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By Dennis E. Mitchell

The need to develop and field explosive, pyrotechnic and propellant initiating systems that have high reliability and extraordinary safety requirements has led to the exploration and development of several materials and initiation systems at our laboratories. Our approach to initiating device development encompasses five main areas; energetic materials development , device physics, theoretical analysis and model development and experimental verifications

Jan 1, 1995

By C. Aimone-Martin, C. Dowding, M. Jern, J. Gjødvad

This article compares percentages of compliance for six national standards to demonstrate how these standards vary on-site in a real project. This, to the best of the authors' knowledge, has not been accomplished before. Different standards not only vary in allowable amplitudes of induced vibrations but also in how they are measured (transducer location, transducer orientation, frequency content of vibration, etc.). Thus it is not straightforward to compare the permissible values of induced vibrations with each other. This challenge of comparison is overcome in this project by instrumenting a structure with multiple transducers according to different national standards and comparing the degrees of compliance. Compared herein are compliance with standards used in United States of America, Germany, Great Britain, France, Austria, and Sweden. Averages of the percentage of compliance and ratios of measured vibration amplitudes for all six national standards are compared both in tabular and graphical form for 20 blasts at the Aitik mine northern Sweden. It is the largest open pit mine in Europe and blasts are atypically large with more than 1000 kg charge per hole and several hundred holes per blast, lasting 3-5 seconds. Results show that percentages of compliance can vary by as much as 2 to 75 % for these blasts at this structure. The overall project is a cooperative effort between EFEE (European Federation of Explosives Engineers) and ISEE (International Society of Explosives Engineers), supported by more than 17 persons from 8 different countries. At the present the experts are the four authors of the present paper and Dr. Robert Farenfield, Dr. Nathan Rouse, Douglas Rudenko, Brent Meins, Kenneth K. Eltschlager, Karin NorénCosgriff, Travis A. Davidsavor, Vitor Luconi Rosenhaim, Johannes Kutschera, Bernard Thierry, Thomas Moser, Cory Loukedis, and Keith Best. The project began with a literature study and a survey including an evaluation of the answers provided by members of EFEE. Results were presented at the ISEE conference in Denver 2020 as well as the EFEE conference in Helsinki in 2019 (Gjødvad & Jern, 2019; 2020). The second part of the project was initiated in May 2021 with installation of 7 seismographs from two different manufactures, 3 cracs gauges and 2 microphones on a building at the Aitik mine in northern Sweden. The third part of the project has moved to the United States. Two residential structures adjacent to quarries are being monitored in Michigan and Ohio. Installation and monitoring began in March 2023 and are expected to continue for 6 to 12 months. In addition to the objectives of phase two the 2023 study includes calculations of global wall strains from measured velocity time histories and measurement of response of existing cracks to vibratory and climatological effects

Jan 1, 2024

By Bethany Witter, Dyno Nobel

In the past decades, a technological explosion has caused generational shifts. First, millennials experienced a technological shift to computers and cellphones. Next, Generation Z experienced a shift to smart phones and social media. These two generations are immersed in technology and are accustomed to constant connectivity. How do the extractive and construction industries gain the interest of younger generations and integrate them into the industry?

Feb 1, 2020

By Dale Preece, Mike Stern, Steve Piercey, Ayman Tawadrous, GC Zhao

The McArthur River uranium mine in Saskatchewan, Canada is the world’s largest high-grade uranium mine. It has employed a freeze-wall system consisting of multiple freeze pipes to control the large quantities of water encountered during mining.

Jan 1, 2011

By J E. (Boet) Coetzee

SAFEX International, as the name suggests, is a global organisation, which has the fundamental objective of improving the safety of operations concerned with the manufacture, storage, transport, and use of commercial and military explosives and pyrotechnic products throughout the world. It is a nonprofit making organisation of manufacturers of explosives from all parts of the world, founded in 1954 with the aim of exchanging experiences within the explosives industry. Every third year SAFEX organises a Congress during which members present papers on selected themes and discuss reports of significant incidents that occurred since the previous Congress. Admission is for SAFEX members only, thereby creating a safe environment for discussing problems “within the family”. The XV Congress will celebrate the Association’s 50th anniversary in Geneva where it was founded. An overview of the Congress indicates its structure and covers aspects such as the training event, technical seminars and the themes for the plenary sessions and associated workshops. The paper also highlights the special event for the chief executives of member companies and the review of incidents that occurred in the industry since the last Congress. The Congress concludes with a social programme for delegates and their partners on the last day.

