Rock breakage by explosives

1980 ◽  
pp. 329-340
Author(s):  
T.N. HAGAN
Keyword(s):  
Rock Breakage

Concept of synergetic interaction between rock breakage and geomechanics processes in mineral mining

2019 ◽  
Vol 3 ◽  
pp. 113-124
Author(s):  
S.D. Viktorov ◽  
◽  
V.M. Zakalinsky ◽  
I.E. Shipovskiy ◽  
R.Ya. Mingazov ◽  
...  
Keyword(s):  
Rock Breakage ◽  
Mineral Mining

scholarly journals Advances in Blast-Induced Impact Prediction—A Review of Machine Learning Applications

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 601
Author(s):  
Nelson K. Dumakor-Dupey ◽  
Sampurna Arya ◽  
Ankit Jha
Keyword(s):  
Machine Learning ◽  
Prediction Models ◽  
Academic Research ◽  
Empirical Models ◽  
Rock Breakage ◽  
Environmental Implications ◽  
Learning Methods ◽  
Factors Affecting ◽  
Impact Prediction ◽  
Machine Learning Methods

Rock fragmentation in mining and construction industries is widely achieved using drilling and blasting technique. The technique remains the most effective and efficient means of breaking down rock mass into smaller pieces. However, apart from its intended purpose of rock breakage, throw, and heave, blasting operations generate adverse impacts, such as ground vibration, airblast, flyrock, fumes, and noise, that have significant operational and environmental implications on mining activities. Consequently, blast impact studies are conducted to determine an optimum blast design that can maximize the desirable impacts and minimize the undesirable ones. To achieve this objective, several blast impact estimation empirical models have been developed. However, despite being the industry benchmark, empirical model results are based on a limited number of factors affecting the outcomes of a blast. As a result, modern-day researchers are employing machine learning (ML) techniques for blast impact prediction. The ML approach can incorporate several factors affecting the outcomes of a blast, and therefore, it is preferred over empirical and other statistical methods. This paper reviews the various blast impacts and their prediction models with a focus on empirical and machine learning methods. The details of the prediction methods for various blast impacts—including their applications, advantages, and limitations—are discussed. The literature reveals that the machine learning methods are better predictors compared to the empirical models. However, we observed that presently these ML models are mainly applied in academic research.

Impact pressure distribution of an SC-CO2 jet used in rock breakage

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yong Liu ◽  
Juan Zhang ◽  
Jianping Wei ◽  
Chenchen Wang ◽  
Jiawei Cui
Keyword(s):  
Pressure Distribution ◽  
Impact Pressure ◽  
Rock Breakage

scholarly journals Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yong Liu ◽  
Juan Zhang ◽  
Tao Zhang ◽  
Huidong Zhang
Keyword(s):  
Gas Jet ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Rock Breakage ◽  
Glass Substrates ◽  
Expansion Waves ◽  
Erosion Rates ◽  
Gas Jets ◽  
The Impact ◽  
Nozzle Structure

Abrasive gas jet technologies are efficient and beneficial and are widely used to drill metal and glass substrates. When the inlet pressure is increased, gas jets could be powerful enough to break rock. They have potential uses in coal-bed methane exploration and drilling because of their one-of-a-kind nonliquid jet drilling, which avoids water invasion and borehole collapse. Improving the efficiency of rock breakage using abrasive gas jets is an essential precondition for future coal-bed methane exploration. The nozzle structure is vital to the flow field and erosion rate. Furthermore, optimizing the nozzle structure for improving the efficiency of rock breakage is essential. By combining aerodynamics and by fixing the condition of the nozzle in the drill bit, we design four types of preliminary nozzles. The erosion rates of the four nozzles are calculated by numerical simulation, enabling us to conclude that a nozzle at Mach 3 can induce maximum erosion when the pressure is 25 MPa. Higher pressures cannot improve erosion rates because the shield effect decreases the impact energy. Smaller pressures cannot accelerate erosion rates because of short expansion waves and low velocities of the gas jets. An optimal nozzle structure is promoted with extended expansion waves and less obvious shield effects. To further optimize the nozzle structure, erosion rates at various conditions are calculated using the single-variable method. The optimal nozzle structure is achieved by comparing the erosion rates of different nozzle structures. The experimental results on rock erosion are in good agreement with the numerical simulations. The optimal nozzle thus creates maximum erosion volume and depth.

