Search Documents

By Ruilin Yang

Kinematic approach of blast modeling refers to using the velocity, strain, or displacement as controlling parameters to model blasting, rather than the stress and the material constitutive relations. The rock stiffness or constitutive relations is very hard or impossible to obtain due to the complexity of the rock mass property.

Feb 1, 2020

By Peter Moser, Mark Ganster, Radoslava Ivanova, Florian Bauer

Blasting accurately in underground drifts and creating a smooth contour requires proper drilling, knowledge about the apparent geology, a well designed blast pattern and ideally a smooth blasting product. These products are usually cartridged explosives with less energy and are charged in the contour holes in order to reduce the energy concentration and therefore the cracking into the surrounding rock. With the development of a new contour blasting system, a device can now be delivered to the industry that that avoids the additional storage of cartridged products when bulk explosives are used. The system consists of a foldable hose that is charged with bulk emulsion, in the same way as the rest of the blast, from the base to the collar of the hole. It centers automatically in the borehole and provides a decoupled charge. The paper describes the system in detail, gives background information on smooth blasting and presents the first successful field tests using the system in the drifts of an underground mine. It shows the advantages of blast results that produce more stable contours that reduce the amount, time and cost for support but also increase safety underground.

Jan 1, 2012

By Jim Peterson, Ricardo Freire, Mason Biernat

Variable nature of rock and face conditions, varying execution and changing nature of blasting are making ongoing optimization challenging. Intelligent planning and on-going analytics are required to mitigate variability and convert blasting into a predictable outcome by use of technology. Blasting operations generate a huge amount of data which can be used intelligently for optimization. In this paper, details are provided of a system which is used for blasting data collection in the field – Key details around blast parameters, explosives, initiating system details, video, photographs, vibration and fragmentation are collected in a cloud-based platform. Data can also be collected through a mobility device in the field (even without internet connectivity) and synchronized with cloud-based system. Also, data from various sources can be imported in excel formats in the software including from upstream and downstream processes from blasting. App also gives indication about exceeding of vibration, air blast overpressure, fragment size etc. Thus, making it possible to perform QA-QC before charging and deciding initiation timing and sequence at the blasting site. The data can be processed and analyzed to spot trends, help predict events, and formulate strategies at the design and execution stage. Data gathering of blast parameters, explosive used processing and analysis can be used to optimize operational efficiency, improve safety and environmental controls.

Jan 1, 2019

By NA NA

Copyright © 2020 International Society of Explosives Engineers

Feb 1, 2020

By Jeffrey Loeb

Recent trends in blasting engineering and its related fields, at the level of professional academia, have tended to exclude detailed discussion and examination of the formative experiences of the engineering student. In particular, the extra-curricular aspects of the undergraduate program in engineering—focused, in this case, on the summer job—will be shown to contain a wealth of heretofore underappreciated knowledge in the field. In Surveying the Damage: Post Traumatic Stress and Pre-Blast Surveys, I intend to outline and examine some of the more unusual experiences afforded me by my work as a preblast surveyor in the summer of 2007. In this capacity, I was required to make a visual note of existing conditions of surrounding residential and commercial structures within 100 m (328 ft) of two separate blasting sites in central-east Ontario. In the interest of both convenience and specificity, I have attempted to organize the paper as a crossdiscipline survey of the field according to the conference’s list of suggested topics. In the paper’s first section, I will discuss the topic of Environmental Improvement and Remediation by using a case study in which not one, but two dead cats were found during the course of a routine pre-blast survey. The second section will undertake a discussion of on-site blaster gossip as an entry point into a wider discussion of Workplace Communications Management. In the paper’s final section, I will detail an early morning encounter with a 300 lb, stark-naked trailer park inhabitant as a cross-sectional analysis of the topics of Drilling in Hostile Environments, Vibration and Seismology (Sizemology?), Ethics in Blasting, Crisis Management, Risk Assessment and Public Relations. It is my hope that this paper will begin to open up a critical space for discussion of the formative experiences of engineering students during the undergraduate university program in terms of their far-reaching effects on later performance within the industry.

Jan 1, 2009

By Tuan Nguyen, Dirk Hummel, Ruilin Yang

In a tunnelling site in Japan, it was found that detonators failed to initiate with their shells and primary explosive intact. Their capacitors, however, were discharged due to some damage on the application-specific integrated circuits (ASICs). These detonators are distinctly different from other commonly observed failures, where the shells are rather crashed due to excessive dynamic pressure received from neighbouring blastholes which fired earlier. Such incident has not been reported elsewhere. Detonator failures during a blast are deemed not safe and can cause disruption on the project productivity. It is therefore desirable to understand the origin of such event. Various measurements were conducted to diagnose the problem, but the root cause had yet to be identified. This paper applies a discovery from a 60-year-prior-laboratory experiment and formulates a theory that could explain the observed detonator failure and predicts the measurements and observations.

