Journal articles on the topic 'Blasthole charge'
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Yang, Renshu, Changda Zheng, Liyun Yang, Jinjing Zuo, Tonglei Cheng, Chenxi Ding, and Qing Li. "Study of Two-Step Parallel Cutting Technology for Deep-Hole Blasting in Shaft Excavation." Shock and Vibration 2021 (May 7, 2021): 1–12. http://dx.doi.org/10.1155/2021/8815564.
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In hard rock deep-hole blasting excavation, blastholes are rarely utilized due to the clamping effect of the lower rock, which affects excavation progress and restricts the development and application of deep-hole blasting technology. Cut blasting is a key to improving excavation speed. In this paper, a new cutting method designating the two-step cutting technology was presented. The blasthole was divided into upper and lower sections without changing the blasthole layout. The upper section was detonated first, creating sufficient free surface for the lower section, which was detonated secondly. This created a larger cavity and improved blasthole utilization. Results showed good blasting effects for two-step cutting technology through theoretical analysis and engineering applications. The blasthole utilization rate was 96.1% when the upper and lower specific charge ratio = 0.78. This paper provides a good reference for resolving the low blasthole utilization problem in deep-hole blasting of vertical shafts within a hard rock.
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Leshchinskiy, Alexandr, Evgeniy Shevkun, Yuriy Lysak, and Andrey Plotnikov. "Features of schemes of the explosive loosening, with big slowdowns." E3S Web of Conferences 192 (2020): 01024. http://dx.doi.org/10.1051/e3sconf/202019201024.
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The task of the article is to determine the influence of the blasting charge power on the intensity of preliminary destruction of the blasting block mass at long delays. Increase of the destruction radius r from the blasthole charges action at diagonal pattern of hole-by-hole blasting, caused by change of explosive charge energy or rock properties, decreases the number of stress waves passing in the vicinity of specific blast holes. They cause the rock disturbance in the pre-destruction area due to increasing of explosion energy absorption in the area of blasthole charges destruction. However, at the same time, the value of the predestruction factor increases. The calculation shows that 3.5 times increase of the blasthole charge destruction radius, reduces in 1.36 times the number of stress waves passing through the vicinity of specific blasthole charges, but the factor of pre-destruction intensity increases tenfold and the total impact of these factors – by a factor of 8.
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Umarov, Farkhodbek, Utkir Nasirov, Gafur Nutfulloev, Zoir Nazarov, and Lazizzhon Sharipov. "Improving the efficiency of tunneling underground mine workings with the use of blasthole charges with Munroe effect." Izvestiya vysshikh uchebnykh zavedenii Gornyi zhurnal, no. 3 (May 14, 2020): 15–23. http://dx.doi.org/10.21440/0536-1028-2020-3-15-23.
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Introduction. Various techniques of breaking rock by explosion have currently been developed when tunneling underground mine workings, but asymmetrically directed stress fields application is of the main interest. Research aim is to study explosion energy distribution and maximum concentration deep down the blasted rock mass. Blast energy concentration may be achieved by using the principle of cumulation in the hole back by means of changing the design of the blasthole explosive charge. Methodology. Based on the analyzed literature and theoretical research it is recommended to use the design of a blasthole explosive charge with the use of Munroe effect, which makes it possible to increase the blasthole efficiency ratio (BER), reduce drilling activity, reach sharper design contours of mine workings and eliminate bootlegs. The action of blasthole explosive charges with Munroe effect has been theoretically investigated, hydrodynamic theory of cumulation has been studied, and the dependences have been determined between the liner’s collapsing angle alternation and the radius of the cone, its height, initial velocity, and cumulative jet velocity. Results. The main factors which determine the efficiency of the proposed new technique of blasting against the basic technique are the blasthole efficiency ratio, face advance pace after one blast, the amount of rock mass detached after one blast, and the granulometric composition of the blasted rock mass. Summary. The developed design of the blasthole explosive charge with Munroe effect makes it possible to increase BER, face advance per one cycle, and increase the amount of the broken rock mass.
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Sergei D., Viktorov, Zakalinskii Vladimir M., Shipovskii Ivan E., and Mingazov Rafael Ia. "New aspect of drilling development and application in today’s mineral extraction." Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal, no. 6 (September 24, 2020): 5. http://dx.doi.org/10.21440/0536-1028-2020-6-5-13.