Damage Analysis and Simulation of Rock under High Pressure Waterjet

2011 ◽  
Vol 462-463 ◽  
pp. 774-779
Author(s):  
Hu Si ◽  
Xiao Hong Li ◽  
Yan Ming Xie
Keyword(s):  
High Pressure ◽  
Damage Mechanics ◽  
Water Jet ◽  
Penalty Function Method ◽  
Impulsive Effect ◽  
Contact Method ◽  
Arbitrary Lagrangian Eulerian ◽  
Rock Breakage ◽  
Pressure Water ◽  
High Pressure Water Jet

The high pressure waterjet is widely applied for mine industry, mechanical manufacture, environmental engineering, and medicine field due to its particular characteristic. Recently, the application of high pressure waterjet for gas drainage in mine has been receiving increasing attention with the development of exploitative technology. The micro-damage mechanism of coal under high pressure water jet is key to drain gas effectively. Based on damage mechanics and rock dynamics, the paper analyzed the micro-structure deformation and damage of rock and the impulsive effect under high pressure water jet and developed the dynamic model. Further, on the assumption of that rock was homogeneous and isotropic, a computational model was established based on the Arbitrary Lagrangian Eulerian (ALE) fluid-solid coupling penalty function method. The rock damage under high pressure water jet was simulated by the dynamic contact method. The results showed that the damage and breakage of ruck was mainly attributed to impacting effect and was characterized by local effect, and the evolvement of rock breakage went through three stages and the figure of rock breakage trended a funnel. On the whole, numerical results agreed with experimental results.

scholarly journals Theoretical Modeling of Rock Breakage by Hydraulic and Mechanical Tool

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hongxiang Jiang ◽  
Changlong Du ◽  
Songyong Liu ◽  
Liping Wang
Keyword(s):  
Theoretical Model ◽  
Water Pressure ◽  
Rock Fracture ◽  
Superposition Principle ◽  
Specific Energy Consumption ◽  
Critical Length ◽  
Rock Fragmentation ◽  
Rock Breakage ◽  
Hydraulic Impact ◽  
Mechanical Tool

Rock breakage by coupled mechanical and hydraulic action has been developed over the past several decades, but theoretical study on rock fragmentation by mechanical tool with water pressure assistance was still lacking. The theoretical model of rock breakage by mechanical tool was developed based on the rock fracture mechanics and the solution of Boussinesq’s problem, and it could explain the process of rock fragmentation as well as predicating the peak reacting force. The theoretical model of rock breakage by coupled mechanical and hydraulic action was developed according to the superposition principle of intensity factors at the crack tip, and the reacting force of mechanical tool assisted by hydraulic action could be reduced obviously if the crack with a critical length could be produced by mechanical or hydraulic impact. The experimental results indicated that the peak reacting force could be reduced about 15% assisted by medium water pressure, and quick reduction of reacting force after peak value decreased the specific energy consumption of rock fragmentation by mechanical tool. The crack formation by mechanical or hydraulic impact was the prerequisite to improvement of the ability of combined breakage.

scholarly journals Experimental and Numerical Investigation of Hard Rock Breakage by Indenter Impact

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hongxiang Jiang ◽  
Zhiyuan Cai ◽  
Ouguo Wang ◽  
Deguang Meng
Keyword(s):  
Energy Consumption ◽  
Impact Velocity ◽  
Impact Energy ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Decisive Role ◽  
Rock Breakage ◽  
Radial Cracks ◽  
The Impact ◽  
Indenter Shape

To investigate the effect of indenter shape, impact energy, and impact velocity on the rock breakage performance, a test device for rock fragmentation by indenter impact was developed to obtain the rock breakage volume, depth, and area under different impact conditions. By comparing the rock breakage volume, depth, area, and specific energy consumption, the results show that indenter shape has a greater influence on the rock breakage performance than that of the impact velocity with the same impact energy, and impact energy plays a decisive role in rock breakage performance with an identical indenter shape and impact velocity. For the lowest to highest specific energy consumption, the order of indenter shape is cusp-conical, warhead, hemispherical, spherical-arc, and flat-top under the same impact energy and velocity, but the cusp-conical indenter is damaged after several impacts. The rock breakage volume, depth, and area all increase with the increase in impact energy, but the effect of the impact velocity could be ignored under the same impact energy. In addition, the rock breakage features of the numerical simulation and experiments are similar, which show that the crushing zone close to the indenter impact point is mainly caused by the high compressive stress, and then radial cracks are caused by the accumulative energy release. The findings of this study will contribute to progress in the performance and efficiency for percussive rock drilling.

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