Optimized blasting design for large-scale quarrying based …
In this quarrying project, it was planned that the stone products would have a fragment size under 0.03 m 3 and that blasting rock larger than 0.03 m 3 would need secondary blasting by a breaker or a crusher. The production cost, therefore, can be divided into drilling, primary blasting, secondary blasting and crushing costs.
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How to Conduct Blasting Operations Safely? …
What is the process of blasting in hard rock or soil? Blasting is a process of reduction of rocks or hard soil into fragments with the help of explosives. The blasting operation includes drilling of holes, installing a detonator and charge, …
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Chapter 9 GENERAL ROCK REMOVAL
plosives under the rock. SEAM BLASTING is used when the blaster is lucky enough to find a crack or seam, and load the explosive charge into it. The method selected will depend upon a number of factors, including the equipment at hand and the depth of the rock in the earth. Secondary blasting is noisy and generally produces many flying fragments.
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Comparative analysis of hydraulic drop ball and secondary blasting
In secondary blasting, explosive denotation release a huge amount of energy which results to rock shattering and scattering and consequently high fly rocks. Noise As regards the hydraulic drop ball technique, the noise is only limited to that of machine and can be experienced only at the operator's location (cabin).
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Research on directional rock blasting based on different …
The drilling-blasting method 1,2 can harm the surrounding rock, compromising the stability of the rock mass 3,4.Techniques like smooth-surface charge blasting and directional blasting can mitigate ...
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Blasting Mechanics Revisited: The mechanics of rock breakage …
About this four-part series. In 1963, Pit & Quarry published a series of articles on the mechanics of blasting authored by Richard Ash, a longtime professor of mining engineering at the School of Mines & Metallurgy at the University of Missouri-Rolla. The content within each article was ahead of its time, putting forth cutting-edge concepts about the mechanics of rock …
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Three reasons for oversized rocks in the primary crusher …
Secondary blasting is the most efficient, affordable way to resize the boulders. There are multiple ways to reduce the impact of a blast producing oversize boulders. Using a trained geologist to construct a proper drill and blast program, increasing the size of the blasting polygon and ensuring shovel/excavator operators are properly trained ...
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(PDF) Optimization of Blast Design for Quarries: A case …
In hard rock mining, blasting is the most productive excavation technique applied to fragment in-situ rock to the required size for efficient loading and crushing. ... the cost of secondary ...
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Directional rock blasting using shaped charges using …
The drilling-blasting method 1, 2 can cause damage to the surrounding rock, affecting the stability of the overall rock mass. 3, 4 Smooth-surface charge blasting and directional blasting technology can reduce the damage to the surrounding rock, however, these techniques still have many issues, such as overblasting and underblasting, protection ...
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Blast-Induced Rock Fragmentation in Wet Holes
In open-pit mining, blasting pattern design is performed to achieve a desired degree of fragmentation for loading, hauling, and crushing operations. Inappropriate fragmentation of rock will result in numerous problems such as incurring extra costs for secondary blasting, production interruption, etc. Wetness of the blast holes is one of the …
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How to Carry out Controlled Blasting of Rocks? [PDF]
The smooth blasting is also referred to as contour blasting or perimeter blasting. 4. Cushion Blasting. Cushion blasting is like smooth wall blasting, a single row of holes is drilled along the excavation line, loaded with light, well-distributed charges, and fired after the …
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SECTION 2xx—BLASTING FOR ROCK CUT SLOPE …
SECTION 2xx—BLASTING FOR ROCK CUT SLOPE EXCAVATION. 2xx.1 DESCRIPTION—This work is excavation of rock using controlled blasting and production …
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Innovative Blast Design for Reduction of Boulder Generation …
Based on the site visit and initial observations, the following may be the main reasons behind the boulder generation at this mine site: I. Unavailability of free faces: In some of the blasts, there were the unavailability of the proper free faces. It is necessary to ensure the availability of free faces up to the bench height to get the proper breakage of the rock mass.
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Experimental Study of Rock Breakage with Pulsed Water …
Blasting and heavy impact hammers are the main techniques used in mines to fracture oversized rocks, but both impose undesirable extra costs as a secondary rock-breakage operation. Blasting is ...
