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By Piotr Mertuszka

Many years of research on more effective and safer explosives have led to the development of emulsion explosives. They are the second most commonly used group of explosives worldwide, primarily because they are good alternatives to ANFO or dynamites. Their key advantage in underground applications is the lower content of toxic fumes in the detonation products. Emulsions are also characterized by high detonation velocity, high water resistance, low critical diameter, and mechanical loading capacity. Several factors affect the behavior of emulsion explosives. These factors are related to both manufacturing and applied mining methods. The most important factors include the charge diameter, type of sensitizer, density, hydrostatic pressure, ambient and charge temperatures, as well as the time elapsed between the charging of the explosive into the blast hole and its detonation. The selection of the type of explosive is based on the analysis of a number of parameters, including the density, critical diameter, volume of the post-blast fumes, detonation pressure, velocity of detonation, and sensitivity to external energy sources. In most cases, the conditions under which explosives are used differ significantly from those defined in standards. Such conditions cover, among others, the temperature of the rock mass and surroundings, humidity, rock strength parameters and the diameter of the blast holes. Consequently, the parameters of the explosives provided by the manufacturers may not correlate with those specified in-situ. Thus, within the framework of this study, the effects of the selected technological parameters on the detonation velocity of bulk emulsion explosives are presented. The analysis focused primarily on the factors directly influenced by the mine blasting services. The detonation velocity measured using the continuous wire resistance technique was used as the evaluation criterion. For this purpose, several underground in-situ tests were conducted, including the impact of the blast hole diameter, density, initiation method, sleeping time, and temperature on the detonation velocity. The results of in-situ tests have shown that the detonation velocity of bulk emulsion explosives depends strongly on the above factors, which may directly affect the effectiveness of blasting operations.

Jan 26, 2026

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 Rolf Schillinger

Transport of Small Quantities of Explosives Material on Public Roads The transport of dangerous goods on public roads is extensively regulated by EU and national law. The transport of explosive material is not only done by forwarders but also by small companies and private persons with the goal of their own use. The following article tries to explain what is allowed and what is not.

Jan 1, 2010

By Tapan Goswami, Lloyd Hain, Geoff Brent

For many years Ramp 24 at Ensham mine in Queensland, Australia has suffered substantial coal loss and damage due to the fragile nature of the coal and problematic geological conditions, which have proved very challenging. In the past various blasting techniques were applied in attempts to improve coal recovery. One approach was to use a shallow throw (cast) blast followed by a separate post-strip blast underneath. Another method was the introduction of the practice known as “baby decking” with the addition of a large buffer of material in front of the coal. However, despite increasing mining costs, none of these techniques adequately reduced coal edge loss and damage.

Jan 1, 2008

By Joseph Indeck, Seokbin Lim, Andrew Thompson

In the design of explosively driven penetration devices, understanding the impact conditions between the explosively propelled penetrator and the target is one of the most important steps in optimizing the performance of the device. These impact conditions are especially prevalent when a shaped charge jet impacts concrete, which is not an ideal target material. The specific impact conditions, including but not limited to the impact angle and jet properties, create a great deal of variability that affects the performance and penetration of the shaped charge. The large amount of impurities and voids in concrete, along with its heterogeneous nature and the general strength characteristics, make concrete a non-ideal material for shaped charge jet penetration. These material characteristics lead to a highly non-linear deformation behavior of the concrete target during a hyper-velocity impact.

Jan 1, 2011

By M. Araos

Non-ideal explosives can be characterised by different methods like velocity of detonation measurement, double pipe tests, underwater tests, aquarium tests, etc., to name a few. Both aquarium and velocity of detonation tests were selected to characterise a non-ideal explosive that is based on hydrogen peroxide, fuel, and void sensitisation. The detonation process in an aquarium of this sensitised explosive was captured at 80,000 frames per second using a high-speed camera. The explosive product was detonated using 51mm (2inches) diameter acrylic pipe charges. The product was detonated at different densities in an aquarium (cube box containing water). An aquarium provides a homogenous confinement for the detonation of explosives and more importantly, allows observing the shock wave as it changes the refraction index of water. The analysis of the video footage allowed the calculation of the velocity of detonation, pressure, gas rate release, and how the shock wave's shape in water changes with densities. It is suggested that the calculation of the rate of gas release could be related to the bubble data obtained from underwater tests.

