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By César Ugaz Castañeda, Paulo Fernández Alvarado, Richard Sotomayor Oblitas, Rocke Enríquez

Mina El toro has been making substantial changes in its operation to improve its social impact and productivity. Because of the use of gasified emulsions and electronic initiation system, it was possible to mitigate vibrations and carry out massive blasting, increasing its production by 4.2% and minimizing complaints from communities.

Feb 1, 2020

By Harry Thompson

In using explosives to blast stumps from the ground in order to prepare it for farming, it is comparatively easy to place the charge under a stump having a semitaproot or a lateral system of rooting by boring or digging a hole in the earth to a point under the center of resistance and deep enough to give the desired effect.1

Jan 1, 2015

By Michael Twomey, Alastair Torrance, Alan Twomey

Low density explosives have been available in various forms for nearly 20 years. These initially consisted of various diluted forms of ANFO formulated to slow the rate of reaction. One such product that was developed was a blend of ammonium nitrate and rubber. This product uses a coarse fuel provided by granulated rubber to slow the reaction rate of the explosive rather than being a diluted form of ANFO. There has always been a technical difficulty in blending two dissimilar materials without subsequent segregation.

Jan 1, 2011

By Donna Kliche, Charles Kliche

It has been previously documented that various weather conditions such as wind direction and speed, cloud cover and, especially, temperature inversions can significantly affect the overpressure generated by a blast event (Siskind et al, 1980; Oriard, 1999; Siskind, 2000). The overpressure can be magnified downwind and reduced upwind; a change in the regular profile of temperature with elevation can magnify or focus the sound intensity at some distance from the blast event.

Jan 1, 2011

By Dr. Calvin J. Konya, Anthony Konya

Blast violence has always been a criteria that has been analyzed without a quantitative approach relying on opinions of those viewing the blast and oftentimes does not transfer between open-pit mines, quarries, and construction projects. Added to this confusion is that on many regulate projects, such as U.S. Army Corp of Engineers construction projects, the definition of "flyrock" or violence can vary, and contractors must be able to meet this requirement. This project analyzed hundreds of blasts from various construction projects to develop a new metric to determine blast violence - the Violence Factor.

Feb 1, 2020

By Dr. Calvin J. Konya, Anthony Konya

Blast violence has always been a criteria that has been analyzed without a quantitative approach relying on opinions of those viewing the blast and oftentimes does not transfer between open-pit mines, quarries, and construction projects. Added to this confusion is that on many regulate projects, such as U.S. Army Corp of Engineers construction projects, the definition of "flyrock" or violence can vary, and contractors must be able to meet this requirement. This project analyzed hundreds of blasts from various construction projects to develop a new metric to determine blast violence - the Violence Factor. If a blast is fired using 1.25" (32 mm) diameter product and a 10-foot (3 m) bench, vertical uplift of 60 feet (18.3 m) would be considered extreme and violent by any professional in the industry. However, a 100-foot-high (30.5 m) bench using 12" (305 mm) bulk product, having a vertical displacement of 60 feet(18.3 m)might be considered typical or non-worrisome. This is where violence factor is beneficial as itprovides a system of scaling the violence of a blast based on the bench height to give manager a keyperformance indicator (KPI) which is easy to monitor and can provide a large amount of information onsite-specific design variables for their performance on blasting and the end-results of the blast. The Violence Factor of a blast is an integer which is scaled to determine how high vertical uplift of a blast is compared to the bench height. This project analyzed numerous blasts to determine what blast design variables contribute to violence. This violence has also been shown to occur when a non-optimal breakage mechanism, cratering, occurs and the design criteria that lead to this cratering. Finally, this paper will present typical results of various levels of violence including backbreak, fragmentation, and muckpile configuration.

By C De La Cruz

The use of a thin-film piezoelectric stress gauge to determine the pressure profile in a detonating explosive has been demonstrated. These PVDF gauges have measured, in the borehole, the Chapman-Jouget pressure and the release adiabat of the detonation products for several explosives including ANFO and ANFO/emulsion mixtures. The technique can provide: (1) a direct measure of the blasting stimulus, (2) a sensitive QA tool for the blaster, and (3) a means to examine the magnitude and effects of preshock from adjacent bore holes. The PVDF pressure gauge is self powered, can measure pressure from a few bars to 400 kbars, has high time resolution (0.05 µsec), and is easy and economical to use.

