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By Bethany Witter

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? The Virginia Tech Student Chapter of the International Society of Explosives Engineers handled this same issue with its recruitment efforts and event planning from 2017-2019. The first critical component of integrating Generation Z college students into the extractive industries is clear and frequent communication via email. Next, Generation Z often values the motivation behind work when choosing a career, so advertising technological advancements, benefits, and ways people can contribute to improving the industry also helps attract young generations. Similarly, advertising opportunities for people to work outside with their hands, travel, and secure stable careers can attract students. At Virginia Tech, the most effective way to attract and maintain the interest of students in extractive industries is to put the students in the field. Field trips to mines and factories experienced the most stable attendance and highest survey reviews of all other chapter events. Guest presentations from industry professionals were often well attended, but attendance tapered off as the academic year progressed and students grew busier. Periodic trips throughout the year maintained student engagement and often supplemented their curriculum. The student chapter was relatively successful in attracting students, but it struggled to maintain attendance levels in the latter portion of the academic year. In the future, the industry can increase its recruitment of Generation Z and Millennials into the workforce by working more closely with university programs to provide resources and opportunities for hands-on experiences for students.

By K. Ram Chandar, Vedala Rama Sastry

Fragmentation and muck pile profile together play an important role in optimizing the excavation costs for given geo-mining conditions. Initiation system is one of the vital parameters influencing the fragmentation and muck pile throw (profile). An attempt is made through this paper to study the characteristics of muck pile produced in addition to fragmentation. Two new parameters namely “throwburden ratio” and “muck pile ratio” are proposed for assessing fragmentation and movement of material. Field investigations were carried out in a limestone mine in southern India with shock tube and detonating cord initiation, using four initiation patterns, keeping other parameters like burden, spacing,delay timing etc. same.

Jan 1, 2008

By D. Scott Scovira, Thomas Gustavsson

The potential of hydrogen peroxide explosives was introduced to Thomas Gustavsson and Robert Håkland by Dr Miguel Araos through his development of hydrogen peroxide gel compositions (HPG). In 2020, Thomas and Robert developed a concept project with Boliden Minerals and received Swedish government funding to evaluate HPG technology in a mine environment. The project showed HPG reacted violently with mine mineralization and concluded that HPGs did not offer a commercial solution due to safety concerns. Thomas and Robert engaged with Stefan Nilsson to develop hydrogen peroxide emulsion (HPE) compositions and the process techniques to manufacture them. In 2021, laboratory work produced a promising low carbon intensity, nitrate free, ammonia free, emulsion formulation based on industrial grade hydrogen peroxide and a fuel-emulsifier phase. Design and construction of an HPE pilot plant and underground charging unit commenced. The manufacture of hydrogen peroxide emulsion shares several similarities with the production of nitrate-based emulsions in that the plant is a facility to blend a strong oxidizer solution with a liquid fuel phase into a finished emulsion. A key differentiator between HPE and nitrate-based emulsion is that the manufacture of HPE is a cold production technology in that neither the oxidizer phase (HP) nor the fuel-emulsifier phase requires high temperature heating to prepare raw materials. A successful proof-of-concept HPE evaluation ran from April 2022 to October 2022 at Boliden’s Kankberg underground mine in Sweden. This evaluation demonstrated HPE technology's safety, performance, production, handling, and indicative environmental benefits.

Jan 21, 2025

By Andrew Ritter, Victor I. Montenyohl, Stephen R. Winzer

Thirty-seven open pit production blasting operations have been monitored using high-speed cameras running between 500 and 7000 frames per second. Analysis of the resulting films reveals irregularities in timing including sequencing errors and crowding (holes firing less than 8 ms apart), confirming results of laboratory testing of ms delay blasting caps (Winzer, 1978). Where blasting parameters are otherwise constant and within recommended guidelines (stemming, spacing, burden, etc.), timing problems dominate the overall performance of the blasting operation. Model tests in layered Homalite 100, designed to simulate joint or bedding planes in rock, indicate the importance of the stress waves generated by the explosive in developing the crack network which is ultimately responsible for the fragmentation seen in the resulting muckpile. These mechanisms are strongly supported by high-speed film studies at Pinesburg, Maryland. Experiments in controlling relief in deep shots (where depth approaches the lateral extent of the bench blasted) using borehole geometry and hybrid initiation systems (electronic timer and pyrotechnic delays) were carried out. The results suggest that the 1 me/ft. of burden guideline developed by Bergmann et aI., 1974 is too short, and that much longer times are necessary to optimize fragmentation and muck digability. Longer times are found to reduce noise, vibration, and flyrock.

