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By Alan B. Richards, Aleks Todoroski

The undesirable effects of blasting fumes can be controlled by minimising the amount of fume created, and by avoiding the movement of the fume plume to sensitive locations. Substantial progress has been made by the blasting industry to reduce the amount of fume typically created by blasting, but at this time no specific blast can be guaranteed to be ‘fume free’.

Jan 1, 2017

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 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 Türker Hüdaverdi, Özge Akyildiz

"Efficiency of blast operations depends on fragmentation, overbreak, muckpile profile anddisplacement, vibration, airblast, flyrock and damage to wall or slope stability. To provide all these conditions at the optimal level, determination of rock mass properties (in-situ block size, joint spacing and orientation) is the very first step during design stage of rock blasting. Image analysis software is used not only to determine the fragmentation level of muckpile but also to characterize the bench face. In this study, an image analysis software was used to determine apparent block size of bench face and to measure blast fragmentation of muckpile. The source of errors and the vital points to be taken into consideration were explained for bench face characterization andfragmentation measurement. Since it provides much better results than previous techniques and it is not intrusive to production process, image analysis technique is considered as one of the most efficient and preferred way for fragmentation analysis. Besides these advantages, there are some weak points of image analysis software. Lighting is one of the most important factors for photographs captured for in-situ block size analysis and fragmentation analysis. Lighting determines shadow formation. In an ideal image, particles are clearly delineated by soft shadows. If shadows are too strong (dark), analysis suffers. Appropriate scale should be replaced onto blast muckpile during site measurements. The location of the scale in image affects the results of analysis. Also, the densityand orientation of discontinuities should be considered during application of image analysis technique to characterize bench faces. In this study, image analysis software was applied in thesandstone, limestone quarries of Istanbul region and an open pit boron mine. All image analysis, evaluations and results were made based on the site measurements."

Jan 1, 2017

By Radhe Krishna, Mutale William Chanda, Timothy Mwale

Blasting as a process is the emplacement of industrial explosives into blast holes suitably located to a free surface and detonated. Every blast hole containing a certain amount of explosive charge undergoes impulsive loading when detonated and results in the dynamic transfer of a powerful shock wave to the surrounding rock. It is the shock wave that brings about rock breakage when the tensile stress produced upon reflecting from the change in material density or free face overcomes that of rock material tensile strength. However, this shock wave comes along with unwanted destructive consequences such as damage to remaining rock, ground vibration, noise and fly rock. The above mentioned consequences pose a great threat to the Community of Wusakile, Kitwe as Mopani Copper Mines Plc wishes to increase its production by expanding the pit towards the community that lies within 150 m (164 yd) from the pit rim. As a requirement from the Zambia Environmental Management Agency (ZEMA), all blasting operations close to the community must maintain at least below the maximum vibration threshold of 10 mm/s (0.3937 in/s) PPV-Peak Particle Velocity or else risk closure of the mine (AMC,2009). In order to satisfy the above statement, a good understanding of explosives is required. This paper therefore presents the phenomenology of rock breakage by explosives with much emphasis on electronic blasting and how best this process can be controlled in densely populated communities. Factors affecting maximum projection distance such as, size of the fragment, shape of the fragment, angle of projection, the state of confinement of an explosive charge, were also studied. In addition, design faults, deviation in implementation and unforeseen geological conditions were also considered. The paper discusses the above facts based on research.

Jan 1, 2015

By Tyler Rockley, Carla Reyes

Autonomous fragmentation measurement systems designed for shovels have been in operation for nearly two decades, however fragmentation systems capable of performing in the dynamic conditions of the front-end loaders (FEL) were only recently introduced to the market. This paper presents an in-depth evaluation of an automated digital fragmentation measurement system specifically designed to perform under the dynamic operational conditions of the FEL in two of Teck’s mine sites. As early adopters of this novel application, Teck embarked on a Proof-of-Concept (PoC) trial phase, defining a set of key performance indicators (KPIs) to qualify the performance of the digital solution in tough mining operating environments. The KPIs focused primarily on the hardware robustness, quality of image and segmentation, both day and night, availability of the system and sample ratio. The benefits expected from using this technology include increasing the safety of the current fragmentation measurement process, improving the quality of the analysis, increasing the sample representativeness, and using the attributes of the system to create an oversize detection alert to inform the loading operation process. A critical part of the evaluation was verifying the system’s effectiveness on the particle segmentation algorithm as this element often gets overlooked, especially when dealing with the large number of samples autonomous systems can generate; minor misclassifications due to inadequate segmentation are often dismissed as they might not be statistically significant, however systematic misclassifications can cause unacceptable deviation in the data and limit the intended application of the technology. The system’s performance was further validated through several tests that involved identifying objects of known sizes to ensure the reliability on the consistency of the particles’ segmentation.

Jan 21, 2025

By Robert Jacob Cefalo

In 2019, the Bingham Canyon Mine, owned by Rio Tinto Kennecott Utah Copper Company, mined through the active underground that dewaters the pit. The active underground required the limitation of vibrations to avoid catastrophic damage or damage that would require work to the shotcrete and additional roof support. The surface design of the current sector was mined next to and through portions of the active underground.

Feb 1, 2020

By Anthony Konya, Calvin J. Konya

The publication, RI8507, from the U.S. Bureau of Mines established an envelope equation that related scaled-distance to peak particle velocity in an attempt to predict ground vibration in the design phase of a blast. This has been further modified by Oriard, Dupont, Konya & Konya, and others to develop more refined prediction models for specific situations to obtain better predictions. While these equations can be an ideal starting point for a greenfield blasting project or a project with no given information, these equations can have errors.