Jan 1, 1997

By Ron Ketterling

We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes

Feb 1, 2020

By Raden Haris Handayana, Jihan Farhan Lubis, Milia Putri, Tengku Deli Hamonangan Hasibuan, Sani Salahudin

An environmental issue that must be controlled from coal overburden blasting near the structure is ground vibration. Damaging ground vibration is the effect exerted from residual energy from blasting that does not work to fracture the rocks. Sebuku Tanjung Coal is a coal mining that operates T3 Pit adjacent to the High Voltage Tower. This structure is included in the Class 5 building with a maximum Peak Particle Velocity (PPV) of 40 mm/s. The shortest distance from the blasting location to the structure is 105 m. The initiation system used is electronic detonators combinate with emulsion as an explosives type. In Indonesia, the government regulated vibration limitation on SNI 7571:2010. The blast outcomes targeted are PPV below 40 mm/s, fragmentation size <80 cm for Excavator Komatsu PC-2000, and digging time <12 seconds. In this paper, the blast design was engineered by conducting Signature Hole Analysis for optimizing delay timing configuration and Scale Distance regression analysis to determine optimum charge weight per delay at the blast site. PPV results from 30 blastings achieved 100% below 40 mm/s with the range of about 1.773-30.250 mm/s. The deviation between PPV prediction to PPV actual is less than ±18% which provides the blasting with electronic detonator resulting in good PPV prediction for controlling vibration. The average fragmentation size (D80) is 55.81 cm in the 1st layer and 54.81 cm in the 2nd layer. The average digging time is 10.30 seconds in the 1st layer and 10.12 seconds in the 2nd layer.

Feb 6, 2023

By Perry Sisk

In order to protect nearby structures during a blasting project, a peak particle velocity limit is often stipulated by a government agency or the owner of a particular structure. At the start of a blasting project, a preliminary estimate for the minimum scaled distance is often determined using a vibration prediction equation before any site-specific data have been obtained. Reasonably conservative assumptions are typically made for the unknown input variables in the vibration prediction equation until site-specific blasting data have been obtained and evaluated. Although this approach is prudent, it provides no assurance that the peak particle velocity values generated during the initial phase of the project will be below the specified limit.

Jan 1, 2013

By John Wall

The use of electronic detonators in civil tunnelling applications, to reduce vibration is small firings has been successfully utilised for a number of years. As part of the mining industry’s commitment to reducing blast damage during the development cycle in underground mining applications, a series of development blasts using eDevTM electronic detonators in typical mining applications was conducted in North Queensland, Australia.

Jan 1, 2012

By Ron Ketterling

Donna Summer wrote and recorded a song in 1983 with Michael Omartian called, “She Works Hard for the Money.” The song was inspired by her encounter with an exhausted rest room attendant, Onetta Johnson, who is mentioned in the song by name, and featured on the album’s back cover. ISEE President James Daley, in the May/June 2019 in The Journal of Explosives Engineering discussed the Six Pillars related to the ISEE. We will use the Internal Processes pillar to frame this discussion. The Internal Process Pillar includes five separate sub-committees – we will see how this concept applies to both ATF Explosives record-keeping compliance and business process compliance in general. We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes. This paper will show you how to make the hard work of inventory management and ATF record keeping work hard for you.

By Italo Onederra, Miguel Araos

"Most of the current explosives for mining blasting activities are based on ammonium nitrate (ANFO, emulsions and watergels). AN-based explosives’ detonating properties were discovered in the 50’s and since then they have proven to be reliable, safe and cost effective. However, there is no current alternative raw material to replace AN. As part of a program of research initially funded by the Australian Coal Association Research Program (ACARP), Mining3 and the University of Queensland engaged in the search for potential oxidizing agent alternatives that could replace AN in the manufacture of mining explosives. Candidates included those that are produced in large quantities and that can be cost competitive with ammonium nitrate. The initial work identified hydrogen peroxide (HP), calcium ammonium nitrate (CAN) and sodium nitrate (SN). Explosives mixtures were prepared and sensitized using void sensitization techniques. The detonation properties results showed that explosives based onmixtures of HP/CN and HP/SN as the oxidizer were able to detonate in a range of 2000 – 5000 m/s, indiameters 50 and 102 mm, and densities in the range of 0.50 – 1.40 g/ml. Although more studies need to be conducted to fully understand these explosives, if successful, these explosives would be able to offer an alternative to the AN-based explosives in the mining industry."

