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

Surface coal mining procedures include piercing-blasting-mining and loading-transportation-discharging, blasting link exists due to the poor blasting effect leads to low loading efficiency, blasting dust caused by environmental pollution and other problems. In this paper, from the mechanical characteristics of the water medium, we analyze in detail the transferring effect, transducing effect and bubble pulsation phenomenon of the water medium in the blasting process. The results show that when the blasting medium is water medium, the maximum principal stress is 1.53 times that of air medium; the peak energy transfer can be up to 2.73 times that of air medium. With the help of TrueGrid/LS-DYNA finite element analysis software to simulate the dynamic process of blasting, the study of the maximum principal stresses around the hole, the top of the slope, the foot of the slope on the maximum principal stress changes, the results show that the maximum principal stresses around the hole, the top of the slope, the foot of the slope unit with the increase in the water content is gradually increasing trend. Finally, combined with the actual mine production conditions for blasting field test, water-mediated blasting dust reduction rate of 75%, the use of AHP-fuzzy comprehensive evaluation method of two groups of traditional dry hole blasting and three groups of water-mediated blasting comprehensive evaluation, the results show that the water-mediated blasting scores are higher than the traditional dry hole blasting, proving that the water-mediated blasting has a certain prospect of engineering applications.

Study on Crust-Shaped Dust Suppressant in Non-Disturbance Area of Open-Pit Coal Mine-A Case Study.

Dust pollution in open-pit coal mines severely restricts the green development of mines. Therefore, dust control has become an important requirement for the sustainable development of the mining industry. With the goal of dust pollution prevention and control in open-pit coal mines, this paper puts forward the concept of a non-disturbance area of an open-pit coal mine. It clarifies the characteristics of dust generation, the coverage area, and the dust particle size distribution characteristics of the non-disturbance area. Taking the dust control at the dump site as an example, the study comprehensively utilizes indoor tests and field tests to develop a dust suppressant for the dump site and determine its dust suppression efficiency and effective service cycle. The results show that the D10, D50, and D90 particle sizes of dust in the non-disturbance area are smaller than those in the disturbance area, and the difference in particle size of D90 is the most obvious. Gelatinized starch and non-ionic polyacrylamide, as the main components of the dust suppressant, can effectively reduce dust pollution in the dump; the optimal concentration is 1.0%, and the dust suppression service cycle is more than one month. The developed dust suppressant does not contain corrosive, toxic, or heavy metal elements. Although the application of a dust suppressant will cause plant growth to lag, it does not affect plant health. The research findings serve as a reference for the zoning treatment of dust in open-pit mines.

Annual dust pollution characteristics and its prevention and control for environmental protection in surface mines.

Dust pollution is a critical challenge in achieving green mining of open-pit coal mines. The scientific basis for dust prevention and management hinges on a thorough understanding of the long-term characteristics of dust pollution. However, analyzing the characteristics of long-term dust pollution in open-pit coal mines has always been a void in research due to the effect of the mines' geographical location and operating conditions. This research investigated the dust pollution and delved into its key production and meteorological influencing elements in a cold-region open pit coal mining. The real-time data was monitored on-site during the four seasons of the year. The characteristics of dust pollution were determined by statistical analysis. The main factors affecting the dust concentration in different seasons were calculated using the comprehensive grey correlation degree. Finally, dust pollution from the mine to the surrounding area was simulated using the Hybrid Single Particle Lagrangian Integrated Trajectory model. The results revealed that dust pollution was most serious in winter, followed by autumn, spring, and summer. The concentrations of PM10 and PM2.5 exceed the national limit. Meteorological elements that substantially impact dust concentration vary season by season. The dew point temperature in spring, the solar radiation in summer and autumn, and the boundary layer height in winter were the most important elements. Mining activities pollute the surrounding areas more in winter, followed by autumn and spring. During the winter, the pollution is concentrated in Shanxi, while in the autumn and spring, it is concentrated in Inner Mongolia. Based on the research findings, optimal mine design strategies can be devised to avoid and regulate dust in mining and neighboring areas, especially during winter.