Jan 1, 2018

By Stephen Mansfield

Analysing how accurately a blast design is implemented is one of the cornerstones of a successful operation, and critical for mine optimisation. This paper presents a concept that involves the collection and analysis of data for the five stages through which a blast transitions, from budget through to implementation.

Feb 1, 2020

By Bill Rose, Alan Foster

This paper will outline blasting as undertaken at the Flour Mill project in the Georgetown area of Washington, D.C. It will discuss the vibration and blasting problems found in blasting in high risk and highly populated areas, and the day to day methods used to minimize damage potential and still maintain adequate fragmentation.

Jan 1, 1979

By Bilegt Batbold, Bayu Saputra, Chris Batten

The ability to fire multiple blasts simultaneously can provide significant benefits to any open pit mining operation. Reduced blast-related downtime by reducing blast events can increase equipment utilization and maximize material movement. Significant sequencing benefits can also be delivered, associated with reduced equipment relocation. This paper describes the work completed in partnership between Orica and Oyu Tolgoi to successfully demonstrate that combined production-trim and midsplit blasting could be implemented successfully while successfully managing the risk of increased damage to the final walls. The paper details the methodology used to assess key performance measures linked to final wall damage and compares the performance between the following blasting methods. • Free face trim blasting vs. combined production-trim blasting • Presplit blasting vs. midsplit blasting. The results of the initial trial blasts are presented, along with the method agreed by the key site stakeholders for ongoing application. The method used to keep the risk of final wall damage to an acceptable level is explained, along with the benefits delivered to Oyu Tolgoi operations associated with the initial 12 months of application.

Jan 21, 2025

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 Cam Grundstrom

The Ok Tedi Mine is a large open pit copper and gold mine located in a remote section of the Western Province, Papua New Guinea, with an annual rainfall of over 10 metres. Ok Tedi mines an average of 205,000 tonnes per day. A strong working co-operation between the mine operator (Ok Tedi Mining Limited) and the explosives contractor (ICI Explosives Asia / Pacific) has led to progressive development of bulk emulsion formulations to meet site-specific needs, continued improvement to blasting applications, and competency based training programs for the national blast crew.

Jan 1, 1997

By Harnish Miller, Scott G. Giltner

One of the concerns with locating radioactive waste storage sites in salt deposits is how to permanently seal the underground storage areas once they have reached their storage capacity. The compaction of salt using explosives has been identified as a potential method of producing permanent seals in both entryways and shafts to storage areas. This paper describes the test procedure and results of a preliminary investigation to determine the feasibility of utilizing explosives in the compaction of salt. Three simple tests were carried out to measure the degree to which loose salt could be compacted.

Jan 1, 1996

By Zhou Jiahan Wang Feng

This paper introduces the mechanism and the operating process of dike building by silt squeezing blasting. DBSSB (dike building by silt squeezing blasting) has the following advantages: shorter construction period (the construction period is decided only by the speed of rock materials filling)greater consolidation of the body of the dike, more structural stability, smaller settlement. Therefore by conventional standards the same dike can be designed with a smaller cross section than other construction methods, and at a reduced cost when enough rock materials can be provided in site.

Jan 1, 2006

By NA NA

Copyright © 2020 International Society of Explosives Engineers

Feb 1, 2020

By J. D. Aubertin

Rock blasting is a complex engineering process that requires in-depth knowledge of operations and geomechanical conditions. Acknowledged design precepts are based on cratering behavior associated with stiff hard rock masses. Other cratering mechanisms may however arise under certain geomechanical conditions such as extremely fractured rock masses, or with soft rocks such as rock salt and potash. The burden dimension also plays an important role in the prevalent cratering mechanisms of a given blasting condition. The present article investigates the variability of cratering profiles and geometrical trends based on characteristic geomechanical differentiation and considering the influence of burden. The differences in observable mechanisms are examined through small and large-scale single hole blast (SHB) tests. SHB tests involve a series of individual shots blasted parallel or sub-parallel to an open face. The burden dimension is varied to obtain burden dependent characteristic trends. The breakout shape is represented by a crater model in the form of a power law equation capable of describing prismatic, concave and convex cratering. The formulation comprises two reference index parameters that can describe the geometrical and geomechanical conditions. SHB test campaigns conducted in rock salt, limestone, massive amphibolite, pinolite, and grout blocks are compiled in quantitative manner to demonstrate the influence of geomechanics on cratering profiles. The observed trends are corroborated through numerical modelling carried on Finite Element Model (FEM) LS Dyna to investigate the prevalence of specific cratering mechanisms. A series of SHB tests at large and small burden values are also used to showcase the influence of geometry on the prevalent cratering mechanism and the resulting crater

Jan 1, 2024

By Fred Baldassare, Marcia Harris, Kenneth K. Eltschlager

Surface mine blasting was recently investigated as a potential source of high concentrations of stray gases found in nearby residences of western Pennsylvania. In one incident carbon monoxide was detected in a home and in the other, high concentrations of carbon dioxide were found in a home. Both carbon monoxide and carbon dioxide are by-products of blasting. However, other potential sources of these gases may also exist in a residential setting. In each case, gas chromatography (GC) and carbon isotopic analyses were used to define atmospheric concentrations inside the homes, and to determine the source of a stray gas. Molecular and isotopic analyses provide geochemical evidence as to the origin and source of the stray gas. This paper discusses elements of a stray gas investigation and the analyses necessary to identify the source of a stray gas.

Jan 1, 2004

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