Jan 1, 2005

By Ron Lutz

In today’s world, production is the name of the game. We are all in business to make money. In the Quarrying and Mining industry the same holds true. The primary goal is to develop the best drilling and blasting program available to maintain uniform fragmentation to maximize production. Also we want to maintain drilling and blasting costs and minimize escalators. This paper is intended to discuss ways for all parties (quarry’s, blast service and drill companies) to attain this through understanding what can be done to help blasthole drilling and production. Blast designs and seminar’s emphasize the accuracy of drilling to produce better fragmentation. Blast design must also include basic concepts in the drilling process. The type of drill to be used for example whether it is a crawler or truck mount, top hammer or down the hole is important. Quarry operators have a role to play as well. They hold the key to the production of drilling. What the customer does or does not do has a direct effect financially to the drilling. The phrase of pay me now or pay me latter comes to mind. This paper will explore the detail of planning that is required by the quarry and/or blast service companies before a single hole is drilled. The drill must be able to meet the production need of the operation. The type of drill available and what can and cannot be done. The drill cost must be competitive. This paper will touch on comparison drill costs from 1967 to 1999.

Jan 1, 2000

By David Leidel, Beth Shimer, James Stuart

Periodically, the Institute of Makers of Explosives Safety Library Publications are reviewed, edited and updated to reflect recent technical developments, new commercial explosive products and new regulatory requirements. The rapid proliferation of electronic devices, particularly portable communication systems, inventory management devices, navigational aids, etc., required the revision of the IME Safety Library Publication 20, “Safety Guide for the Prevention of Radio Frequency Radiation Hazards in the Use of Commercial Electric Detonators”. The new edition of SLP-20 has been updated to correct alterations to U.S. frequency allocations and maximum transmitted power permitted and a discussion of communications and tracking systems required in underground mining by the Miner Act. Also, an entire section was added dedicated to safe distances from RF sources to the special type of resistorized electric detonators used in the upstream oil and gas industry on wellsites and an enlarged section describing the particular types of RF sources that the blaster may encounter, perhaps in construction blasting operations.

Jan 1, 2012

By Braden Lusk

The problem of predicting damage in densely developed areas due to incidental or malicious explosions is one of considerable importance to local, state, and federal governmental bodies. The difficulty of making such a prediction is confounded by the urban canyon phenomenon as the shock wave intensifies or rarefies depending upon the particular arrangement of buildings. The specific method detailed herein used a Computational Fluid Dynamics solver, ANSYS AUTODYN, to operate on Geographic Information Systems data, ArcGIS, which captured the geospatial relationship between the various buildings in downtown Oklahoma City, prior to the Murrah Building bombing. The model of Oklahoma City was first developed using the building footprints and elevations provided by the ArcGIS database. Due to the sheer size of the problem, the model was then subdivided into annular zones of increasing distance from the center of the blast. Each subsection was then solved using an Euler model in a cascading fashion with the output of the preceding model forming the input of the present model. To further reduce computational time, the size of the Euler nodes was increased at each stage as the section area increased. Due to the loss of precision in capturing peak pressure values when using larger size nodes, it was necessary to perform a transformation on the results using one dimensional wedge calculations with higher precision. The Murrah Building bombing event was an excellent case study due to its available ArcGIS data and the level of documentation of damage to surrounding structures due to the blast. The results from the staged CFD calculation were then used to develop a damage potential contour map. The documented incidents of damage in the area surrounding the Murrah building were then compared to the model generated damage potential contour map. Copyright ©

Jan 1, 2010

By Michael Wieland

The work principle from thermodynamics is used to model the shock and heave for explosives shot in rock or under water, with the latter compared to reported results. The work principle utilizes restrictions and constraints to yield a representative fit to the irreversible (natural) shooting process. The reduction of the internal energy of the reaction-zone yields the total expansion work (TXW), the resultant sum of the rock/water shock and heave. The restoration technique of forming a closed thermodynamic loop yields the reversible mechanical work (RMW) or the rock/water heave. The residual work that remains when RMW is subtracted from TXW yields the irreversible disorder work (IDW) or the un-dissipated (without loss) shock in the surrounding rock or water. The work principle renders an unequivocal relationship for the shock-loss factor, rather than the traditional roundabout formula for correcting the underwater gauge-shock of un-modeled explosives. There’s a novel heave-ratio factor that unquestionably rates the fit of results under comparison. Rock-shots are more complex in nature than underwater shots due to rock fracture and stratum rupture, though numerical resolution is worthwhile. The proposed rock-water-jelly (RWJ) model yields rough estimates, with rock-type results not wholly different from their underwater counterparts. Though reported underwater shots reveal shock and heave trends with respect to charge formulation ingredients, there are no such rock-shot results for comparison, since the relevant test measurements in rock remain difficult, if not intractable.

