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By Marcia Harris, Richard Mainiero, Michael Sapko

Since 1988, there have been 17 documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through ground strata into occupied enclosed spaces as a result of proximate trench blasting or surface mine blasting. These incidents resulted in 39 suspected or medically verified carbon monoxide poisonings and one fatality. To better understand the factors contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out studies in a 12-foot diameter sphere to identify key factors that may enhance the levels of CO associated with the detonation of several commercial trenching explosives. The gaseous detonation products from emulsions, a watergel, and ANFO blasting agents as well as gelatin dynamite, TNT, and Pentolite boosters were measured in an argon atmosphere and compared with those for the same explosives detonated in air. Test variables included explosive formulation, wrapper, aluminum addition, oxygen balance, and density. Major contributing factors to CO production, under these laboratory test conditions, are presented. The main finding is the high CO production associated with the lack of afterburning in an oxygen poor atmosphere. Fumes measurements are compared with the manufacturer’s reported IME fume class and with the Federal Relative Toxicity Standard 30 CFR Part 15 in order to gain an understanding of the relative toxicity of some explosives used in trench blasting.

Jan 1, 2003

By Sebastián Seria, Jorge Álvarez, Diego Cáceres

The capacity to break the rock into adequate size fragments and in a cost-effective way is one of the main challenges in large open pit copper mines in Chile. That capacity is often compromised by the accuracy of geological estimations and the resources allocated by the mine site to update those models, making the blasting design highly dependent on that input and in consequence, blasting results. Given these opportunities, having an alternative method to input estimated key geological parameters allows blast designers to modify their designs and apply the appropriate energy to achieve the desired results. By using measurement-while-drilling data from boreholes and a few samples of actual, widespread, hardness measurements on site, we can deliver an updated cost-effective hardness estimation that is used as an input to improve the blasting design and its results on fragmentation. This estimation is delivered as a hardness interval – often in MPa units- related to the position of actual drilling measurements. In addition, having a sufficiently large drilling dataset allows us to predict hardness in new, undrilled areas near already measured boreholes, serving as a prior estimation available before pattern design. The use of these estimations, applied to several copper mines in Chile, allow us to more accurately determine explosive amounts and borehole drilling, which directly contributes to more productivity and efficiency in mine site operations. The results are often related to narrowing the gap for fragmentation results, even so, in some cases that will be related to direct savings in Drilling & Blasting process in a range 5-10% of the budget, due to powder factor changes.

Jan 26, 2026

By Mathias Jern, Ruilin Yang

A blast vibration model has been developed that simulates effects of almost all blast design parameters on the blast vibration peak particle velocity (PPV) from a production blast with multiple blastholes at a given point of interest in the rock. The velocity of detonation (VoD), initiation points, explosive types (density, VoD, energy), charge decoupling, and decking in each blasthole are simulated along with other blast design parameters. The information from signature hole blast vibration and the blast design are the input to the model. The model can be used to assess blast damage in proximity of blastholes as well as far field vibration PPV.

Jan 1, 2019

By Abraham Lindo

Taboguilla is a small island located 10 miles outside the Panama Canal Pacific Entrance. In 2002 a fuel distribution facility was installed in order to supply fuel to vessels passing thru the canal. The current capacity of the tank farm is equivalent to 1,100,000 barrels. The demand for marine diesel at this location still exceeds the current capacity, thus an expansion project is currently underway to increase the available space for diesel tanks. There is a total of 800,000 cubic meters to be excavated in order to create the new space. 400,000 cubic meters of that total is basalt rock which will need to be blasted

Jan 1, 2011

By L. O. Souza, J. F. Gewher, M. P. Scussiatto, C. S. Mendonca, R. A. McClure, B. T. Kuckartz, J. Kloeckner

Blasting is the most effective and economical tool available to fragment and move rock for most applications. If properly executed, it can improve down-stream operations such as loading, hauling and crushing. It is not possible, however, to have full control over the energy released by the explosives when a poorly designed blast pattern is used. A poorly designed blast can produce serious damage to equipment and create a potentially hazardous condition to people. Advanced mining technology has been developed to address these potential hazards and optimize the blast pattern. This profiling technology can assist with blast planning and provide quick, precise data about the condition of the rock structure to be blasted. The 3G BlastMetrix system presented here uses three-dimensional (3D) stereo photogrammetry to model the rock mass in a fast, practical and safe manner. Through the image overlapping method, a 3D model is created with thousands of points that provide a significant amount of data regarding geology, geometry and topography conditions. The blasting plan can then be made in a way to optimize the rock fragmentation and avoid areas that could create flyrock. This paper is a case study concerning usage of stereo photogrammic surveying and borehole survey systems in a blasting operation at the Brazilian Quarry, Incopel. One 3D image of a drilled bench was generated using photogrammetry survey technology and the borehole survey data collected using the rodded Boretrak borehole survey system. Utilizing the minimum burden profile reports, explosive loading could be done accurately, resulting in an optimized blast with good heave and fragmentation as well as increased safety.