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Introduction. The method of applying the factor of short period delay initiation in rock blasting and its effectiveness can be substantiated by the technical possibility of applying it for both conventional inter-row and current downhole delay intervals. The state of the art in blasting has made it possible to implement the technology of a short period delay. So it is rather relevant and extremely difficult to study of the technology’s aspects in full-scale production conditions. Methodology. This work analyzes the options for rock blasting and blasthole charges designs in order to find out how to implement them in a new and more effective way in modern conditions. A well-known method has been chosen, which combines the rock blasting method and the unconventional design of the blasthole charge. It is used as an example to demonstrate the possibility of expanding the practical range of the selected charge placement schemes. This work has been the first to introduce a hypothesis on the possibility of achieving the same effect in two different designs of blasthole charges, but "acting" in almost the same range of short period delay (SPD) use. The fact is that "vertical" distances between downhole short-delay detonators in a conventional blasthole charge (in this case, a single charge) and "horizontal" distances between parallel converged wells of a beam are almost the same. In this regard, it has become possible to focus not on its "internal" content on the "external" one and explain the features of these mechanisms by means of computer simulation. Due to the apparent specific character of conducting a blast in production conditions and intricate experimental observation, this approach is more realizable in practice and the only possible one. 12 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 6. 2020 ISSN 0536-1028 Results. It is proposed to test various methods of blasting (detonation) based on the idea of replacing (transforming, transferring) the explosion action of detonators ( ≥ 1) in a single well charge (conventionally large diameter) with the detonation of ( ≥ 1) lines of a beam of converged borehole charges of the corresponding small diameter. As soon as the number of beam charge design options increases, the range of research options that can lead to the results with improved quality expands significantly. To achieve this goal, the action of various configurations of charges with in-line short period delay blasting in a beam was studied. It should make it possible to come up to some recommendations for blast control. Summary. On the one hand, the proposed blast patterns show the technological departure from the traditional circular shape of the blast wave, on the other hand, they allow using the effect found in the course of numerical experiment for various purposes, in particular, to ensure blasting effect on (interaction with) design features of various mining methods and production systems in complex geomechanical environment
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Sher, E. N., L. V. Gorodilov, and A. G. Chernikov. "Loosening cone of an annular blasthole charge in soft ground." Journal of Mining Science 33, no. 5 (September 1997): 422–26. http://dx.doi.org/10.1007/bf02765616.
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Yang, Renshu, Shizheng Fang, Aiyun Yang, Huanzhen Xie, and Liyun Yang. "In Situ Stress Effects on Smooth Blasting: Model Test and Analysis." Shock and Vibration 2020 (January 7, 2020): 1–14. http://dx.doi.org/10.1155/2020/2124694.
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Most of the roadway excavation is completed by the drilling and blasting method. With the increase of buried depth, the existence of ground stress will generate a significant impact on the rock blasting, especially on the smooth blasting. In this study, self-made homogeneous similar materials and digital image correlation methods were used to determine influence of ground stress on the smooth blasting under uniform explosive charge parameters and various in situ stress conditions. The results show that the crack outline after blasting changes from zigzag to straight in shape, and multifractal calculation results of the rupture section between blastholes show that the fracture surface becomes flatter as ground stress increases, which is conducive to roadway formation. The strain and equivalent strain rate obviously decrease as the distance between the blasthole and measuring points increases. The same trend occurs as the confining pressure goes up. Meanwhile, a postexplosion acoustic wave test indicates that confining pressure inhibits damage of the retained rock, which is consistent with strain and equivalent strain rate results. Finally, we discussed the crack propagation mechanism of rock in smooth blasting.
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Gao, Qidong, Wenbo Lu, Zhendong Leng, Zhaowei Yang, Yuzhu Zhang, and Haoran Hu. "Effect of Initiation Location within Blasthole on Blast Vibration Field and Its Mechanism." Shock and Vibration 2019 (December 6, 2019): 1–18. http://dx.doi.org/10.1155/2019/5386014.
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In drill and blast, the explosive filled in each blasthole is cylindrically shaped and generally initiated by the detonator. Thus, the effect of the initiation location must be addressed, as it determines the detonation direction along the entire column explosive. In this paper, the effect of the initiation location on blast vibration field and its acting mechanism were comprehensively investigated through the theoretical, computational, and experimental approaches. The results indicate that the initiation location plays an important role in the blast vibration filed of the cylindrical charge. The underlying effect of the initiation location can be regarded as the combined results of the energy distribution and phase delay effects of the column explosive source. The behavior of the rock mass in the single-hole blasting experiment demonstrates that the explosion energy is preferentially transmitted to the forward direction of the detonation wave. The seed wave-based computation model verifies that owing to the phase delay effect, the blast vibration field of the cylindrical charge is not uniformly distributed and is strengthened at the forward direction of the detonation wave. The production blasting experiment indicates that the ground PPV under bottom initiation is 61.3%∼211.7% larger than that under top initiation. In addition, the effect of the initiation location is sensitive to the charge length L and the denotation velocity D. Meanwhile, the effect of the initiation location vanishes with distance. The present study provides valuable reference for understanding the effect of the initiation location on blast vibration in drill and blast.