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Blasting Techniques Used in Underground and Opencast Mines | Mining
Secondary Blasting: Secondary blasting is carried out in two ways: 1. Pop Shooting: A hole is drilled by jackhammer for charging with explosive and blasting the boulder. Normally a depth of 0.3 to 0.6 m is sufficient for most of the boulder sizes. The explosive, widely used, is special gelatine in conjunction with safety fuse or detonators. 2.
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A review of some nonexplosive alternative methods to conventional rock
The conventional blasting rock excavation method is the main means of rock breakage because of its high productivity, and it is relatively inexpensive compared to other methods. However, it raises safety concerns and can negatively impact the environment. The major disturbances that may be induced by this method include flyrock, gas emissions, and vibrations. This review …
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Drilling and Blasting
Secondary blasting or some form of impact breaking are often required to reduce oversized rock fragments after primary blasting. The 'rippability' of a rock body, as an alternative to blasting, …
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Blasting Principles
Reference blasting fundamentals, properties of explosives and blasting principles in this section. For more specific requirements, reach out to our Orica specialists for an in-depth discussion today.
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(PDF) A Review on the Prediction and …
Powder factor can be defined as the quantity of explosives (kg) required to break a unit volume or tonne (t) of rock. The prospect of excavating rocks by blasting is characterized by a specific ...
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Shaping characteristics of excavation contours in sequential …
The locations of rock-anchored beams in underground powerhouses feature high in-situ stress and large blast loads, making it difficult to perform presplitting blasting.
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Drilling and Blasting of Rocks
This work explores rock fragmentation through drilling and explosives. Sections cover various characteristics, methods and types of equipment, including rotary percussive drilling, compressors, industrial explosives, blasting accessories, rock breakage, blasting for tunnels and drifts, underwater blasting, secondary fragmentation and special blasting, and …
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Research progress of the fundamental theory and …
This paper mainly focuses on the experimental study of rock blasting, including the distribution characteristic of blast energy, evolution of the blast stress field, propagation …
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Blasting | Rock Fragmentation, Drilling & Explosives
Blasting, process of reducing a solid body, such as rock, to fragments by using an explosive. Conventional blasting operations include (1) drilling holes, (2) placing a charge and detonator in each hole, (3) detonating the charge, and (4) clearing away …
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Blasting Best Practices | T.M.I.
Cushion blasting techniques are distinct because they save the secondary blasts until after the main explosion. As a final touch-up to the area, these smaller blasts around the edges smooth out the surface for a visual improvement. ... Assessing Rock Type and Nature at Blasting Sites. Different categories of rock respond to explosive substances ...
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An Overview of Blasting Operations and Possible Techniques …
In spite of introduction of new technologies for breaking rock, blasting has remained most popular methodology for breaking rock for surface mining, tunnels, and civil …
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Introduction to Types of Rock Blasting
An investigation into the methods of secondary blasting …
These examples and many others emphasize the important role of rock fragmentation in blast design. Until recent years, when blasting was more of an art than science, most of the above …
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Definition of secondary blasting
Two methods of secondary blasting of rock are available. The first, called the plaster or mudcap method, is to fire a charge of explosive placed on the rock and covered with clay, the shock of …
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Chapter 9 GENERAL ROCK REMOVAL
SECONDARY BLASTING Bench blasting ideally reduces all rock to a desired rubble size range. This is basic in order to facilitate handling of rubble or muck to meet limitations …
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Optimized blasting design for large-scale quarrying based …
Rock fragmentation plays a critical role in large-scale quarrying operations because of its direct effects on the costs of drilling, blasting, secondary blasting and crushing. In this aspect, it is essential to consider rock fragmentation in blasting design.
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(PDF) A Review of the Mechanism, Effects and Control of …
Though rock blasting is a commercially viable venture, it is advised to be careful at the planning stage in order to produce a blast design that will ensure optimum blast result. The design should be made to enhance proper utilization of blasting energy in the rock fragmentation. ... Secondary blasting could either be plaster (mud-cap) blasting ...
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