Feb 6, 2023

By Rodney Pinksen, Remi Proulx

The IOC Mining and Operations Departments expressed an interest in reducing the amount of oversize material (>1.0 m x 1.0 m x 1.0 m; 39 inches x 39 inches x 39 inches) being produced and its subsequent downstream effects including in-pit sorting and reduction, damage to mobile equipment, and significant delays in the loading pockets and the primary crushers. To achieve this goal an oversize reduction project was undertaken by the mine and to date has significantly improved upon baseline measures.

Jan 1, 2011

By Kia Riihioja, Mike Higgins

A major difference between electronic and pyrotechnic detonators is that, in almost all but the simplest of blast layouts, computer software is required to plan a blast using electronic detonators. While it may be possible to program delay times without software, using only the manufacturer’s control hardware, the full potential of electronic detonators can only be realized through software. Until recently, the only software available has been provided by the suppliers of the electronic detonators. These usually have just enough features to create a hole layout and to assign times to the detonators in the holes. The software is also able to communicate only with the manufacturer’s detonators. This means that the client may be compelled to change several parts of the blasting process when a different delay system is adopted, from design through to implementation and reporting, even though these may be sub-optimal at the client’s mine. While many authors have demonstrated improvements in blasting outcomes using electronic detonators, very few have discussed how the delay times were calculated. Where the calculations are discussed, it is also obvious that the delay times must be monitored and re-evaluated as conditions in the mine change. For example, the principles of superposition and scaled distance, burden relief and energy cooperation between holes should be checked constantly for different locations within the mine, changes in rock properties, or even for differences between design and actual hole positions. The most common methods in blast design software to calculate delay times are inter-hole interval, relief contour and direct editing. Although they are simple in concept, they can result in fundamental errors if they are not applied correctly. The software for electronic blast designs should be capable of not just a timing calculation, but also of showing, to some degree, the impact and interaction of the calculated times.

Jan 1, 2004

By Robert Hopler

Blasting powder is a slow-acting, black, granular explosive made of sulphur, charcoal and either potassium nitrate (saltpetre) or sodium nitrate. The blasting powder containing potassium nitrate is known as “A” blasting powder; that containing sodium nitrate, as “B” blasting powder. “A” blasting powder is a little denser, a little stronger and a little less hygroscopic than “B” blasting powder.

Jan 1, 2014

By Ray Jambakhsh, John Okell, Frank Cook

"In early 1988, an experimental study was carried out at the Inco's McCreedy West Mine inLevack, Ontario. The objective was to develop blasting techniques which would allow themine to maintain production targets and reduce blast induced vibrations and overpressure.Due to its close proximity to the town of Levack (approximately 900 feet), particularconcern was expressed as to the vibration and overpressure resulting from the undergroundblasting operations."

Jan 1, 1993

By J. Silva, M. Kotraba, F. Pontanilla

Blasting is the application of highly complex science that, in some cases, could be viewed as an art. Many variables are involved in a blast, including geology, pattern design, timing and firing sequence, and explosives selection. Assuming that better results can be achieved by only increasing the powder factor is inaccurate. The Drill-to-Mill (D2M) concept has been in the mining industry for over two decades. The D2M approach is commonly viewed in an oversimplified manner, assuming that by simply increasing drilling and the amount of explosives used (both of which add operational costs), the downstream value will be created. An optimized D2M initiative should combine the smart application of explosives at the beginning of the mining process, matching the dynamic properties of the rock to the explosive selected to improve the efficiency of the energy created by the explosive to the rock mass being blasted, and to bring benefits to the mining operation across the entire mining and processing value-chain. This paper reviews the principles behind matching the shock impedance of the rock and the explosive and compares the traditional use of explosives versus the smart application for two hypothetical blasts.