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Yu, Jianxin, Zhibin Zhou, Xin Zhang, Xiaolin Yang, Jinxing Wang, and Lianhao Zhou. "Vibration Response Characteristics of Adjacent Tunnels under Different Blasting Schemes." Shock and Vibration 2021 (December 28, 2021): 1–13. http://dx.doi.org/10.1155/2021/5121296.
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The vibration caused by the tunnel blasting and excavation will harm the surrounding rock and lining structure of the adjacent existing tunnels. This paper takes a two-lane large-span highway tunnel as the research object, conducts on-site monitoring tests on the impact of vibration caused by the blasting and excavation of new tunnels on the existing tunnels under different blasting schemes, and analyses in detail the three-dimension vibration velocity by different excavation footages. From the vibration speed, it is concluded that the influence of the existing tunnel of the newly built tunnel blasting team is affected by various factors, such as distance, free surface, charge, and blasthole distribution. With different blasting schemes, the greater the amount of charge, the greater the vibration caused by blasting. Existing tunnels correspond to the front of the tunnel, and the axial and radial vibration peaks are greater than the vertical. Although the cut segment uses a less amount of explosive and has a less blasthole layout, there is only one free surface. Because of the clamping of the rock, it is compared with the other two segments. The vibration caused is the largest. Although the peripheral holes are filled with a large amount of explosive, the arrangement of the blast holes is relatively scattered and there are many free surfaces. Hence, the vibration caused is the smallest. Corresponding to the back of the tunnel face, since there is no rock clamp, the vibration caused by the cut segment is the smallest, and the vibration caused by the peripheral segment and the floor segment is relatively large. The vibration caused by the front explosion side is significantly greater than the vibration caused by the back explosion side. The vibration velocity caused by the unit charge of 1.5 m footage is greater than that of the 3.0 m footage. The vibration velocity caused by the unit charge of the cut segment is the largest, and the vibration velocity caused by the peripheral segment and the floor segment is smaller. The research results provide a reference for the blasting control of similar engineering construction.
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Ye, Hai Wang, Dong Ling Nong, Ting Li, and Jie Wang Ye. "Numerical Simulation of Mixed Emulsion Explosive Charging in Water-Filled-Hole." Advanced Materials Research 634-638 (January 2013): 3563–66. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3563.
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When charging in water-filled-hole with emulsion mixed loading truck, if the charging hose can not reach the borehole bottom, there will be a water column in the charge. Emulsion explosive charging in water-filled-hole is simulated under three conditions with different water levels, charging velocity and hole diameter when the hose of the explosive mixed loading truck does not reach the hole bottom. The results show that explosive can not reach the bottom of the blasthole if the water depth exceeds the maximum effective range of the jet flow, which is proportional to charging speed and hole diameter, and there will exist a water column at the bottom of the hole. To prevent that, the distance between the hose outlet and the hole bottom must be shorter than the effective range when charging. Besides, increasing charging velocity also works.
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Borovkov, Iurii A., and Temur M. Iakshibaev. "THEORETICAL STUDIES OF CHANGES IN FRACTURE ZONES RADIUS IN THE ORE PILE OF HEAP LEACHING WITH CAMOUFL ET BLASTHOLE CHARGE EXPLOSION." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII GORNYI ZHURNAL 5 (August 6, 2019): 30–36. http://dx.doi.org/10.21440/0536-1028-2019-5-30-36.
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Ramulu, M. "Development of a New Blast Vibration Prediction Model Incorporating Burden Variations in Surface Blasting." International Journal of Geotechnical Earthquake Engineering 1, no. 2 (July 2010): 72–88. http://dx.doi.org/10.4018/jgee.2010070106.
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The globally followed common vibration predictor model includes distance from source to vibration monitoring location and quantity of explosive charge per delay without giving much consideration to blast design parameters. Though there are qualitative assertions on the influence of burden on the vibration intensity by many researchers, no work on quantification of influence of burden has been reported. This paper deals with the development of a predictor model incorporating burden deviations in the existing predictor equation. The influence of burden on the vibration was viewed from the angle of detonation and rock fracturing during blasting. The new predictor equation is based on existing models developed by other researchers on the influence of burden on the blasthole pressure and vibration intensity as well as on some logical assumptions. The influence of burden on vibration was examined in two independent phases of blasting, and the net effect was calculated by adding the influence in both the phases. The study provides a quantitative explanation for the common observations of increased vibration levels produced by the blast rounds with excess burden and/or misfired shots.
