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By Eduardo Lozano, Vilem Petr

The use of explosives bring countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition or avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation. The goal of this paper is to provide a solution against the hazards which unfortunately accompany the use of explosives. For this reason, a blast shield is specifically designed and tested for protecting personnel against these unpredictable effects. This document will develop a complete analysis answering the following questions: what are the potential hazards from an air blast; what are their effects; and how can we be protected against them. In order to answer these questions, theoretical, analytical, and numerical calculations are performed. Finally, a full blast shield prototype is tested under blasting conditions proving its effectiveness as a safety device while explosives are used.

Jan 1, 2015

By Chris Breeds, Larry Leone, Jerry Wallace

One of the Authors was recently retained to provide a professional engineering analysis of the potential impacts from underwater blasts used to enlarge intake tunnels at the Cheesman Dam near Denver in Colorado and to design Blast Protection Bags that could be installed in each tunnel to protect the 100- year old downstream valve structures.

Jan 1, 2012

By S. Gajardo, E. Valdés Guerra

Together with Sociedad Punta del Cobre S.A. (Pucobre) and Orica, we are carrying out a study of alternatives for methodology of excavation in Slot Up Raises from actually built with Blind Hole (BH) to drilling and blasting (DB) methodology. The study is part of the permanent search for innovation, the use of technology and the reduction of mine operation costs. This application aims to optimize the Sub Level Stoping method, which has historically been exploited at Pucobre. Using a new variant of the method “Open Stoping”, through the initial development of ascending blind raises using a pilot drilling of a bore hole, with the objective of eliminating the upper level in order to excavate the free face opening. This industrial test aims to replace the mechanized BH Up Raise of 1.5m (4.9 ft.) in diameter and 30m (98.4 ft.) high, with a Up Slot Raise considering two separate blasting events, using different technological enablers, as detailed below: accuracy drilling with relief holes of 254mm (10 in.) diameter, high viscosity bulk emulsion, wireless initiation system and high-strength injectable bulk resin. Considering the importance of the success of this application, a DB diagram was defined to allow the opening of the up raise in two blasting events, separated by intermediate stemming deck located at the same level at a height of 15m (49.2 ft.) from the collar, using high-strength injectable resin. The first blasting event considers the first section from the collar to the first 15m (49.2 ft.), using wired electronic initiation that is detonated on the first day. A second event blasts the section from 16.5 to 30m (54.1 to 98.4 ft.), using a wireless initiation system, as, it has no physical connection, is blasted on the second day after the extraction of the material resulting from the first event. For greater precision, the design of the explosive charge configuration and initiation sequence is made, adjusted to the measurements of trajectory deviations of the actual ground drilling and is also considered for the control of the explosive charge configuration with high viscosity bulk emulsion. This application improves the profitability of the mining business by generating savings through the change of Blind Hole methodology, estimating a savings of more than 75% per Up Slot Raise

Jan 1, 2024

By Iván E, Alex Araya Jofre, Jean Guiroux Toro, Eduardo Valdés Guerra

Currently, it is important for companies to have controlled mining operations and adhere to production schedules. To achieve this, one of the key factors is maintaining high reliability in the P&T process, primarily the opening of ore stope, which could be delayed due to any unplanned or uncontrolled problem. These ore stope opening processes, whose main activity is generating free face, are a very important pillar for future mine planning. The possibility of ensuring their opening brings a series of downstream benefits: safety, economics, productivity, and compliance and adherence to plans. The process under discussion consists of developing free faces in a single blasting event. This will help us leverage greater reliability for overall production operation plans, reduce construction times, and open up opportunities for downstream improvements in the production process, considering technical factors in P&T designs. This study presents a developed methodology and shows the results of its implementation in ten (18) single-event free face blasts. The analysis includes cavity geometry, geology, rock qualities, drilling deviations, and the blasting strategy implemented for each event. The methodology used considered material fluffing processes, the actual drilling trajectory, the initiation sequence, QA/QC during explosive loading, monitoring instrumentation (vibrations), and VOD recording, among others. As a result, out of a total of 18 free-face events blasts in a single event, 16 were successful and two achieved 90% efficiency, reducing the stope's production start-up time by 50% compared to current operations. By implementing free face blasting in a single event, there are savings in operating costs, increased productivity of the mining equipment, and improved adherence to production plans. For applications with greater heights of free faces, where blasting cannot be carried out in a single event, we should consider performing them in two stages using wireless detonators already available on the market for mining operations.