Jan 1, 2013

By S. Nakamura, H. Taniguchi, K. Noguchi, H. Sugihara, T. Matsuzawa

It has been reported that expanded poIystyrene and ANFO prills ‘were mixed on a blasting site for controlled blasting (ISANOL). Although there seems to be few possibility of their segregation because mixing on a blasting site is done, there is a great possibility of segregation in packing, transportation and loading of the product due to the different densities of the two ingredients in Japan where mixing on a blasting site still remains inoperative. The fiee-flowing property of ANFO prills was lost with the passage of time because the Abel oil infiltrated into the expanded polystyrene and that gave the product high viscosity.

Jan 1, 2001

By Sam Oaks, David A. Smith

The new Corridor "G" Federal Highway Project in Logan County, West Virginia is the largest mass excavation highway project currently being built in the United States. Seven sections covering 14 miles of four lane highway and two connector roads will require over 30 million cubic yards of excavation. Construction is on a fast track schedule requiring the contractors to complete excavation and pavement placement in a little over 19 months. The two different general contractors have implemented several innovative Blasting and Excavation Programs to complete this project within the tight completion schedule. The paper expands on some of these unique programs that made the project a reality.

Jan 1, 1994

By P. Katsabanis

Numerical modelling was used to examine damage in wall control operations. Decoupled charges appear to create larger damage zones than fully coupled low density charges with similar charge distributions: Air was shown to be a very efficient coupling medium, while water coupling resulted in significant damage. However, Mach stems are formed when air is used as a decoupling medium, leading to compression of the charge ahead of the detonation wave. Air decked charges generate two damage zones, one close to the charge and another close to the air-deck/stemming interface, where pressure pulses are reflected. The extent of the latter depends on the length of the air-deck.

Jan 1, 2001

By Roy McKinstry

In March of 2001, Barrick Goldstrike became the first surface gold operation in North America to evaluate the advantages of electronic detonators. A detailed study was conducted to quantify the benefits of the use of electronic detonators to the downstream excavation, crushing and ore processing operations. The following methods were used to quantify blast performance: High speed film and video monitoring Firing time and rock response analysis of the high-speed films Digital fragmentation analysis of the post blast muckpile Vibration waveform analysis (including Fast Fourier Transforms and seed waveform modeling) Excavator performance quantification Crusher, SAG mill and ball mill performance evaluation Ore recovery analysis Cost/benefit analysis

Jan 1, 2002

By Andre Pinsonnault, Francois Lefebvre, Yves Newman

In 1989, Les Entreprises Kiewit Ltee signed a C$32 million contract with the Societe d'energie de la Baie James, on behalf of HydroQuebec, to excavate the intake and tailrace channels for a second powerhouse at the LO-2A James Bay hydroelectric project. The multistage contract included removing three marine rock plugs. The first plug was blasted in April 1990. It was a 43 yards wide, triangular shaped wedge that projected into 18 yards of water. Located at the mouth of the intake channel, it contained over 72,000 yd3 of rock, more than twice the 30,000 yd3 found in most rock plugs.

Jan 1, 1991

By Courtney Vallejo, Rafiqul Tarefder

This study examines the effects of small scale airblast experiments on cohesive soils and the resulting ground vibrations and crater geometries. Relationships for ground vibration attenuation with soil depth and distance from the blast source were developed. The study is part of a broader research topic of understanding the vulnerability of earthen embankment dams to blast loading. Many earthen embankment dams in the United States were constructed more than fifty years ago and were not designed to withstand high-stress loading such as blast loading. These structures may be susceptible to failure and it is important to describe the response of the earthen dam during a blast event.

Jan 1, 2013

By Daniel Roy, Chris J. Preston, Ron J. Elliott

This paper discusses the use of pressure transducers in water filled boreholes in conjunction with surface mounted geophones to gather field data for in-situ dynamic rock properties determinations. A high speed collector is used to capture the data in the field. The calculated P and S wave velocities and rock density measurements are used as input into the Blastcalc program where the values of Young`s Modulus and Poissons Ratio are calculated. The rock properties information is used along with geological structural data and explosives properties in a 3-D blast modelling program to calculate predicted fragmentation distribution and other blast performance criteria based on the proposed blast design.