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Anan’in, A. V., A. N. Dremin, C. Cunnigham, S. A. Koldunov, B. P. Kryukov, A. V. Lebedev, and Yu M. Litvinov. "Energy release of mixed explosives during propagation of a nonideal detonation under conditions similar to the operation conditions of a blasthole charge." Combustion, Explosion, and Shock Waves 43, no. 4 (July 2007): 468–75. http://dx.doi.org/10.1007/s10573-007-0064-8.
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Zairov, Sh Sh, Sh R. Urinov, and R. U. Nomdorov. "Ensuring Wall Stability in the Course of Blasting at Open Pits of Kyzyl Kum Region." Gornye nauki i tekhnologii = Mining Science and Technology (Russia) 5, no. 3 (October 19, 2020): 235–52. http://dx.doi.org/10.17073/2500-0632-2020-3-235-252.
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Involvement of deep deposits in mining predetermined the trend of development of open pit mining towards increasing the depth of open pits. The main limitation imposed on drilling and blasting in the near-contour zone of an open pit is the need to protect the pit walls and engineering structures on the walls from seismic effects of huge blasts. As practice shows, the most effective and proven method of protecting pit walls is the use of blasting by presplitting method, creation of a shielding gap and a shielding layer of blasted rock mass, i.e. pre-splitting of the pit walls, preceding the huge blast. Therefore, the study of stress-strain state of the near-contour rock mass, determination of the parameters of blastholes for edge pre-splitting (preliminary shielding gap formation) in open pits is an urgent task. The analysis of the pit wall design and stress-strain state of rock mass at Kokpatas deposit exploited by Navoi Mining and Metallurgical Combine allowed to determine the model, as well as the method for calculating stress-strain state of the rock mass. When assessing stability of the pit walls, an approach known as the displacement method was used. Applying the boundary integral equations method allowed to develop an algorithm for calculating stresses in the rock mass for the conditions of Kokpatas deposit. A technique has been developed for experimental studies of blasting contour blasthole charges (blasting by pre-splitting method) using models, allowing to study fracturing on volumetric models and wave interaction by the method of high-speed video recording of the blasting process in transparent models, as well as to determine the parameters of stress waves during blasting in samples of real rocks. A method for formation of stable pit wall slopes, an excavator method for bench pre-splitting on ultimate envelope (contour) of a pit, and a method for initiating blasthole charges in the near contour zone of a pit have been developed and implemented in the industry.
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Ma, Xingen, Manchao He, Jiandong Sun, Haohao Wang, Xiaoyu Liu, and Enze Zhen. "Neural Network of Roof Cutting Blasting Parameters Based on Mines with Different Roof Conditions." Energies 11, no. 12 (December 11, 2018): 3468. http://dx.doi.org/10.3390/en11123468.
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The design and construction of roof cutting and blasting is a key part of the roof cutting pressure releasing gob-side entry retaining (RCPRGER) technology. In the existing research, the blasting parameters of roof cutting have been primarily determined by field tests. However, the disadvantages of field tests include a complicated process, which hinders the succession of related procedures, and an unstable roof cutting effect. Therefore, in this work, the authors attempt to use a mathematical analysis method to simplify the design process of the key parameters of roof cutting blasting. First, the mechanics process mechanism of surrounding rocks with roof cutting and pressure releasing is investigated, and the stress evolution process of the surrounding rock is divided into the following six stages: original rock stress state, excavation stress state, supporting stress state, roof cutting stress state, premining stress state, and postmining stress state. Furthermore, the relationship between roof cutting and entry retaining from the perspective of Mohr’s stress circle is discussed. Next, using four typical mines, including the Tashan, Yuanlin, Jinfeng, and Hengyuan coal mines, as examples, the existing design methods of roof cutting and blasting, geological data characteristics of each mine, distribution rule of roof cutting connectivity rate, and explosive charge structure of roof cutting blasting are summarized. Based on these results, the logic of roof cutting blasting design is obtained, the key indices affecting blasting design are determined, and the blasting design is defined as a complex fuzzy problem with multiple factors. Finally, based on the study of the above mechanics mechanism and blasting rule, a three-layer back propagation (BP) neural network, including six input units, nine hidden units, and three output units, is developed with the four typical mines as the sample space. This neural network realizes the rapid determination of the three key parameters pertaining to sealing length, blasthole spacing, and the explosive charge weight of a single hole. Through training, the calculation error is less than 0.48%, which considerably simplifies the design process of the blasting parameters. The charge structure parameters can also be determined according to this method. At present, the construction of this neural network has the shortcomings of limited sample space. This problem can be overcome by supplementing the sample size in the subsequent research and practice, which will improve the efficiency and accuracy of this design method and promote the application and development of the RCPRGER technology. The interdisciplinary research reported in this paper is an attempt that uses an intelligent algorithm to simplify the design process of roof cutting blasting in RCPRGER, and it represents not only an application development of the intelligent algorithm, but also a new step regarding the intelligent design of RCPRGER technology.