Jan 26, 2026

By Adrian Moore, Alan Richards

"It has been common practice to set blast vibration limits for structures using an “observational”approach whereby limits are set at a level based on observations of damage, or the lack ofdamage, combined with a tendency to further reduce the permitted level due to uncertainty. Suchan observational approach was used in the USBM RI 8507 to produce the frequency dependent‘Safe Levels of Blasting Vibration for Houses’ which has become a universal Standard for overthirty years."

Jan 1, 2013

By Kenneth Faroni, Catherine Aimone-Martin, Thomas Gelormino

A blasting improvement program began in 1985 at two traprock quarries in Connecticut to reduce the levels of ground motions and airblast measured at residential structures surrounding the operations. The quarries are situated within town limits, adjacent to a number of historical and other structures. Although blasting vibration amplitudes were found to be far below those that could produce cosmetic defects in structures, they were perceived to be the cause of structural defects observed by homeowners. Based on a comprehensive * review of blasting practices in place during1985, an extensive vibration monitoring program was implemented. The initial study included the instrumentation of selected residential structures to record and analyze strains imposed within structures from quarry blasting, environmental changes, and from daily household activities. A comparison of the results was made with the results reported by the U.S. Bureau of Mines in 1980. The highest strain imposed in drywall from blasting (13 J_I strain) was 12% and 1% of the highest strain levels recorded for normal household activities and temperature changes, respectively. The present philosophy in production blasting is to attempt to keep vibration amplitudes as low as practical by implementing state-of-art blasting control techniques. Currently, blasting seismographs are placed in a circular manner around each quarry, providing production blast vibration records for 360 degrees of coverage at distances of 2500 to 4000 ft. from blasting operations. Seismograph and production blast records are analyzed each year and become part of a Blasting Improvement Plan submitted to the local zoning commission as part of the annual operating permit process. This paper summarizes the results of previous vibration monitoring programs and outlines the modifications made to blasting practices to minimize the levels of ground motions and airblasts. The public relations efforts and standard corporate procedures used by company personnel to address all blast related complaints and alleged damage claims since 1985 are also discussed.

Jan 1, 2000

By Norman Paley, Zachary Pickett

The Red Dog Mine is a high-grade zinc-lead mine located in northwest Alaska which began operations in November 1989. In June 2014 the upper half of a charge in a trim shot in the Aqqaluk pit deflagrated. No other holes in the area were observed to react and the remainder of the pattern was shot without incident. This was the only known case of a deflagration in the 25 years of operations. As part of the investigation into the cause of this incident rock samples were obtained from the area of this hole and from other areas in this pit.

Feb 1, 2020

By P. Ravanal, J. Blazquez, F. Ortega, P. Couceiro, J. Navarro

Massive blasting technique is an interesting alternative to optimize mining’s performance by enhancing digging rates and overall operation’s activities, especially when a reduced operational bench width is available. The exploitation of a huge bench through multiple blasts would mean a potential reduction in productivity and higher operational difficulties. In such hard circumstances, combined with complex geotechnical conditions, a full ground vibration analysis for near and far field vibrations are required in order to safely design and conduct the blast. In this paper, a comprehensive case study will be discussed to show how the application of massive blasting techniques was safely implemented in very complex geotechnical conditions. The proposed solution was based on performing a full ground vibration study to optimize blast design parameters, such as charging and timing, in order to fire the complete bench blast in a single shooting event, without compromising the slope stability. Thus, a massive blast with an approximate tonnage of 6.0Mt was successfully designed and blasted, attending all safety and stability criteria defined by the geotechnical and drilling and blasting departments of Minera Escondida.