Jan 1, 2024

By John Floyd, Larry Wardrip

A series of tests were conducted to evaluate the performance of a high density, high velocity cartridged explosive. The tests included two production blasts in a limestone quarry and two production blasts in a granite quarry. To quantify blast and product performance, each blast was monitored with the following equipment: l Two (16mm (Lo Cam) high speed cameras (500 images per second) l Velocity of detonation recorder (I million samples per second) l Four face motion accelerometers (1 million samples per second) l Digital seismograph The fragmentation distribution produced by each blast was quantified with digital image analysis The benefits of the use of high velocity, high density toe loading was quantified in terms of: l Vibration reduction l Fragmentation improvement l Excavator performance In addition to the field tests, a comprehensive evaluation was performed to determine the cost/benefit relationship of the use of the toe load. This paper will include the findings of the study along with guidelines for use in other quarry operations.

Jan 1, 2002

By Dennis Wilzbacher, John Wiegand

In an effort to reduce the cost of bulk explosives, Vigo Coal Company found that the addition of coal mined at their Friendsville Mine, not only reduced explosive costs, but also appeared to actually enhance blasting performance. The Friendsville Coal lies at the base of the Mattoon geologic formation within the Mcleansboro Group of the Missourian Series of the Pennsylvanian Geologic System in Southern Illinois. Vigo Coal Company commissioned VIBRONICS, INC., an independent blasting consulting company to quantify actual blasting performance. Insitu sonic velocity testing of overburden was conducted to determine the P-wave velocity of the sandstone present at Vigo’s Cypress Creek Mine, where the initial testing was conducted. Numerous VOD (velocity of detonation) recordings were obtained for varying blends of ANFO/Coal (now named Carbo*Prill). Cast blast percentages were determined for both Carbo*Prill and non coal blended bulk explosive blasts. The VOD of the coal blended product was intentionally reduced so as to more closely match the P-wave velocity of the sandstone overburden. Explosive blends containing as much as 40-50 percent coal were tested. Explosive blends containing greater than 30 percent coal, have been used in Cypress Creek Mine overburden production blasts. The coal blends appear to produce better fragmentation and yield excellent cast blast performance. Safer mining conditions were also observed. Flyrock potential was reduced. The blasts produced less back break, producing a safer highwall. Stripping dozer and shovel production rose during the testing period and equipment repair costs were lowered due to an increase in overburden fragmentation. Blasting vibrations were reduced, in part due to the lowered detonation velocity of the ANFO/Coal mixture. The Friendsville Coal Seam appears to contain inherent chemical and physical properties that enhance blasting performance. The use of Carbo*Prill has been approved by MSHA, BATF, the State of Illinois, and the State of Indiana. This paper will provide details concerning testing procedures, blast performance analysis, recommendations and conclusions for using this alternative blasting mixture.

Jan 1, 2007

By Robert McClure, Carlton Lehman

Rendering safe explosives in an urban environment presents a unique challenge due to the safety concerns and disruption to the general public. Potential damage to the surrounding homes, businesses, utilities and transportation infrastructure are some of the major concerns when planning the render-safe operation. Engineering controls to mitigate blast effects, such as damaging air over pressure levels, material ejection and ground borne vibration, need to be implemented as part of the operation. Monitoring of seismic and air overpressure during these operations are needed to protect against potential claims when controlled or unplanned detonations occur. Two recent render-safe operations conducted in and around urban environments dealt with deteriorated, sensitive dynamite and damaged blasting caps. Utilizing innovative neutralization chemicals and processes to render-safe the deteriorated dynamite, while protecting the general public, proved to be the safest, most environmentally responsible and cost-effective way to approach the problem. In both cases, the explosives, old dynamite and detonators were found in abandoned, unlocked magazines. The dynamite was in a significantly deteriorated state, which was evident due to the nitroglycerine found leaking in,around and under the dynamite cartridges. Iron wire permissible electric blasting caps were also found in a corroded condition with exposed explosives and un-shunted lead wires. With occupied buildings within 180 feet (54.86 meters) of the magazines, any procedure (e.g. transporting, countercharging, burning) that could potentially cause a detonation was not an option. In the event of an unplanned detonation during neutralization operations, several blast mitigation methods were employed to safeguard the site. This operation and a similar one with over 1,000 pounds of crushed and buried leaky dynamite were unique since all the explosives were rendered-safe and neutralized on site. The use of advanced neutralization products and filtering processes allowed for a safer, more environmentally responsible way to resolve the problem. The magazines and all residual solids and fluids were tested and confirmed by independent labs to have no explosives residues. The effluents were treated on site, tested and met safe levels, so they were disposed of at a local municipal wastewater facility.

