Ejector-type blast-hole chargers

1980 ◽  
Vol 16 (6) ◽  
pp. 574-579
Author(s):  
I. I. Sentsov
Keyword(s):  
Blast Hole

scholarly journals Application and Development of an Environmentally Friendly Blast Hole Plug for Underground Coal Mines

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Donghui Yang ◽  
Yixin Zhao ◽  
Zhangxuan Ning ◽  
Zhaoheng Lv ◽  
Huafeng Luo
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Low Cost ◽  
Blast Hole ◽  
Environmentally Friendly ◽  
Test System ◽  
Industrial Test ◽  
Labor Intensity ◽  
Rock Blasting ◽  
Hopkinson Pressure Bar ◽  
The Impact

Drilling and blasting technology is one of the main methods for pressure relief in deep mining. The traditional method for blasting hole blockage with clay stemming has many problems, which include a large volume of transportation, excess loading time, and high labor intensity. An environmentally friendly blast hole plug was designed and developed. This method is cheap, closely blocks the hole, is quickly loaded, and is convenient for transportation. The impact test on the plug was carried out using an improved split Hopkinson pressure bar test system, and the industrial test was carried out in underground tunnel of coal mine. The tests results showed that, compared with clay stemming, the new method proposed in this paper could prolong the action time of the detonation gas, prevent premature detonation gas emissions, reduce the unit consumption of explosives, improve the utilization ratio, reduce the labor intensity of workers, and improve the effect of rock blasting with low cost of rock breaking.

The Dynamic Stress Characteristics of Air-Decked Bench Blasting under Soft Interlayer

2011 ◽  
Vol 101-102 ◽  
pp. 400-404
Author(s):  
Liang Wu ◽  
Dong Xiao Yu ◽  
Wei Dong Duan
Keyword(s):  
Dynamic Stress ◽  
Near Field ◽  
Blast Hole ◽  
Material Model ◽  
Explosion Energy ◽  
Element Analysis ◽  
Charge Structure ◽  
Soft Interlayer ◽  
Bench Blasting ◽  
Project Construction

In modern mining and project construction, how to make use of the explosion energy effectively is the key technology demanding prompt solution at present. The application of air-decked blasting technology has enabled the efficient use of explosion energy, which proves that the air-decked blasting technology can overcome many disadvantages caused by column charge effectively, getting ideal explosion effect. Based on the dynamic finite element analysis software with the material model of Mat-Plastic-Kinemetic, the dynamic stress characteristics and failure mechanism of blast-hole near-field with level soft interlayer are researched with different air-decked charge structures. There is significant effect on the rock at the middle of blast-hole if top-air-decked charge structure with indirect initiation and middle-air-decked charge structure with two ends initiation at the same time. If bottom-air-decked charge structure with indirect initiation, soft inter-layer don’t change the peek of compression and tensile stress curves of typical elements with distance from the bottom of hole, so there is not effect significantly of level soft interlayer on bottom-air-decked charge structure with indirect initiation.

scholarly journals A Preliminary Study on the Design Method for Large-Diameter Deep-Hole Presplit Blasting and Its Vibration-Isolation Effect

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Shuangshuang Xiao ◽  
Hongsheng Wang ◽  
Guowei Dong
Keyword(s):  
Vibration Isolation ◽  
Design Method ◽  
Blast Hole ◽  
Large Diameter ◽  
Field Testing ◽  
Open Pit ◽  
Vibration Velocity ◽  
Deep Hole ◽  
Charge Mass ◽  
Presplit Blasting

Presplit blasting can reduce vibration and back impact induced by cast blasting, thus resulting in a smooth bench slope. To design reasonable presplit blasting parameters, this research investigated the formation of presplit faces based on the explosion mechanics and revealed the cracking mechanism of presplit blasting. According to the stress distribution in the vicinity of the blast holes under the action of explosive stress waves and blasting gas, we deduced theoretical formulae for parameters including charge mass in blast holes, hole spacing, and distance from presplit blast holes to cushion holes. On this basis, a method was proposed for the design of large-diameter deep-hole presplit blasting. Field testing was conducted by setting different spacing for presplit blast holes, to monitor the blasting-induced vibration. The results showed that appropriate hole spacing can reduce the particle vibration velocity and the attenuation index of blasting-induced vibration changed slightly while the attenuation coefficient decreased significantly; the formed presplit faces were smooth and had a high half-cast factor. Finally, the reasonable hole spacing for presplit blasting, distance from presplit blast hole to the cushion hole, and the charge mass in blast holes in the Heidaigou open-pit coal mine were determined, respectively.

Automated Blast Hole Logging and Design

1983 ◽  
Vol 16 (15) ◽  
pp. 697-707
Author(s):  
D.E. Scheck ◽  
L.H. Mitchell ◽  
G.W. Mack
Keyword(s):  
Blast Hole

scholarly journals Application of the emulsion explosives in the tunnels construction

2019 ◽  
Vol 123 ◽  
pp. 01039 ◽  
Author(s):  
Oleh Khomenko ◽  
Maksym Kononenko ◽  
Inna Myronova ◽  
Mykola Savchenko
Keyword(s):  
Blast Hole ◽  
Hazard Index ◽  
Emulsion Explosive ◽  
Technical Standards ◽  
Emulsion Explosives ◽  
Atmospheric Air ◽  
Technical Parameters ◽  
Safety Requirements ◽  
Scientific Technical

The analysis has been made of the technical parameters of the existing passport for drilling and blasting operations (DBO) in terms of compliance with labour safety requirements and scientific-technical standards. The methodology for constructing the DBO passport has been developed, which takes into account the areas of blast-hole groups and the properties of emulsion explosives. The type of the cut has been analysed, modelled and accepted for use, which corresponds to the conditions of tunnelling as much as possible. The zones of deformation and fracturing in the massif around blast-hole charges have been simulated. The level of decrease in the hazard index for atmospheric air has been set when using the emulsion explosive Ukrainit-PP instead of TNT-containing charge – Ammonite No.6 ZhV.

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