Jan 1, 2007

There remains considerable controversy in the industry regarding precision type detonators and where the end user can benefit from their use. In spite of the fact that electronic detonators and other prototypes were tested over one decade ago, explosive suppliers have hedged on full scale production for many reasons. Although some of the reasons were based on solid economics, others were strongly influenced by shear internal resistance within the corporate objectives, ultimate fear of market rejection, indecision as to what degree of precision was required and limited data on defining the real benefits to the end user.

Jan 1, 1992

By J. Schoonover, A. Moore

In the explosives industry, individuals face a multitude of hazards while working in mines, quarries, and construction sites. Safety becomes an ever-present driver as companies attempt to control costs, promote quality service and products, and grow business all while ensuring employees return home safely every day. One of the most challenging hazards that threatens the goal of absolute safety is flyrock. Ensuring that a blast does not result in rock leaving the blast area, thereby creating a danger for personnel in the vicinity, can be complicated due to the multitude of factors. Shot design, geology, operational procedures/techniques, explosive products, security plans, communication methods, and drilling practices can all adversely affect the safety of individuals helping execute a blast through an increased risk of flyrock. Flyrock can also pose a major threat to the public and other non-blasting personnel in proximity. Like many other industries encountering various challenging hazards, the explosives industry has recently adopted innovative technologies to help mitigate the risk of complex hazards such as flyrock. Specific applications of Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, employed in the explosives industry can help reduce the likelihood and severity of a flyrock incident. This paper explores a case study and theories of how the integration of drone technology within blast security plans, mine planning, blast design, design auditing, and blast area clearance procedures can help to decrease the risk of a flyrock event through the provision of data and information previously unavailable. Multiple opportunities exist during a blasting operation to gather data using drone technology. It is these data-gathering opportunities that can be leveraged to be maximally equipped for the mitigation of flyrock. Better data from drones can be sourced and used in security plans and clearance measures as well as utilized during mine planning and blast design. Increases in the quality and quantity of information during these crucial steps of blasting has proven to be an effective way to increase the peace of mind for explosive end users. This peace of mind, along with design flexibility and adherence to performance, is why the integration and utilization of drone technology is key for effective flyrock risk reduction

Jan 1, 2024

By Hairong Zeng, Shahram Tafazoli, Edmond Chow

Blast fragmentation is one of the main parameters for optimizing mineral processing, but reliable data is difficult to acquire, resulting in unpredictable performance and efficiency. Crusher and grinder circuits are designed to process specific rock size ranges. Oversized rocks require extra energy to reduce before feeding into the process, and undersized rocks indicate that the process is not used to its full extent. Blast design is the key to controlling the blast fragmentation, so the ability to accurately monitor the particle sizes is imperative.

Jan 1, 2011

By D. Johansson, C. San Miguel, U. Stenman, N. Petropoulos

Blasting is a commonly utilized method in civil engineering projects and mining operations. Ammonium nitrate-based (AN-based) explosives are the most efficient explosives today in terms of handling and performance. However, a side effect is the production of gases. The reduction of these gases plays an important role in the safety and environmental aspects in the working place. Therefore, optimizing the recipes of explosives is vital for minimizing the environmental impact and increasing performance. The aim of the project is to provide results and recommendations on the use of emulsion commercial explosives to support the Swedish mining industry and tunnel-contractors as well as the explosives manufactures. The approach was to test various recipes of civil emulsion explosives to investigate the generation of toxic fumes (CO, CO2, NO, NO2 and NOx) during their detonation. To further increase the knowledge of the influence of different additives, ammonium nitrate prills were added in various percentages. The experimental configuration consisted of magnetite mortar cylindrical specimens with a 50 mm borehole at their center, filled with emulsion explosive. Several tests with different emulsion compositions regarding ammonium nitrate additives (10%, 20%, 25%, 30% and 35%) were carried out in a blasting chamber. The measurement equipment was composed of a flue gas analyzer. The instrument was meticulously cleaned after every test, as well as before and during the tests due to condensation (high humidity and dust) at the inlet of the instrument. The emulsion was manually sensitized with microballons and pumped into the cylinders to ensure lack of bubbles, which could introduce inhomogeneities. The acquired gas concentration data was complemented with temperature, humidity, and VoD measurements. The results showed a linear increase of nitrogen gases as the percentage of ammonium nitrate prills increased. On the other hand, carbon gases had a relatively low coefficient of determination. The VoD data showed a behavior that can be described with a simple quadratic equation.