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Azarkovich, A. E., and M. B. Étkin. "Characteristics of the action and calculation of blasthole crater charges." Hydrotechnical Construction 32, no. 1 (January 1998): 32–38. http://dx.doi.org/10.1007/bf02905887.
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Yang, Liyun, Siyu Chen, Pengxiang Dong, Qingcheng Wang, and Chen Huang. "Orthogonal Analysis and Numerical Simulation of Rock Mechanics Parameters in Stress Field of Shaft Heading Face." Advances in Materials Science and Engineering 2020 (November 26, 2020): 1–11. http://dx.doi.org/10.1155/2020/3107364.
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This paper focuses on improving the blasting effect of the drilling and blasting method in the deep rock mass and solves the problems of blasthole collapse and misfire accident in the process of drilling and blasting construction of heading face. FEM software, ABAQUS, is used to simulate the stress distribution around the blasthole by extending a certain depth in the vertical direction of the shaft heading face. The sensitivity of different depths, different heading face sizes, and different lithologies on the horizontal stress distribution is analyzed by using a six-factor four-level orthogonal analysis method. The results show that the change of the radius of the heading face has the most considerable influence on the distance of the distressed zone and the stress concentration zone, followed by the lithology and the excavation depth. Also, the excavation depth has the most significant influence on the peak stress value. Through the industrial field experiment, the in situ stress of the shaft heading face is tested, and the numerical simulation results are consistent with the field monitoring results. The results reveal the law of stress distribution near the heading face, which can provide some reference for the design of blasthole depth in the drilling and blasting construction scheme.
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Sokolov, Igor, Yuri Antipin, Kirill Baranovsky, and Artem Rozhkov. "About the effectiveness of counter blasting with chamber mining system." E3S Web of Conferences 192 (2020): 01017. http://dx.doi.org/10.1051/e3sconf/202019201017.
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When underground mining of Ural copper deposits with a chamber mining system, an urgent scientific and practical task is to increase the productivity of loadingdelivery machines for the ore drawing from secondary chambers. The technogenic disturbance of the massif of such chambers in combination with the non-alternative use of a blasthole ring scheme of breaking leads to an increased output of oversized fractions. With an increase of oversized ore output, operating costs for the drawing and delivery of ore increase, tire wear, fuel and lubricants consumption increases. In this article, the possibility of reducing the oversize ore output in secondary chambers by using counter blasting of the breaking layers is considered. As a result of the research, the parameters of effective counter blasting with blasthole ring charges were established, namely, the distance between the working faces in the chamber, the angle of ore pieces meeting and the line of least resistance.
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Smirnov, A. A., K. V. Baranovskiy, and A. A. Rozhkov. "Application of resource-saving principles at breaking of strong fractured ores by blasthole ring charges." Mining informational and analytical bulletin, no. 3-1 (March 20, 2020): 300–312. http://dx.doi.org/10.25018/0236-1493-2020-31-0-300-312.
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During underground mining of deposits of valuable non-metallic raw materials, nonferrous and precious metal ores, the problem of their overgrinding as a result of blasting is quite acute. Overgrinding of valuable non-metallic raw materials leads to an actual decrease in the yield of concentrates or final products, due to the rather stringent requirements of the enrichment technology for the conditional size of the piece and the structural safety of the useful component. Non-ferrous and precious metal ores represented by strong rocks are characterized by the effect of increased concentration of ore minerals in small classes of ore. Due to the process of segregation on ore drawing, small fractions in significant quantities accumulate on the lying side of the goaf and its unevenness. Such ore with a high content of useful component requires additional technological measures for its extraction or is simply lost. Consequently, the development of technological methods for managing the quality of products of a mining enterprise and methods for increasing the completeness of extracting mineral resources are an urgent scientific and technical task. To solve it, an analysis of theory and practice in the study area was carried out, which showed that the existing methods for additional extraction of fine ore fractions in mining systems with an open goaf are laborintensive and resource-intensive, not universal, ineffective and often not safe. It is rational to create conditions for reducing the yield of fine fractions already at the stage of ore blasting As a result, determining parameters principles for breaking technology of strong fractured ores are proposed. Developed guidelines and recommendations for blasthole ring charges. Dependences the technical and economic indicators of ore explosive blasting from its structural and technological parameters are obtained.
