THE USE OF EXPLOSIVES IN SURFACE MINING
or eliminates the amount of secondary blasting while minimizing wear ... When rocks are extremely well jointed blasting ratios as high as 15 tons per lb of explosive may be obtained. The volume of rock on each of a row of shotholes is approximately a prism, with dimensions equal to the burden, the spacing and the depth of ...
ANALYSIS OF DRILLING AND BLASTING PARAMETERS TO ACHIEVE OPTIMUM ROCK
The properties of rock such as strength, porosity, density, sonic velocity, blastability index, effect of rock disturbances and rock structure may have a significant influence on blasting results (Hartman, 1996). 2.6.1 Rock structure The rock structure may be defined using the frequency and orientation of bedding planes, joints and other ...
Blasting Techniques & Safety Measures
Primary blasting involves breaking down of in-situ rock in development and stopping as well as by drilling holes in rocks. Secondary blasting is performed to get rid of overburden. Drill and blast ...
(PDF) A brief history of the development of blasting and the …
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.
Research progress of the fundamental theory and technology of rock blasting
Investigating rock fragmentation mechanisms under blasting and developing new blasting technologies are important and challenging directions for blast engineering. Recently, with the development of experimental techniques, the fundamental theory of rock blasting has been extensively studied in the past few decades and has made important …
Rock Fragmentation Evaluation towards Blast-To-Mill …
Drilling and blasting operation is one of the most critical activities that affect production in hard rock mining. Extensive production of boulders and fines associated with in-situ blasting are the main challenges of hard rock mining. Poor blast outputs considerably affect downstream operations including loading, hauling, crushing, and …
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 …
Sk Pr Sec Blasting
Skills Programme Description: Secondary Blasting Operations for Underground Hard Rock . 2. 3. Registration Number: 4. Total Credit Value: Minimum of 36 5. Band on the NQF FET 6. Field ... Break big rocks using a secondary breaker . 2 . 3 . 18 . 12 . 116636 . MnH-G208 . MnH-G808 . 244405 .
How to Carry out Controlled Blasting of Rocks? [PDF]
🕑 Reading time: 1 minute The main objectives of controlled blasting techniques are to minimize the overbreak and fracturing of rock beyond the designated boundary of excavation to achieve smooth post-blast surface and to control wild flyrock and ground vibration within permissible limits.
secondary blasting of rocks
Secondary Blasting Of Rocks. Secondary Blasting Article About Secondary Blasting By The. In secondary blasting, explosive denotation release a huge amount of energy which results to rock shattering and scattering and consequently high fly rocks. The labour cost for secondary blasting can be expressed as a percentage of the labour cost for ...
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.
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, depends upon strength, fracture spacing and other factors, which can be assessed by geophysical or geotechnical techniques. 31, 32
11th International Symposium on Rock Fragmentation …
11TH INTERNATIONAL SYMPOSIUM ON ROCK FRAGMENTATION BY BLASTING / SYDNEY, NSW, 24–26 AUGUST 2015 T N LITTLE 344 3. Profile control blasting – profile control involves using blasting to create three-dimensional (3D) space in a previously solid rock. The primary blasting objective is to achieve the design profile (3D shape) for …
The Influence of Explosive and Rock Mass Properties on …
In rock blasting for mining production, stress waves play a major role in rock fracturing, along with explosive gases. Better energy distribution improves fragmentation and safety, lowers production costs, increases productivity, and controls ore losses and dilution. Blast outcomes vary significantly depending on the choice of the explosive and …
(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 ...
Numerical Study on an Innovative Shaped Charge Approach of Rock …
The blasting energy of the charge in borehole is transmitted to the rock by the combined action of the primary shock waves and the subsequent detonation products, which can provide instantaneous impact stress and durative quasi-state stress (Cho et al. 2004; Ning et al. 2011; He and Yang 2019).As for the BGSC blasting, when the …
How to Carry out Controlled Blasting of Rocks? [PDF]
Thus it is crucial to control the adverse effects of blasting. 1. Factors Affecting Vibration. …
Drilling and Blasting of Rocks
Rock breakage with explosives has existed since the seventeenth century when black powder came into use in mining. Since then it has progressed from the invention of dynamite to the use of heavy ANFO. During the past two decades, there have been numerous technical contributions which have brought a better understanding of …
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 …
An Overview of Blasting Operations and Possible Techniques …
Blasting is accompanied by a number of side effects that have a negative impact on the environment, such as ground vibration, flyrock, AOp, and backbreaks [33, 42].These effects are more severe if they are carried out in close proximity to residential buildings, factories, offices or if they are improperly designed [].Proper designing of a …
What are the techniques and hazards in drilling …
Blasting in a mine generally occurs in two phases, primary blasting and secondary blasting. Primary blasting involves breaking down of in-situ rock in development and stoping as well as by drilling …
(PDF) Optimization of Blast Design for Quarries: …
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 ...
Blasting Principles
Blasting. Using explosives to break rock. Blasthole. A hole drilled into a rock to be filled with explosives for blasting. ... It is used to initiate less sensitive or secondary explosives. Modern blasting relies on detonators for the safe and precise control of explosive energy release to achieve desired blast outcomes.
A review on the prediction and assessment of powder factor …
Drilling and blasting are fundamental operations in the mining cycle and constitute an important component of the mining costs. Rock fragmentation can in principle be managed by means of two options: by increasing or reducing the specific consumption of explosives, or by modifying the drilling pattern.
(PDF) ROCK BLASTING FOR MINING
After a production blast, a secondary blast may be required to reblast a portion of the rock to reduce it to a size fit for …
A rapid evaluation method of blasting effect based on
The blasting effect of the drill-and-blast method is comprehensively judged by primary indicators such as safety, quality and economic benefits in the blasting process and secondary indicators ...
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 …
RIIBLA305A Conduct secondary blasting
RIIBLA305A Conduct secondary blasting Modification History Not applicable. Unit Descriptor This unit covers conducting secondary blasting in resources and infrastructure industries. It includes: planning and preparation; conducting blasting; and completing blasting operations. Application of the Unit
Cracks propagation characteristics of double-hole delay blasting …
By researching the distance between blasthole and interface of soft-hard rock strata, as well as the time of delay detonation, blasting effect of the rock mass will be more controllable. Firstly ...
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 ...