Jan 1, 1996

By Aris Tambunan, Nella Lubis, Nurafrianti Saala, Komang Widhiayanto, Herry Saputra, Rudolf Sitorus

Maximizing mining recovery rates and minimizing ore loss are pivotal objectives for economic efficiency and operational effectiveness. This study explores methods to address these imperatives by enhancing ore production and recovery through improved blasting techniques and spillage control in the Martabe Gold Mine Project in North Sumatra Province, Indonesia. Between 2018 and 2021, the average mining recovery rate stood at 93%, resulting in a potential annual ore loss of 7% and a potential quarterly financial impact of close to $2 million. Maintaining and enhancing mining recovery became crucial, with a planned 30% increase in total material movement for 2022. The mining recovery target for 2022 was set at 96% based on best achievement historical data from 2021 to increase ore tonnage by 203 KTon per annum. To achieve the primary objective of increasing ore production by improving mining recovery, the study focused on predicting and controlling the movement of blasted ore to reduce spillage and enhancing the grade control model to reflect actual conditions post-blasting. Several alternative solutions were explored, primarily emphasizing drilling and blasting activities. Essential methods included capturing the actual blasting movement to adjust the ore block based on blasting design data and post-blasting muckpile topography. This approach minimizes ore loss by providing output as ore block adjustment based on post-blast movement data. In addition, the tie-up design was adjusted to control ore spillage outside the pit ridge. The implementation of these methods yielded significant improvements. Adjusting the ore block based on actual blasting movement contributed $1,545,764 in benefits. Controlling ore spillage outside the pit ridge achieved a 10% reduction in spillage, contributing $79,184 in benefits. These enhancements successfully met the 2022 mining recovery target of 96%, marking a 3% increase from 2021. Consequently, ore loss was reduced by 178 KTon throughout 2022, resulting in a financial impact of $7.3 million. The study underscores the significance of precise blasting techniques and effective spillage control in enhancing mining recovery rates.

Jan 21, 2025

By Kirlk Yeager

"Ammonium nitrate (AN) is commonly mixed with a wide variety of additives to produce specialty formulations. Two additives commonly utilized are sodium nitrate (SN) and sodium nitrite (SNi). Application of the nitrite is primarily limited to gassing of emulsions. The nitrate, however, is incorporated in a wide variety of formulations. The effect of both these materials on the thermal stability of AN was examined. Experiments initially utilized lab-scale testing methods (sub-milligram sample size), such as differential scanning calorimetry (DSC), with scale-up to cook-off analyses (16 g) eventually applied. Labscale testing indicated that the presence of SN and SNi (both at 5 wt%) produced no harmful effects on the thermal stability of AN. The cook-off results did not agree with those from the lab-scale analyses, with both SN and SNi creating tremendous thermal destabilization of AN. These effects were seen at additive levels as low as 0.1 wt%. When SNi was employed as the additive, cook-offs became violent enough to create explosions in the testing apparatus. Although SN did not create as spectacular a destabilization, it did lower cook-off temperatures to approximately the same level as SNi. The dangerous situation created by SN andSNi seemed to be limited to cook-offs conducted in sealed vessels. If the SN/AN or SNi/AN formulations were allowed to cook-off in vented vessels, the thermal destabilization of AN did not occur. These results seemed to indicate that even “trace” amounts of what might ordinarily be viewed as benign additives could create significant destabilization of AN-based explosives under proper circumstances. Conditions created by blocked pumps, or deep boreholes could well overlap those produced in sealed cook-off vessels. In addition to showing the hazards potentially created by “benign” additives, the study also stressed that experiments designed to evaluate thermal hazards must include duplication of field variables to the fullest extent possible. "

Jan 1, 1999

By Koichi Kurokawa, Takeo Ueda, Masahi Nakano, Yoji Tasaki

A lightning strike generates several 10kA and several billion volts, and earth currents generated by lightning is dangerous to some underground and all surface blasting operations. In order to evaluate the safety against lightning in conventional electric firing method and electromagnetic induction blasting system, a test is conducted by connecting a wire with an impulse generator. Frequency of impulse current used in the test is 17kHz and the waveform is a vibration type and the duration time is 250 ~usec. The results of the test show that induced current increases with the increasing of impulse current. In the case of MBS connection, when maximum primary current is 1700A, Maximum secondary current is 11.8A and the electric detonator is fired at this condition.