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Поплавський, Володимир Антонович, Віктор Георгійович Кравець, Азер Меджидович Шукюров, and Валерія Володимірівна Павленко. "Physical and technological factors of the formation of detonation capacity of blasthole charges of emulsion explosives." Journal of Zhytomyr State Technological University. Series: Engineering, no. 1(79) (June 20, 2017): 197–201. http://dx.doi.org/10.26642/tn-2017-1(79)-197-201.
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Sher, E. N. "Development of a system of plane radial cracks during explosion of linear blasthole and borehole charges." Journal of Applied Mechanics and Technical Physics 58, no. 5 (September 2017): 933–38. http://dx.doi.org/10.1134/s0021894417050200.
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Gao, Qidong, Zhendong Leng, Ruipeng Yang, Yaqiong Wang, Ming Chen, Pengchang Sun, and Sheng Luo. "Mathematical and Mechanical Analysis of the Effect of Detonator Location and Its Improvement in Bench Blasting." Mathematical Problems in Engineering 2020 (June 4, 2020): 1–14. http://dx.doi.org/10.1155/2020/6058086.
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The outcome of bench blasting significantly affects the downstream operations in mining. In bench blasting, the explosives charged in blastholes are generally cylindrically shaped and fired by the in-hole detonator. As the detonator determines the propagation of the detonation wave in the cylindrical charge, the effect of detonator location can never be ignored. In this paper, the mathematics and mechanics of the effect of detonator location was analyzed from the view of the distribution of explosion energy and blast stress field of a cylindrical charge. Then, a field blasting experiment and two numerical simulations were conducted to further display its effect on blasting outcomes. At last, the appearance of oversize boulders and rock toes in bench blasting was discussed, and an improved scheme of the detonator location was proposed to cope with these problems. Results indicate that the in-hole detonator has the capacity of adjusting the spatial distribution of explosion energy and blast stress field in the surrounding rock mass. The traditional recommendation of the bottom detonator is not always right. The optimized detonator location in bench blasting is available by properly combining the merits of traditional detonator locations. This study is of interest to improve the efficiency and reduce the cost of mining.
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Rymarchuk, Borys, and Oleksandr Shepel. "Ways of increase of efficiency of drilling-and-blasting." E3S Web of Conferences 166 (2020): 03001. http://dx.doi.org/10.1051/e3sconf/202016603001.
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Results of theoretical researches and industrial experiments on technology of breaking of a massif with use of the artificial screens formed by lumbago of blasthole charges are resulted. In research the technology of breaking of ore by means of the vertical concentrated charges (VCC) on in advance formed screens is offered at underground mining. Possible ways of improvement of technology of working of deposits which will provide reduction of a production cost of ore are considered. The effective variant of a location of chisel developments, charges of the vertical concentrated charges (VCC) and artificial screens in the block is considered. It is analyzed the basic variants of formation of a shielding layer at breaking of ore by fans of deep boreholes and a location of boreholes in the coupled fan. The effective sequence of breaking of ore and necessary parameters of drilling-and-blasting is offered at underground mining. Comparison of results of measurements of granules of metric structure of the crushed mass on experimental sites of an ore mine is considered, analyzed and spent. The method of increase of efficiency of passage of the reflected and broken waves through the screen is offered at ore breaking. The considerable effect from explosion of charges in the presence of zones of unloading is resulted with is artificial they formed screens at massif destruction by the vertical concentrated charges.
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Ngoc, Minh Nguyen, Ping Cao, and Duc Thang Pham. "Establishment automatically contour blasting passport for tunnel in AutoCAD by VOLVN 3.0 software." E3S Web of Conferences 174 (2020): 01021. http://dx.doi.org/10.1051/e3sconf/202017401021.