Jan 1, 2024

By Kenneth Eltschlager

Blasting represents the highest risk of any surface coal mining activity that could result in injury and/or property damage off the permit area. In addition, blasting related issues e.g. flyrock, vibrations, air blast, etc., are responsible for a large percentage of citizen complaints. Thorough and consistent regulation of individuals certified to conduct blasting by the Office of Surface Mining Reclamation and Enforcement in Federal Program states and on Indian Lands under Federal jurisdiction is vital, as it serves to: facilitate coal production to meet the nation’s energy needs; protect people and property on and adjacent to Federal mining permits; form a basis for states to grant reciprocity certificates to Federal blasters; and be a positive example to primacy states. OSM issues Federal blaster certificates for blasting on Federal surface coal mine permits. The certification program includes experience, training and testing components similar to many of the states. But where a state program may focus on the specific blasting applications within its boundary, the OSM certificate requires a very diverse test to cover all potential blasting applications and products across the nation. Therefore, the Federal certificate is a good surface mining credential for blasters anywhere in the United States.

Jan 1, 2010

By Alan Diaz Butron, Eng. Thierry Bernard

"In tunnel blasting the most challenging objective is definitively obtaining the maximum advanceassociated to a minimum overbreak. Achieving 100% of advance with no overbreak is the targetchallenge by Chavimochic Consortium. Chavimochic Special Project is an irrigation system that extends throughout much of the coast of the La Libertad Region, on the north coast of Peru. In 2012, it began management for construction of the third and last stage of CHAVIMOCHIC to irrigate lands of Chicama Valley, North of Trujillo. This project of 13 Km (8 mi) of various tunnels, it's a combination of technology and daily optimization by experienced people, which allow to accomplish the objective. Achieving this advance with no overbreak provide a huge saving on time. This paper describes the method, technology used, and the results obtained on more than 600 blasts done with conventional initiation system on the first 3 km (1.86 mi)."

Jan 1, 2017

By Stephen Mansfield, Johannes Schoeman

In August 2006 a technical alliance was formed between Orica Mining Services and Century Mine to provide blasting solutions. The alliance is in the form of a Rock to Specification (R2S™) service, one of Orica’s Blast Based Services (BBS™). The ultimate goal was to facilitate the rapid expansion of material movement from 26 to 41M m3 (34 to 53M yd3) per annum while maintaining a reliable ore supply to the mill.

Jan 1, 2010

By Langdon T. Mitchell, Karl Ingmarsson

The title is not referring to jewelry; nor is it about diamond core drilling. This article is instead about an emerging application for diamonds, hard rock percussive drilling with diamond drill bits. Diamond’s outstanding wear resistance has long been taken advantage of in core drilling. However, until now diamond has been less successful in hard rock production drilling in the mining and quarry industry.

Jan 1, 1999

By D. Fry, S. Hunsaker

Ammonium nitrate in explosives and sulfides in reactive ground have the potential to react at ambient and elevated temperatures resulting in premature detonations. The Australasian Explosives Industry Safety Group (AEISG) published, in 2006, a Code of Practice1 for elevated temperature and reactive ground. This paper reviews the chemistry, general reactivity of various ground types, elevated temperature hazards, and testing protocols contained in the code, that are industry best practices for managing ammonium nitrate-based explosives in elevated temperature and reactive ground conditions. In addition to reviewing the 5th edition AEISG Code of Practice, data is presented validating the recommended sampling guidelines within the code. Dyno Nobel has been screening reactive ground samples and performing sleep time testing since the code of practice was first released. Test results demonstrate the effects of samples that are allowed to oxidize before testing and are shown to be subsequently less reactive and not representative of the actual hazards facing mining blasting operations. Results also show that for a given reactive ground sample, reaction times decrease with increasing temperature. Data also quantify the delay in reaction time given by inhibited products. These results emphasize the importance of proper sampling and preparation of samples to accurately characterize elevated temperature and reactive ground hazards. They also demonstrate the efficacy of inhibited products in managing these hazards