Jan 1, 1988

By Jesus Pascual, Jose Sanchidrian, Pablo Segarra

The surface vibration field in the area above an underground mine prior to its development has been investigated, in order to assess the vibration levels expected in existing buildings and in the planned mine facilities from future underground blasts. Shots of 50 and 100 kg of explosive placed in drillholes at depths of 100 to 150 m were fired, and the vibration events were recorded using an array of 40 seismographs in a 400 m square grid, covering a 2×2 km area. Contours of isovelocity were obtained for each shot, showing some directional transmission patterns. Propagation laws were obtained from the results of each shot and also from the bulk of data, both for the whole area and dividing it into four quadrants. The shift of dominant frequency with distance was also analyzed.

Jan 1, 2002

By Lex L. Udy

Properties of an explosive which itiuence its performance on rock breakage are analyzed in relation to the rock: hardness and a discussion on the interaction of an explosive with the rock during the blasting process is given. Theoretical concepts regarding ideal and non-ideal detonation are reviewed to explain how the physical and chemical factors of an explosive influence the rate of energy release and its consequence on blasting performance. While a lower velocity of detonation indicates a slowed chemical reaction it does not necessarily mean a loss in energy from the explosive. High density ammonium nitrate (HDAN) can be used effectively in the formulation of modern industrial explosives to slow the energy release rate with its attendant decrease in detonation velocity. Examples of blasting performance using custom formulated explosives with HDAN are presented.

Jan 1, 1995

By Erkan Bayrak, Serkan Erkara, Ozkan Duzgun, Ekin Gungor

This paper presents part of the outcomes of the drill and blast optimization project carried out at Kisladag Gold Mine in Turkey. Kisladag Gold Mine is the largest gold mine in Turkey with a low-grade, bulk-tonnage, open pit operation that uses heap leaching for gold recovery. After blasting, the ore is fed to a three-stage crushing circuit which prepares crushed ore approximately -10 mm (0.39 in) for heap leaching. Crusher downtime analysis showed that blocky material and insufficient feed are causing significant downtimes with the primary crusher. This was supported by the fragmentation data collected to date. It was decided to initiate a fragmentation project to understand the variation in the run-of-mine (ROM) size with a view to provide a consistent feed to the crushing circuit. The study includes the analyses of the ore strength and structure, image analysis of the fragmentation pictures acquired from blasts, blast auditing and quality assurance and quality control (QA/QC) analyses. During this project, over 200 fragmentation pictures were acquired from 47 blasts to optimize ore and waste blasts. Ore strength varies between 30 and 120 MPa and rock quality designation (RQD) ranges between 30 and 100. A site-specific fragmentation model was used to calibrate the fragmentation for blast domains formed. In addition, alternative cases were simulated to achieve blasts designs with consistent ROM fragmentation size distribution. Alternative blast designs that include stemming length and powder factor changes were suggested. Long stemming length, drill cuttings use, free faced blasts, small shot sizes and poor stemming length control were some of the key issues causing coarse fragmentation.

Jan 1, 2015

By Michael Wieland

The thrust of this report is to overcome some of the technical deficiency in the scientific methodology that correlates the work output during a charge explosion to the resulting toxic fumes. Thermodynamic work-principle models yield (undissipated) shock and heave results for shooting underwater and in rock stratum with related toxic fumes. Underwater circumstances yield reliable test data for the work process, though questionable or no fume results. Work-output measurements in rock shots remain difficult if not intractable, though some fume reports exist. Underground tests with thick-wall metal pipe bombs yield consistent toxic fumes trapped within the test chamber. The work output, rendered as fragment kinetic energy, can be inferred from the well-tested theory of R. W. Gurney, originally designed for military ordinance. Therefore a work-principle model for cylindrical pipe bombs was developed to predict fragmentation work output and reaction-zone fumes, permitting the double comparisons to reported and inferred results.

Jan 1, 2010

By Randy Martin, Jessie Bonner, Peter Boyd, Mark Leidig, Timothy Rath

We conducted the Vermont Damage Experiment in central Vermont during July 2008. Five single-hole explosions with yields ranging from 60.8 kg (134 lbs) to 122.5 kg (270 lbs) were detonated in homogeneous, low fracture density granite. The goal of the experiment was to quantify the different levels of rock damage around the source and then relate the seismic wave generation to the degree and distribution of damage and fragmentation. In addition, explosives with different velocities of detonation (VOD), including black powder (0.53 km/sec; 1737 ft/sec), heavy ANFO (4.8 km/sec; 15734 ft/sec), and COMP B (8.1 km/sec; 26574 ft/sec) were detonated to relate the VOD to seismic wave generation and extent of damage zones in the source region. Over 120 seismic stations were deployed to record the explosions at distances between 5 m and 30 km (15 ft to 19 miles).

Jan 1, 2010