By Christopher Jon Preston, Troy Williams, Daniel Roy

There has been significant progress made with narrow vein gold mines in which a second option for crushing has begun to attract attention. To ensure the profitability of a mine that has based its economics on the absence of a crusher station, more than just best blasting practices are required. Using a blasting operation itself as a primary crusher would undoubtedly save enormous capital costs as well as eliminate some of the costs of crushing ore with the result that considerable savings might be realized. The challenge would be to define the conditions necessary to make this type of operation feasible by providing consistent blasting methods that result in a significant paradigm shift with respect to both blasting and current underground crushing methods. A break model has been developed and applied as a technique in designing blasting patterns based on a unit charge blasting geometry and stress reflection from free faces. There are four components to this model and these are 1) unit charge, 2) thermodynamic/energy, 3) stress reflection, and 4) radial break. Some important changes in timing between holes and rows based on rock properties and the percentage of burden moved were also used. On-site testing at a narrow vein gold mine in Quebec Canada, provided measured parameters for the model. No underground crusher was planned - relying only on the fragmentation profile generated by ring blasting. The specification for muck was that the fragmentation profile needed to be 100% < 400 mm (16 in) with no overbreak - with dilution less

Jan 1, 2019

By Lon Santis, Bill Evans, John Tatom

Debris data from the Department of Defense Explosives Safety Board’s Project ESKIMORE full-scale explosives event test program are compared to quantity-distance (Q/D) standards and quantitative risk analysis (QRA) methods. The ESKIMORE test program involved quantities of explosives ranging from 1,000 to 60,000 pounds detonated in typically sized structures made of metal and concrete. Debris from these events was extensively surveyed and catalogued. The debris patterns from these events show varying degrees of directionality normal to the walls of the structures. These density patterns are overlaid an existing explosives storage site that is comparable to the test conditions. Analysis of the debris patterns in relation to Q/D standards shows that exposures located beyond the Q/D arc but along the normal to walls of potential explosion sites (PES) may have much higher debris density than exposures at the same distance on the corners of the same PES. Analysis of the debris patterns shows that predicted patterns using the QRA tool IMESAFR v2.0 closely match actual patterns. Additionally, IMESAFR based QRA methods are able to quantify the different risk levels of being exposed along the wall’s normal as compared to being exposed on the structure’s corner. Methods and decision making criteria to mitigate risk based on the directionality of PES debris are presented. Copyright ©

Jan 1, 2015

By Stewart A. Silling, D. Lynn Gordon, C. Mick Lownds, Dale S. Preece, Ali Bhuiyan, Patrick R. Bowden

Blast heave modeling and prediction utilizing the new discrete element model, GEM, that treats rock as elements with alternating arcs and line. Explosive loading of GEM elements is accomplished by utilizing the Noble-Abel equation of state to track the gas pressure from detonation through expansion to atmospheric pressure.

Feb 1, 2020

By Luis Huaroc, Jorge Cardenas, José Salvador

One of the current challenges in mining is managing increasingly competent rock conditions within the mine-to-plant value chain, particularly when working with marginal ore grades. This study presents a case from a Peruvian open-pit operation where the mine plan projected a significant increase in rock hardness, as measured by the Axb index (parameters derived from the JK drop weight test). In response, the Drill and Blast Technical Team made efforts to increase the powder factor by reducing drill spacing and increasing the explosive charge, employing high-energy explosives (3,090 kJ/kg). However, this adjustment presented a challenge in achieving the fragmentation required to meet the target throughput of 97,500 tons/day, resulting in a shortfall of approximately 8.7% under the base case scenario. To overcome this technical challenge, the use of locally engineered ultra high-energy explosives was proposed, offering adjustable energy levels ranging from 3,210 to 3,570 kJ/kg. This solution enhanced ore blending strategies, calibrated to specific Axb ranges. The results also suggest that microfractures generated by the energetic blasting designs contributed significantly to downstream improvements. These outcomes demonstrate the value of a fully integrated mine-to-plant strategy, aligning blasting parameters with downstream processing performance to maximize operational efficiency. This solution led to a 10% increase in process plant efficiency, a 16% reduction in specific energy consumption during primary crushing, and a 13% reduction in the SAG mill. Additionally, shovel productivity rose by 18%, and the dig rate improved by up to 35%. Keywords: fragmentation, blending, high-energy explosive, power factor, microfractures, specific energy consumption and Axb model.

Jan 26, 2026

By Robert McClure, Carlton Lehman

Rendering safe explosives in an urban environment presents a unique challenge due to the safety concerns and disruption to the general public. Potential damage to the surrounding homes, businesses, utilities and transportation infrastructure are some of the major concerns when planning the render-safe operation. Engineering controls to mitigate blast effects, such as damaging air over pressure levels, material ejection and ground borne vibration, need to be implemented as part of the operation. Monitoring of seismic and air overpressure during these operations are needed to protect against potential claims when controlled or unplanned detonations occur.