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The smooth blasting method has been researched, developed and strongly applied for long-term underground construction, such as principal mining excavations, tunnels and hydroelectric projects... with the main purpose of minimizing the explosion impact on rock and creating a well-shaped boundary. In this research, a software was developed to establish automatically the tunnel contour blasting passport in AutoCAD. Using the software in each blast design model, it is quickly possible to determine number of blastholes, specific charge, specific drilling and drawing automatically of blasting passport in AutoCAD. The interaction between the software and AutoCAD is a new and important factor that helps to complete an automatically closed cycle on computer from introducing parameters to designing blasting passport in AutoCAD, thereby contributing to increase efficiency of production and minimize risks in blasting works.
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Sher, EN. "Determination of shapes and sizes of radial cracks formed by blasthole charges and hydraulic fracturing in a layered rock mass." IOP Conference Series: Earth and Environmental Science 773, no. 1 (May 1, 2021): 012025. http://dx.doi.org/10.1088/1755-1315/773/1/012025.
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Koteleva, Natalia, and Ilia Frenkel. "Digital Processing of Seismic Data from Open-Pit Mining Blasts." Applied Sciences 11, no. 1 (January 2, 2021): 383. http://dx.doi.org/10.3390/app11010383.
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This article describes an approach of mathematical processing of signals (seismograms) from five blasthole charges from experimental blasting, each 3 m deep, with equal explosive weight (1 kg), and equidistant (3 m) from one other. The seismic explosive waves were measured at a 13 to 25 m distance. This article provides spectral analysis, wavelet analysis, and fractal analysis results. It defines the dependence of dominant frequency and amplitude on the distance to the blast center. According to the experimental data, the dominant frequency is calculated as y = 1.0262x0.2622 and the amplitude dependency as y = 18.139x−2.276. Furthermore, the analysis shows that 80% of the entire signal is concentrated in half the area of frequency range, i.e., the low frequency zone is of the most interest. This research defines the dependence of distance on the energy value of signal wavelet analysis. It is demonstrated that, according to the experimental data, the 12th frequency range is closely correlated with the distance values. This article gives the definitions of entropy, correlation dimension, and predictability time. This experiment shows that entropy and correlation dimension decrease but predictability time increases when the distance to the blast center increases. This article also describes the method for determining optimal drilling and blasting parameters, and concludes with the possibility of applying the analytical results to predicting and enhancing drilling and blasting operations.
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Kononenko, Maksym, and Oleh Khomenko. "New theory for the rock mass destruction by blasting." Mining of Mineral Deposits 15, no. 2 (2021): 111–23. http://dx.doi.org/10.33271/mining15.02.111.
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Purpose. To develop a new theory for the rocks destruction by blasting using a description of the formation processes of zones with various mass state around the charging cavity. Methods. The new theory for the rock mass destruction by blasting has been developed based on the use of the well-known elasticity theory laws and the main provisions of the quasi-static-wave hypothesis about the mechanism of a solid medium destruction under the blasting action. The models of zones of crumpling, intensive fragmentation and fracturing that arise around the charging cavity in the rock mass during its blasting destruction, depending on the physical and mechanical pro-perties of the rock mass, the energy characteristics of explosives and the rock pressure impact, have been developed using the technique of mathematical modeling. Findings. Based on the mathematical modeling results of the blasting action in a solid medium, the mathematical models have been developed of the zones of crumpling, intensive fragmentation and fracturing, which are formed around the char-ging cavity in a monolithic or fractured rock mass. Originality. The rock mass destruction by blasting is realized according to the stepwise patterns of forming the zones of crumpling, intensive fragmentation and fracturing, which takes into account the physical and mechanical properties of the medium, the energy characteristics of explosives and the rock pressure impact. Practical implications. When using the calculation results in the mathematical modeling the radii of the zones of crumpling, intensive fragmentation and fracturing in the rock mass around the charging cavity, it is possible to determine the rational distance between the blasthole charges in the blasting chart, as well as to calculate the line of least resistance for designing huge blasts.
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Chen, YingXian, Jian Chen, PengFei Wang, Meng Zhou, HongXia Yang, and JiaYing Li. "Design method of blasthole charge structure based on lithology distribution." Scientific Reports 11, no. 1 (December 2021). http://dx.doi.org/10.1038/s41598-021-03758-y.