Jan 1, 2024

By Tom Treleaven

The success of any blast is dependent on the accuracy of the blast design and the field controls used on the shot. This point cannot be over emphasized because when the geometry is not measured and/or field controls are not properly implemented, it can often have devastating effects on the final blast results. Thus drilling accuracy, tiont row burden control, explosive confinement, energy distribution, explosive selection, timing and structural geology become critical parameters in the design of successful blasts. Understanding the actual dynamics of the blast and why certain results were achieved is the fast step in optimizing a blast design. As stated by R. Frank Chiappetta, “Of all the blast monitoring systems available today, high speed videography still remains as the best stand alone instrumentation system for blast diagnostics.” Over the past years I have analyzed hundreds of blasts using either high-speed lowcams (500 frames per second) cameras or standard digital (30 frames per second). These analyses confirm, without a doubt, that shot geometry, in combination with structural geology, is the most important factor in overall blast results. Drilling accuracy is the single most important component in efficient blasting. Having equal mass associated with an equivalent energy is the basis in which blasts are designed. When drilling inaccuracy or borehole deviation occurs, not only is the energy unevenly distributed, but the basis of all design calculations becomes invalid. Over the past several years, quarry and mining operations have employed the use of boretracking measuring devices to measure borehole deviation and hole toe locations. In cases of operations using top hammer drills, it was discovered that the amount of deviation was significant and far greater than they believed they had. Set up error, improper drilling techniques and bit wear were some of the contributing factors. Through video anaysis of boretracked blasts, blast results were directly linked to drilling ..accuracy. The comparisons here took into account blast design, energy factors and hole sequencing.

Jan 1, 2000

By B. Winterberg, C. Lewis, M. Starkel, C. Johnson

Non-electric systems, specifically shock tube, have become the pyrotechnic detonator of choice over electric due to their safety regarding accidental initiation from stray radio signals. Typically, the best practice when hooking up shock tube systems is to have direct contact to ensure initiation. When gaps are introduced to the explosives chain, there is potential for detonation to come to a halt. It is understood that direct coupling is required between the various elements in the explosive chain to ensure detonation. This holds true whether tying in non-electric detonators, loading holes in a mining related blast, or priming a block of C-4. Poor contact and gaps in the explosives chain can lead to detonators firing out sequence, leading to increased vibration, air overpressure, and other undesirable blast results. Furthering work conducted in previous experimentation, a new study was conducted at the Missouri University of Science and Technology’s Experimental Mine in Rolla, Missouri to observe the initiation potential of an air gap and fragmentation on non-electric shock tube. A series of small test blasts were conducted using 50 grain detonating cord and fragments from a blasting cap to initiate a non-electric shock tube across an air gap of varying distances. The data collected in the high-speed imagery was used to analyze the velocity of the pressure fronts and blasting cap fragments used to initiate non-electric shock tubes across an air gap. It was found that the shock tube was sensitive to 50 grain det cord at a 5cm (1.97in) distance while parallel and 10cm (3.94in) when perpendicular as well as sensitive to frag from the electric cap out to 2.4m (7.87ft).

