Experimental Study on Blasting Energy Distribution and Utilization Efficiency Using Water Jet Test

Ding, Chuanxian; Yang, Renshu; Lei, Zhen; Chen, Cheng; Zheng, Changda

doi:10.3390/en13205340

Cited by 5 publications

(3 citation statements)

References 11 publications

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“…The reflected wave propagating inside and the subsequent blasting gas work together to continuously expand and compress the original media in the blasthole. In this process, the explosive gas continues to expand, the volume increases, and the pressure decreases; the initial air is compressed, the volume decreases, and the pressure rises (Ding et al, 2020). At the time when the pressure of the explosion gas reduced by the expansion is equal to the pressure of the original air in the blast hole, an equilibrium state is reached at this time, the expansion and compression process ends, and a quasi-static pressure is formed in the blast hole.…”

Section: Quasi-static Pressure Promotes Crack Propagationmentioning

confidence: 99%

Study on improving the gas extraction efficiency by deep-hole pre-split blasting in Wulunshan Coal Mine, Guizhou

Yang

Zheng²,

Li³

et al. 2022

Front. Earth Sci.

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Due to the low permeability of the coal seam and the low gas extraction rate in conventional boreholes in the Wulunshan Coal Mine in Guizhou, in this study, the deep-hole pre-split blasting method is applied to study the improvement of the gas extraction efficiency by increasing the permeability of the coal seam. The study comprehensively expounds the process in which the deep-hole pre-split blasting method is applied to improve the gas extraction efficiency and proposes a numerical simulation method that combines ANSYS/LS-DYNA and COMSOL Multiphysics. Using the method, the initiation of blasting fracture channels and the subsequent influence on the gas extraction range have been comprehensively and directly researched and analyzed. Finally, some theoretical research has been verified by field experiments. According to the recorded simulation of the Wulunshan Coal Mine, the exposed area of the blasting borehole was 42 times the size of the conventional drilling borehole, and the pressure relief space was 1,050 times that of the conventional drilling borehole, which can connect about 32 m3 of coal. Compared with conventional drilling boreholes, in the process of gas extraction, the control range of the controlled pressure reduction was 4–7 times, the range of gas pressure reaching the standard was 25 times, and the peak pressure was reduced by 3–5 times. The average gas concentration was 1.85 times that of conventional boreholes, and the cumulative gas extraction volume of blasting boreholes was 4.48 times that of conventional boreholes. The research results prove that the application of blasting and permeability enhancement in the coal seam with a high gas content and low permeability can effectively improve the gas extraction efficiency in the Wulunshan Coal Mine in Guizhou.

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Section: Quasi-static Pressure Promotes Crack Propagationmentioning

confidence: 99%

Study on improving the gas extraction efficiency by deep-hole pre-split blasting in Wulunshan Coal Mine, Guizhou

Yang

Zheng²,

Li³

et al. 2022

Front. Earth Sci.

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“…Through the water jet test, Ding C.X. et al [12] found that the energy of the blasting gas and the blasting stress wave accounted for about 64% and 36% of the total energy produced by the explosion. Goto A. et al [13] simulated volcanic explosions through field explosion experiments.…”

Section: Introductionmentioning

confidence: 99%

Calculation Method of the Blasting Throwing Energy and Its Variation Affected by the Burden

et al. 2022

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Precise control of casting velocity and effective throwing kinetic energy conversion efficiency in blasting engineering are challenges. To provide a theoretical basis and reference for the implementation plan and fine construction of the cast blasting project, we study the problems of casting velocity and energy consumption ratio of broken rock under the impact load of explosions in this manuscript. The calculation methods of casting velocity and throwing energy of broken rock under two blasting modes of spherical charge and cylindrical charge are established by using the theory of dimensional analysis and rock breaking by blasting. A large number of model tests are carried out by using high-speed photography. The results indicate that the casting velocity of broken rock after explosive initiation has two evident stages: instantaneous acceleration to a certain value and subsequent fluctuation; the velocity presents an ordinary distribution law with the step height, and the fitting correlation of high-speed photography results is more than 91%. With the minimum burden increasing from 0.12 m to 0.2 m, the energy consumption decreases from 1306.88 J to 747.49 J and the proportion of energy consumption decreases from 14.77% to 8.45%.

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“…e Brazilian and international admissibility standards of blasting-induced vibration, the minimum distance between the mine and the community, and the constants obtained from the regression were used to establish the maximum explosive charge per delay for an acceptable ground vibration level that would not cause structural damage and human discomfort [20]. For the cylindrical charge, many scholars combined dynamic caustics, super dynamic strain testing, and numerical analysis methods to study the explosion stress and strain field of the cylindrical charge and the evolution law of the local stress field at the tip of the explosion crack [21][22][23][24]. Some scholars have also conducted intensive research on the different charge structures of columnar drug packs.…”

Section: Introductionmentioning

confidence: 99%

Optimization and Application of Spacing Parameter for Loosening Blasting with 24‐m‐High Bench in Barun Open‐Pit Mine

Zhang

Wang

et al. 2021

Shock and Vibration

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In view of the near slope blasting in Barun open-pit mine, which has merged sublevel mining, the operation safety conditions of middle-sized and large equipment in the second phase expansion are poor and need urgent improvement. To increase the efficiency of expansion and reduce costs, a 24-m-high bench and large spacing parameter for loosening blasting are proposed. The analysis of the physical mechanism of the stress wave attenuation in the rock indicates that the cylindrical charge is equivalent to several spherical charges. Considering the pressure attenuation, reflection, transmission, and superposition of the spherical charge after the equivalence, a double exponential function correction equation of the stress wave attenuation is obtained based on the Mises strength criterion. The stress of any point in the rock medium with various spacing parameter is obtained by calculation. ANSYS/LS-DYNA was used to simulate and study the stress distribution of a 24-m-high bench with various spacing parameter. Meanwhile, the accuracy of the correction equation was verified. The parameters of the high-bench blasting with good effect and low cost were determined to be 15 m × 5.5 m, and field tests were carried out. Results show that the large spacing parameter for 24-m-high bench loosening blasting in Barun open-pit mine is efficient and economical in medium-hard rock blasting. This study provides a reference for the practical exploration of the expansion of high benches in open-pit mines in China. The calculation error of the corrected double exponential function is near the numerical simulation result. It is suitable for all kinds of professional designers.

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Experimental Study on Blasting Energy Distribution and Utilization Efficiency Using Water Jet Test

Cited by 5 publications

References 11 publications

Study on improving the gas extraction efficiency by deep-hole pre-split blasting in Wulunshan Coal Mine, Guizhou

Study on improving the gas extraction efficiency by deep-hole pre-split blasting in Wulunshan Coal Mine, Guizhou

Calculation Method of the Blasting Throwing Energy and Its Variation Affected by the Burden

Optimization and Application of Spacing Parameter for Loosening Blasting with 24‐m‐High Bench in Barun Open‐Pit Mine

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