Jan 1, 2024

By David N/A Doucet, Colter N/A Angell, William N/A Joa, Kyle N/A Wagner, Catherine N/A Johnson, Marty N/A Langenderfer

The Kingery-Bulmash (K-B) equations are a widely accepted means of predicting air-blast parameters from surface explosive detonations. The parameters predicted from these calculations include incident and reflected pressure, time of arrival, shock front velocity, incident impulse, reflected impulse, and positive phase duration. K-B calculations are based on curve fitting of experimental data and can be used to predict air-blast parameters for explosive weights from less than 1 kg (2.2 pounds) up to 400,000 kg (440.9 US Tons), and ranges of 0.05 to 40 meters (1.9 inches to 131.2 feet). The K-B equations can also determine the parameters for multiple explosive types using scaled distances and relative equivalency to TNT. An experiment was designed to demonstrate if the measured results for incident pressure, time of arrival, shock front velocity, incident impulse, and positive phase duration equal the expected results reported for the detonation of a small quantity of explosive determined by the K-B Calculator. Three surface-detonated 300-gram (0.66 pound) hemispherical charges of Composition C-4 were observed via high-speed imaging and hydrostatic pressure monitoring. The hydrostatic pressure generated from each charge was measured via piezoelectric pressure transducers at a scaled distance of 10 from the charge epicenter, and at elevations of 0.30, 0.61, and 1.22 meters (1, 2, and 4 feet) above ground level. Variances in experimental values from the K-B predicted values were recorded for each measured blast parameter. Time of arrival, which was redundantly confirmed through high-speed imaging analysis and hydrostatic pressure monitoring, showed the highest deviation from the predicted values at more than double the K-B predicted value. This report compares the observed blast parameters from the test series with the expected blast parameters from the Kingery-Bulmash Blast Parameter Calculator. Differences between the experimental and predicted values are reconciled through analysis and discussion of testing conditions, instrumentation setup, and scaling methods.

Jan 1, 2019

By Joshua Micah Hoffman

While it is easy to state that meaningful involvement of the community can play a critical role for a successful blasting operation, following through with this involvement is not an easy task. Structured Public Involvement (SPI) is a developed protocol for involving communities in project planning decisions and could be readily applied to the blasting industry. SPI was developed for the purpose of collecting quality public input about public transportation projects. The purpose of SPI is to bring about stakeholder satisfaction with potential projects by allowing controlled input from the stakeholders. It was designed and intended for democratic societies that have come to expect a voice in public projects. While blasting operations are not always in the domain of public projects, the fundamental process outlined by SPI can be useful for collecting feedback from the immediate public around blasting operations.

Jan 1, 2014

By AK Chakraborty, AK Raina

Burden of drill hole is third most sensitive parameter effecting the ground vibration in blasting apart from maximum charge per delay and distance. Various types of burdens can be seen in practical bench blasting situations. Burden can be expressed as drilled burden and initiation burden. Drill holes may have various front row burdens (toe burden), which may be different from the designed burden. In order to ascertain the impact of front row burden as well as the initiation burden on intensity of ground vibration and air overpressure experiments were conducted in sandstone overburden benches of an opencast coal mine and limestone quarry. Blast trials were carried out in cognisance of both drill and initiation burden while keeping all other parameters constant. Effect of front row burden was also extensively studied by keeping almost all other parameters constant. The results of the study reveal that there is substantial influence of front row burden on the vibration and air overpressure. The statistical analysis of vibration and air overpressure data with drilled burden and initiation burden gives significant evidence that the level of peak particle velocity of vibration (Vmax)) is reduced by reducing effective burden with modification of initiation. Data analysis carried out for air overpressure versus initiation burden shows that reducing effective burden with modification of initiation results in increasing the level of P. The study reveals a qualitative assessment of the influence of burden on the blast induced vibration and air overpressure. The study also recommends to modify the initiation pattern to reduce the effective burden in order to reduce the vibration, without disturbing the fragmentation.

Jan 1, 2004

By Carlos Campos Junior, Leonardo Soares Chaves, Raul Carretero Hoz, Renato Jacome Costa, Davi Bastos Martins de Oliveira

The Vale’s Serra Sul mine, also known as S11D project, is one of the world’s largest open pit iron ore mines, located in Brazil’s Amazon region. The mine produces around 90 Mt of high-quality iron ore annually. Its unique orebody enabled the S11D project to adopt a truckless mining system with In-Pit Crushing and Conveying (IPCCs) for ore exploitation and waste stripping. The IPCCs system requires crushing the waste, mainly composed by the jaspilite lithology, and is also conveyed to waste deposits several kilometers away from the mine. Due to Amazon’s environmental restrictions, the project was designed with preliminary geological knowledge, leading to the installation of primary crushers not designed for the hardest jaspilite, with uniaxial compressive strength (UCS) up to 500 MPa. This resulted in low waste crushing performance, affecting stripping ratio and threatening future production. A project was developed to improve the fragmentation of the jaspilite, allowing higher waste IPCC production, and reducing the risk to the production due to low performance of waste crushing and conveying. The first challenge was the independence of the geological and the geomechanical models, while only the geological model was considered in blast designs, the geomechanical model describes six waste groups of jaspilite classified according to their strength. A new geological model was then created to incorporate the geomechanical classification, allowing different blasting design according to the rock strength of the jaspilite. The blasting pattern on most compact jaspilite was reduced 27%, from 22m² to 16m² in 9 7/8” diameter holes, with a proposed theoretical reduction of 23% of the P80, from 326mm to 250mm. The second challenge was the implementation of the new design, as this pattern size and the high powder factor (2.9 kg/m3) were paradigms for such a large iron ore mine. The measured results have shown 25% reduction of the P80, the crushing rate was increased by 17% (230t/h), saving around $2.4 million annually in crushing and conveying system maintenance.