Feb 1, 2020

By Gregory Hempen, Thomas Keevin, Russell Wilcox, William Wild

The Department of Defense Strategic Environmental Research & Development Program (SERDP) awarded funding for evaluation of procedures to mitigate peak pressures and energy flux density in the water column from ordnance being detonated on the ocean floor. The research purpose was to conduct scaled testing to resolve whether a theoretically-viable covering technology was operationally effective in reducing blast effects and the impacts of shrapnel. An additional objective was testing effectiveness of this method for hard-bottom units (rock or coral) and (unconsolidated) sediment substrate.

Jan 1, 2011

By Gabriel Gonzalez, Paulo Couceiro, Luis Manriquez, Alejandro Gutierrez, Juan Navarro

A high-stakes blasting campaign was successfully executed at a major open pit copper mine in northern Chile. This operation posed a significant technical challenge due to its immediate proximity to the tailings dam - a critical infrastructure whose structural integrity depends on strict control of blast-induced seismic vibrations. The geological complexity of the area, characterized by upper andesite interbedded with caliche (carbonate), further complicated the operation. This lithological composition, known for its high tenacity and cohesion, posed additional challenges for achieving effective fragmentation, necessitating a highly customized blast design and loading strategy. The campaign included four production blasts and one secondary blast, all executed under the constraint of not exceeding the Peak Ground Acceleration (PGA) threshold of 0.64g, as defined by the Maximum Credible Earthquake (MCE) scenario. To ensure compliance, geophones were strategically installed at three monitoring points (P1, P2, and P3) on the dam to capture real-time acceleration data. The use of specialized blast patterns, precise stemming control, and electronically sequenced detonations ensured that all recorded accelerations remained well below the critical threshold. A total of 496,163 tonnes of material were safely blasted, with 8,452 meters drilled and powder factors ranging from 419 to 594 g/ton. Therefore, this case study exemplifies operational excellence in controlled blasting, demonstrating the feasibility of safe mining near geotechnically sensitive zones through predictive modeling, rigorous QA/QC, and post-blast analysis.

Jan 26, 2026

By Roberto Folchi, Hans Wallin, Mara Battocchio

An understanding of explosives science and technology, and the competence to harness it is central to maintaining Explosives capability, national security, and in sustaining a competitive industry. A consequence of eroding this competence is the increased likelihood of explosives accidents. These are often catastrophic as demonstrated by accidents in Nigeria, Russia, Toulouse and Enschede. In addition to the serious loss of life there was the very significant damage to houses, domestic and industrial infrastructure and to the environment at a cost of many millions of Euros.

Jan 1, 2013

By Gregory B. Poole

Data collected with 16K sampling at a variety of blasting sites (construction, quarry, trench, mine) and monitoring locations was analyzed to effectively show the 16 different 1K readings all based on the microsecond that the unit went into monitoring.

Feb 1, 2020

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 Khiva Haidar Shauma Tassno, Zulham Ahmad, Farhan Harist Maharesi, Abdullah Badawi Batubara

Blasting operations can use a bulk emulsion explosive (EE) with a formulation based on used oil as a replacement for refined fuel oil. The most commonly employed used oil for making EE is a mineral based used engine oil that passes an impurity content standard. It is known that not all types of used oil are easily incorporated into EE formulations. Impurities in used oil can disturb EE stability resulting in crystallization and phase separation and consequently led to poor detonation quality. In 2024, a poor blast result occurred at an Indonesian mine due to utilization of used oil that was not within specification. A research project conducted from February to April 2025 found that used transmission oil differs from used engine oil in hydrocarbon composition. Transmission oil contains more additives that affect EE stability due to polarity differences and the disruption of colloidal state stability. Lab tests including stress testing and crystal growth observation aided the development of a stable EE formulation based on used oil and used transmission oil. In mid-April 2025, blast evaluations were conducted using the EE that was formulated using used engine oil and used transmission oil. Measurements of velocity of detonation, fragmentation, and digging time, demonstrated high quality EE was produced. Application of used oil in EE revolutionized the capability of mining operations to improve blast sustainability and cleanliness. Through comprehensive research, robust testing, and effective supply chain management, it is possible to replace some portion of refined fuel oil with used oil without compromising blasting performance. The inclusion of used transmission oil broadens the overall used oil specification and increases the volume of recycled used oil available for blasting. The increased volume of used oil available can reduce the amount of waste generated by mining projects while maintaining operational efficiency.

Jan 26, 2026