a grey-scale averaging algorithm (G(a)) in digital image processing techniques to identify and analyse the distribution of soot clouds and subsequently determine the level of pollution. The calculation process of G(a) showed three fitted correlations between the parameters of soot and the dispersion time.…”

Research on blasting mechanism and blasting effect of aqueous media in open pit coal mines

“…Khazins 22 , 23 , studied the initial stages of the formation of thermally dilute dust and gas clouds after the scattering of the explosion products, obtaining a relationship between the height of ascent and the size of the gas and dust clouds and the distance between neighboring explosions. Yin, et al 24 developed a pollution evaluation system with a gray scale averaging algorithm (G(a)) in digital image processing technique to determine the existence of three fitted correlations between the parameters of soot and diffusion time. Huang, et al 25 studied the mechanism and migration law of blast dust removal, and the results showed that in the stage of impact movement and mushroom cloud formation, the explosive gas generated by the blast expands rapidly, and a large amount of dust is rushed into the atmospheric space under the kinetic energy of the blast impact.…”

Mathematical Problems in Rock Mechanics and Rock Engineering

“…Yin et al [7] proposed a pollution evaluation system based on the fractal dimension theory (Dbox(P)) and the grayscale average algorithm (Ga) in digital image-processing technology to recognize and analyze the distributions of the smoke-dust cloud and subsequently determine the pollution degrees. The results obviously denote three diffusion stages of the pollutants, mainly including the generation stage, cloud-formation stage and the diffusion stage during open-pit rock blasting.…”