Jan 1, 2024

By TTE-Europe GmbH

A few years ago, the term Track & Trace for explosives was only known in Europe and Brazil at most; the introduction of this technology is experiencing an undreamt-of boom worldwide. More and more countries are enacting legislation to introduce Track & Trace of explosives and follow Europe and Brazil on this path. At present, the world's leading manufacturers are already using such solutions, are in the process of implementing them, or are in the planning process. However, based on the experience gained in Europe, there are outstanding challenges for all manufacturers. These are questions of compliance, logistics, distribution, and, of course, especially, the necessary adaptation of the production environment. However, this development involves considerable effort on the part of the manufacturers. New devices for marking the explosives and digitally recording the data are integrated into the production process. This should be done as cost-effectively as possible, without restricting production capacity and speed, and with as few process changes as possible. This paper uses real-life customer experiences examples to explain paths from project design to real implementation. Lessons learned from the experience of European explosives manufacturers are presented, missteps are described, and solutions are identified. Individual steps along this path are explained, and solutions are told to avoid pitfalls and bottlenecks. Finally, it refers to the risk analysis and concrete examples in implementing the planning into production. Methods of marking various explosives are shown, and the use of Track & Trace to solve logistics tasks in picking and shipping explosives, including the data exchange with ERP (Enterprise Resource Planning) systems.

Jan 26, 2026

By Marco Antonio Falquete

Conventional detonators and blasting caps make use, as igniters, of flame-shock-, andfriction-sensitive primary explosives, such as lead azide, lead styphnate, mercury fulminate, etc, most of them severe toxic and environmental contaminants. Sensitivity of primary explosives is one of the main causes of injuries and fatalities in explosives industry and in field applications. Intense research for a reliable, safe, and environmental-friendly non-primary-explosives detonator was conducted by the industry in the last years. A new detonator is presented, containing no primary explosive, employing only environmental-friendly substances while keeping reliability of performance. A series of performance tests is executed in prototypes of different output energies, including initiation by flame, shock tube, thermo tube (IBQ’s proprietary spark-generating tube, presented at 2005 ISEE Conference), energy transfer reliability, and extreme environmental conditions (according to MIL-STD 331B, test C1 standards). Results are compared, when pertinent, with standard blasting caps of different energy outputs, and with standard primary explosives.

Jan 1, 2007

By Bonifacio Degay, Mike Lovitt

PT Freeport Indonesia is a block cave mine that now utilizes an advanced undercut method to set up the min in the Deep Ore Zone (DOZ). In this method a slice of rock (undercut) is broken such that it sits on top of the drawbell level. The drawbells are developed to channel the broken ore into the extraction level and to enable the caving orebody to be drawn out in an even and controlled manner. These drawbells are difficult to form due to the small amount of void that can be developed in the low strength rock before firing. Starting with two rises of 2m square, the void ratio for the entire drawbell around 6%, which would normally result in a frozen and unproductive blast. Orica -Mining Services have worked with PT Freeport in a collaborative effort to find a solution to the mining problem. With excellent control of timing of the blasting it is possible to get fluid flow of blasted rock out of the draw points such that more void can be made available for blasting the remaining parts of the drawbell. The i-konTM electronic blasting system gives the exacting control of timing within the blast to achieve this Dynamic Void Generation (DVG). The solution stops the need to charge close to brows in the drawbells and reduces the cost and time related to developing initial blast voidage. This paper identifies the results of the trials including design, photographic evidence and vibration analysis. The flexibility and accurate timing of this electronic blasting system has enabled single hole initiation rather than 4 or more holes being initiated together, thereby reducing the damaging vibrations to the extraction level.

Jan 1, 2004

By Patrick D. McLaughlin, C Fordham

"The project outlined in the accompanying paper was to densify beach sands on the pond side ofa tailings dyke to the strength required for future dyke construction, This was to be achievedthrough the detonation of relatively small explosive charges in the sand to cause settlement intoa denser state."

Jan 1, 1992

By Joshua Hoffman, Braden Lusk, David McLane, John Rathbun

The dynamics of explosive detonations are understood; however recreating a real-world, to-scale scenario is costly. The use of a shock-tunnel allows testing to be done on a smaller scale, with the simulated effect of a large explosion. Analyzing explosive waveforms using this method can greatly reduce cost in testing blast-resistant products, such as anti-terrorism devices, mine safety products, and military equipment. The purpose of this project is to better the understanding of how the waveform dynamics of an explosive detonated within a shock-tunnel differ from those in an open-air arena test.

Jan 1, 2011