Jan 1, 2024

By Pavel A. Torres, Darwin Torres, Sandro Huaman

Given the limited efficiency of blast-induced ground vibrations prediction empirical models, due to the complex geological system from a Peruvian mine. An artificial neural network was built in order to get better results. More accurate and precise predictions allowed the generation of blasting domains for future designs and decision making.

Feb 1, 2020

By Winfried Rosenstock

AEBT has been available for a couple of years and is successfully applied in Australia. Up to now it was mainly used in coal surface mining at the Australian East- Coast. Presently, the proved results reach ~ 50 % reduction of Drilling & Blasting costs and a productivity increase of between 10 and 20 %. In 2003 it was for the first time used in surface metal-mining. The mine features for the time being an extremely difficult geological environment and had above to be carried out in the transition level waste/ore. Reductions of wall control, powder factor and vibrations were the main target.

Jan 1, 2004

By C. Zuniga, S. Combrinck, C. Peters

Agnico Eagle Gold have partnered with Enaex Australia at their Fosterville gold mine to leverage a combination of drill and blast technologies to optimise underground development mining. The mine is the first site globally to collaboratively develop and trial Enaex SWIFT electronic development detonators, which utilise a novel approach to the user interface, simplifying implementation and enabling the benefits of electronic initiation without the complexity of a conventional system. This has been combined with the use of a Sandvik 422i smart jumbo, and the Enaex underground emulsion charging unit with the capability to tailor the delivery of explosives as required and report on a hole-by-hole basis. The combination of these technologies enables full engineering oversight of the development cycle, in turn enabling optimisation of this process in a historically conservative application. The methodology for leveraging these technologies is to bore a controlled and defined blast pattern through using a smart jumbo, load the blast holes utilising lace loading to deliver a desired quantity of ammonium nitrate emulsion per hole, with the ability to reduce chargeweight for perimeter control, and utilising Enaex SWIFT electronic detonators with flexible template type pre-defined delays to initiate the blast holes. Subsequent to firing and excavation the performance of the blast in fragmentation, advance efficiency, and overbreak and underbreak is measured and reviewed. This is then used to optimise the development cycle and apply to other parts of the mine.

Feb 6, 2023

By Tom Pfitzer, Alice Correa, Meredith Hardwick

The past decade has brought significant changes in the use of risk-based criteria for safety within the U.S. Department of Defense. The Range Commanders Council (RCC) chartered a working group to develop and define risk acceptance criteria for protecting the general public and mission essential personnel from debris from launch ranges. This working group has continued to develop and update RCC Standard 321 as the needs of the ranges and range users have evolved. A revision to RCC Standard 321 is near finalization and will include casualty criteria, guidelines for assessing risks due to other flight hazards in addition to inert debris, and an overall risk management process for range safety. This paper reports on work in progress and includes several precedents which may prove important to the explosives safety community.

Jan 1, 2007

By Mark Bauckman

Discussion Topics • Market Needs • Technology Developments & Best Practices • Industry & Government Developments • Future Possibilities & Your Role

Jan 1, 2006

By Roger Holmberg, Donald Jonson

The Swedish Standard SS 460 48 66, “Vibration and shock - guidance levels for blasting induced vibration limits”, is based on more than 50 years of experience from blasting close to structures and tunnels. The Swedish Standard gives a method for calculation of guidance values for different types of buildings and ground condition under the building. This is done for every building and structure within a predetermined zone. The guidance levels are for the peak particle velocity monitored in vertical direction. The standard is valid for all kinds of blasting project (tunnelling, quarrying, mining etc.) The guidance levels neither take in to consideration discomfort for people inside the building or structure nor vibration sensitive equipment inside the structure. The paper also presents the Swedish Standard SS 02521 “Vibration and shock - Blast induced airborne shock wave - Guidance levels for buildings”.

Jan 1, 2005

By Greg Quinn

After a long week of work in Colorado Springs this past July, I was looking forward to flying home to start a long anticipated family vacation. As I grabbed my seat on the plane, a man sitting next to me innocently inquired, to the row as a whole and not to me in particular, “I wonder what the weather will be like in Phoenix”? To most people, this is a common (maybe the most common) topic of casual conversation. To a meteorologist that just dealt with six thunderstorm delays at a major golf event over 4 days, well, lets just say the smirk on my face said it all. After giving my flight mate a detailed forecast and a short explanation on why I would know such information, I sensed, correctly, the inevitable follow up question was coming. “Why would you need a meteorologist at a golf tournament?”

Jan 1, 2012