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AbstractThe density of geological exploration boreholes is one of the main bases for blasthole charge structure design. Due to the low density of geological exploration boreholes, it is impossible to obtain the blast hole rock formations' distribution accurately. With the development and application of intelligent drilling rigs, the lithology distribution data of the blasthole can be accurately obtained, and a blasthole charge structure design method based on the lithology distribution is proposed. The blasthole lithology data collected by the intelligent drilling rig is divided into 7 categories according to the rock hardness, and the adjacent strata with similar lithology are combined and divided into two groups of soft rocks and hard rocks. According to the rock stratum grouping data of the blasthole and the unit explosive consumption of each type of lithology, the explosive amount and charge length required for the soft rock group and the hard rock group can be calculated, respectively. Finally, the blasthole charge structure is designed according to the thickness and charge position of the hard rocks. With the C++ programming language, this method is realized and applied in the Shengli Open-pit Coal Mine of Inner Mongolia Autonomous Region of China. The application results show that, compared with the traditional hole charging structure design method, this method can realize accurate segmented charging of the hole, improve the blasting effect and the degree of rock fragmentation, and reduce the blasting cost.
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Zhao, Dan, Zhiyuan Shen, Minghao Li, Baichen Liu, Yinuo Chen, and Lina Xie. "Study on parameter optimization of deep hole cumulative blasting in low permeability coal seams." Scientific Reports 12, no. 1 (March 24, 2022). http://dx.doi.org/10.1038/s41598-022-09219-4.
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AbstractCoal seam gas extraction is an important means of exploiting and utilizing gas resources, as well as a means of preventing coal mine disasters. To improve gas extraction efficiency in high gas and low permeability coal seams while ensuring blasting security, deep hole cumulative blasting parameters were optimized. ANSYS/LS-DYNA software is used to establish a 3-dimensional cumulative blasting model. By comparing and analyzing the blasting stress nephograms, stress time-history curves, and crack expansion curves, the optimal blasthole diameter, charge position, and charge length are obtained. Based on the numerical simulation results, a field test was carried out in the No. 10 coal seam of the Pingdingshan coal mine. The test results show that after cumulative blasting, the gas concentration was increased by an average of 2.25 times, the gas purity was increased by an average of 3.78 times, the permeability coefficient of the coal seam was increased by 21 times, and the effective radius of blasting was up to 7 m. The positive effects of deep hole cumulative blasting parameter optimization on the pressure relief and permeability enhancement of a high gas and low permeability coal seam were determined, which can provide a reference for other similar working faces to implement this technology.
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"Development of a System of Plane Radial Cracks in Explosion of Linear Blasthole and Borehole and Burning Charges." Прикладная механика и техническая физика, no. 5 (2017). http://dx.doi.org/10.15372/pmtf20170520.
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"DETERMINATION OF SHAPES AND SIZES OF RADIAL CRACKS FORMED BY BLASTHOLE CHARGES AND HYDRAULIC FRACTURING IN A LAYERED ROCK MASS." Фундаментальные и прикладные вопросы горных наук 6, no. 1 (2019). http://dx.doi.org/10.15372/fpvgn2019060146.
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Tyupin, V. N. "Initiation of residual stress zone during blasting in jointed granite rock mass in operation of Priargunsky Industrial Mining and Chemical Union." Gornyi Zhurnal, October 30, 2020, 60–64. http://dx.doi.org/10.17580/gzh.2020.10.04.
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Russian and foreign technical literature says that blasting in jointed rock mass induces zones with altered physical properties and geomechanical behavior beyond the perimeter holes. These zones are identified as the crushed zone, radially fractured zone, spalling zone and shattered zone. The shattered zone lacks scientific attention although this zone can reach the width of (30–170)db (db—blasthole diameter) in open pit mines and (25–75)db in underground mines. The earlier implemented research answers the question on quantitative change in the stresses and strains of a jointed rock mass during blasting. The initiation mechanism of the shattered zone remains unclear. This study aims to find the initiation mechanism of the shattered zone in jointed rock mass and to determine its stress state after blasting. Three series of full-scale experimental studies have been performed in jointed granite rock mass using acoustic emission methods, ultrasonic techniques and deformation measurements. It is found that in the shattered zone, blocks in the jointed rock mass displace radially from the blast holes with deformation of the joint surfaces and with elastic strains preserved after blasting. For this reason, this zone is qualified as the zone of blast-induced residual stresses. The article gives the formula for the residual radial compressive stresses under short-delay multi-row blasting. The numerical calculation using this formula and the actual mine data prove the formula validity. The method of destressing blasting is proposed to unload rockburst-hazardous rock mass from stresses in the areas of the confining pressure phenomena such as spalling and sloughing. This method has been trialed in Priargunsky’s mines in granite rock mass (1400 m long area was unloaded from stresses in mines). The authors highly appreciate participation of I. I. Shishkin, B. M. Belyaev, V. M. Pankov and V. A. Pazdnikova in the experimental research.