Jan 1, 2017

By Sayantan Chakraborty, Kaushik Dey, SaKaushik Dey tyabrata Behera

Drilling and blasting is a popular excavation technique in the drift of underground mine. Faster completion of drift reduces the gestation period and thus longer blast pulls are attempted with longer drill holes. This compels the blasters to initiate higher charge quantity with higher confinements and ultimately results into blast-induced cracks beyond the desired periphery line of excavation. Assessment of the extent of these crack networks is difficult and often neglected. Near-field ground vibration models are often used as damage predictors (Dey, 2007, Yang et.al 1993, Holmberg et. Al 1979) but not necessarily deals with the positions of the cracks. Qualitative measurement of actual damage extent often measured using some geophysical tools, namely, P-wave velocity (Tezuka, 1995), seismic imaging (Dey, 2011), bore hole pressure monitoring (Brent and Smith, 1996), electrical resistivity (Grady and Kipp, 1993), GPR (Adams et.al, 1993) etc. Ground Penetrating Radar (GPR) is a similar geo-physical tool, which uses Electro-magnetic (EM) pulse for characterizing the medium. Similar to other geo-physical tools, GPR also comprises of a transmitter and one/multiple receivers to generate the EM pulse and receive the same after reflection/refraction from the medium(s) respectively. After its development in 1970s, GPR gained increased popularity due to its application in many important fields, namely, identification of buried objects, geological characterization, identification of geological disturbances etc. Thus, it is felt that GPR technique can be used to detect the invisible cracks inside the rockmass from the rock surface (wall and roof) itself. Understanding the same, field experimentations are carried out in an underground manganese mine in Central India, which operates on the ‘cut and fill’ method of mining at a depth of around 300m from the surface. Wedge cut blasting is carried out in the horizontal drifts of the mine using suitable blast design. A 1.6 GHz antenna was used for the GPR scanning, in which GPR transmitter transmits signals predominantly of the said frequencies. The signals get reflected back from any type of interfaces between materials in the target area, with different dielectric properties and is received by the receiver part of the ‘trans-receiver’ antenna and memorized in the Data Acquisition Unit (DAU). The data acquired is processed using a software. Ground vibration monitoring of the blasts are also carried out to develop a vibration predictor. The numerical analysis of near-field vibration predictor model results into the estimated vibration levels at the point of identified cracks. Introduction

Jan 1, 2019

By Thomas E. Ricketts

Occidental Oil Shale, Inc. constructed two commercial-sized modified in situ (MIS) retorts, Retorts 7 and 8, at its Logan Wash Oil Shale Mine in February and April 1981, respectively. One of the primary objectives of this two-retort program was to examine large-scale blasting reproducibility for commercial-sized retorts. The blast design used 545 blastholes and 550,000 pounds of explosive in ANFO equivalent per retort. Each retort was blasted using millisecond delay blasting caps tied into a single round. The blasts resulted in rubble beds very close to one another and to predicted results obtained using newly developed limited void blasting technology. The heights of the remaining void rooms over the beds after blasting were within 0.3 feet of one another. This excellent reproducibility is brought into true perspective when compared to the scale of the rubble beds which were 230 feet high with volumes of over six million cubic feet each.

Jan 1, 1984

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 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 D J. McLane, J T. Rathbun, B T. Lusk

The dynamics of explosive detonations are understood, however recreating a real-world, full 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 paper is to better the understanding of how the waveform characteristics resulting from an explosive detonated within a shock-tunnel differ from those in an open-air arena test. The variables of comparison between an open-air arena test and those conducted within a shock tunnel are peak pressure, impulse, shock wave velocity, and cross sectional shape of the shock front. Understanding how these variables differ, tests utilizing a shock tunnel can be conducted with a higher degree of accuracy and repeatability.

Jan 1, 2013

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 Robert Hopler

INTRODUCTION NOT so very many years ago the farm was about the last place where one would expect to find up-to-date mechanical appliances. Steam, explosives, electricity—the factors which have made the world in general, and America in particular, what it is today— were indispensable for the railroad and the steamboat, the factory and the mine, but the farmer’s work was generally run on a comparatively small scale, and was mostly done by the muscles of men or draft animals. Today, however, the farmer as well as the manufacturer, the contractor and the miner, fully appreciate the value of labor-saving devices. Every up-to date farm, large or small, has modem machinery that tends to reduce the cost of production or to improve farm products.

Jan 1, 2011