Jan 21, 2025

By C. Morel, P. Fredes, L. Rojas

This article presents a comprehensive study on the development and application of the specific module called "Exclusion Zone" created by Orica to determine blast evacuation exclusion zones. This module, integrated into the "SHOTPlus™ (blast design software)" software, has been used in the context of optimizing equipment evacuation exclusion zones in a northern Chile mine. The main objective has been to reduce the travel times of extraction equipment without compromising the safety of individuals. The module considers various factors such as the explosive charges used, stemming, sector topography, and detonation sequence to determine the rock projection generated by the blast. Furthermore, it utilizes information collected by drones and support tools such as Groundprobe and BlastVision™. The results obtained demonstrate that the use of this technology has allowed the optimization of blast evacuation distances in the northern Chile mine, generating significant economic benefits for the client.

Jan 1, 2024

By Sushil Bhandari, Amit Bhandari

In this paper, a case study is presented of a large global cement company using a cloud and mobile based platform across 17 of their mines consistently over a large number of users over a period of over two years. The use of a blast platform is detailed which include blast designs, blast data collection and the trends in terms of results.

Feb 1, 2020

By R. Jacob

Mining has been around for a long time, and new deposits are being discovered continually but are becoming more complex for processing and typically sulfide in nature. Most of the large easy deposits with simplified and cheaper to process oxide material have been mined or the deposits are locked up with legal or social issues and may never be mined. It is common to see the mines today being evaluated to mine have little in oxides and have a sulfide component to the deposit. This creates a problem with explosives being selected for the mine because ANFO could cause a reactive ground issue. When evaluating the cost component of mining for future mines, ANFO is the go-to selected bulk explosive because of the cost and effectiveness. More work needs to be done by projects evaluating costs by properly testing the ground and water conditions to match the correct bulk explosive for the ground conditions of the mine. This will prevent a possible safety hazard and the best result for the mine.

Feb 6, 2023

By J. Silva, T. Worsey

The Worsey-Silva equation determines the optimal row timing for the smallest fragmentation and allows fragmentation models to be adjusted due to row timing. The equation utilizes the concept of dynamic confinement to determine when the best time to fire the next row or sequence series would be if the smallest fragmentation is desired. Full-scale testing was conducted at an aggregate quarry in Ontario to support the theory and equation. The full-scale testing comprised six (6) blasts, two (2) different contractors, and three (3) different sequences. The test parameters were kept consistent, besides changing the timing between sequential charges to explore the timing sequence’s influences on fragmentation. From this research, the theory of dynamic confinement relating to row timing was discovered, and the equation to determine the optimal timing for the smallest fragmentation was derived. An equation to adjust fragmentation based on row timing was derived from the full-scale testing and literature review. The Worsey-Silva equation can be used with other fragmentation models as it takes the fragmentation results from the other models and adjusts them based on the row timing used. The paper explains the theory behind the equation, the research supporting the findings, and the developed Worsey-Silva equation for row timing

Jan 1, 2024

By Benjamin Cebrián, María Gil, David Flores

In many occasions during the Mining operation life, blasting engineers find different and controversial results of fragmentation, dilution or wall control for the same geotechnical domain and blast design (pattern and explosive charge). Most of the times, the difference between same blast designs is not measured, not controlled. Once a blast designed is defined, the most important part of the process after that is the implementation of every step of the blast on site. Almost nobody is measuring it, controlling it, but just controlling implementation is possible to relate blast design with results in a consistent way, to optimize the full process of D&B. Controlling implementation not only per event but also to check and change trends and decision-making is paramount for optimization and saving millions of extra costs every year. The lack of resources and the hardness to manage all the info created every day in a blast make this process very tough and difficult to maintain in long term. The use of new technologies on site and software that allows a best, more consistent and continuous control of blast implementation have been proved to be the key for optimizations and cost saving. This document shows the evolution of drilling and blast digitization process, savings and trends in a mine, using new technologies that creates business opportunities and general improvement of D&B process.