Jan 1, 1979

By Paul Worsey, Seokbin Lim

In many high explosive applications, the explosives are covered or clad by a metal. This metal cover may serve a variety of purposes including: 1) to protect and prevent the disturbing or misshaping of the explosive during its transportation, handling and use, 2) in many military applications the cover material itself is used to provide a required effect, for example, the shrapnel from grenades, the metallic liner of shaped charges, and the confinement of explosives so they perform optimally, and, 3) in civilian applications in the use of well perforating shaped charges and linear shaped charges used for the demolition of steel structures such as bridges. For these reasons the interactions between the explosives and their covering materials are of great importance in understanding the performance of these devices.

Jan 1, 2005

By Luiz Felipe Mendonça de Amorim, Adimir Fernando Rezende, Gustavo Sampaio Lopes, Claudio Cesar Gajardo Arraño, Eltton de Sousa Veras, Manuel Villalobos Calderon

Many technical challenges were encountered while conducting near-field construction blasting between the critical intersection of Interstate 10 and multiple active railroad tracks in El Paso, Texas, for the Loop 375 Border West Expressway Project. Blasting was utilized for the removal of an andesite bedrock ridge in preparation for the construction of a new elevated super structure to be suspended over the existing railroad tracks. There was concern that the excessive vibrations and/or permanent rock deformation produced from the blasting within near proximity (20 feet, or 6.09 meters) of the railroad tracks would induce excessive stress and foul the tracks by shifting the alignment. This could result in a major loss of scheduling control between the two major railroad companies that operate in this area. There was also concern that the blasting may cause rock fragments to land on and interfere with critical interstate transportation. Blasts

Jan 1, 2019

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 B T. Lusk, Jhon J. Silva

"The original signature hole technique to predict vibration levels from blasting, is based on theassumption that each hole in a production blast, generates an identical vibration waveformarriving to the point of interest. When the same waveform is used to represent the vibrationproduced by each hole, the complete waveform for the whole blast is the convolution betweenthe waveform and the impulse sequence that represents the initiation timing of the blast. In thisresearch, several field tests were developed to establish the validity of the invariability of thewaveform hole-to-hole in a mining production blast. The results of the tests showed that thereare variations in amplitude and frequency content for the hole-to-hole waveforms. Thevariations can be explained due to the character of the parameters involved in a production blastbetween them: different vibration path for each hole, differences in the geometry of each hole,differences in the explosive charge for each hole (chemical and quantity), etc. This paperdescribes a methodology based on the main characteristics in both; time and frequency domainof any recorded signature waveform and uses Fourier series to approach one equation to generatedifferent random waveforms for each hole that can be used in the prediction of the completevibration record of the blast. The methodology is the base for signature hole analysis using aMonte Carlo scheme."

Jan 1, 2012

By Robert Hopler

Complying with our request in the February issue of the AGRICULTURAL BLASTER for items that would be of interest to other blasters, Mr. Thomas H. Benton of Tennessee sends us an article in which his methods of securing contracts are explained:

Jan 1, 2013

By John Brennan

The Avalauncher has been an integral tool for avalanche mitigation work for close to 50 years. With their ability to place a kilogram of high explosives up to two thousand meters away, they routinely serve as a short range alternative to military artillery. The Avalauncher’s roots can be traced to a pneumatic baseball pitching machine used by Major League Baseball teams in the United States in the late 1950s. Throughout the decades, many modifications have been made to both the launcher and its projectiles. Current technology has allowed the Avalauncher to attain greater accuracies and operational range. In this paper I plan to cover not only the history of the Avalauncher but also explore its potential future.

Jan 1, 2009

By Doug Hoy

The scope of the Cliff Avenue Reconstruction Project in Sioux Falls, South Dakota was to widen a two lane highway to five lanes, along with removing and reconstructing both above and below ground utilities located along the project limits. The objective of this paper is to present the blasting techniques used in the rock excavation phase of the Cliff Avenue Reconstruction Project.

Jan 1, 1992

By Bruce B. Redpath

This paper reviews empirical and analytical information about window breakage due to airblast. As is the case with damage to structures caused by ground vibrations, a fixed break/no break threshold is inapplicable and window damage must be expressed in terms of a statistical probability. The information is summarized in a graph showing the probability of windows being broken by a given level of overpressure.

Jan 1, 1976

By Timothy Smith, Matthew Ryan, Dr. Anthony Konya

Hybrid specifications are a relatively new style of specifications specifically for the drilling and blasting industry that has seen widespread use over the last decade with the U.S. Army Corp of Engineers. This paper analyzed how this methodology was applied to develop this specification for the Soo Lock Deepening Project.

Feb 1, 2020

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 Steven V. Crum, David E. Siskind

In response to its own concerns and those of the public, industry and regulatory agencies, the Bureau of Mines is studying the impacts of low-frequency blast vibrations on structures. Previous research has identified potential problems associated with low-frequency ground vibrations and also found that their existence was not particularly rare, given large surface mine blasts and certain geologic conditions. Only a limited amount of data existed in the blast vibration literature on structure response to ground-vibration frequencies below 6 Hz.

Jan 1, 1993

By David Harrison

The Charleroi Locks and Dam (Figure 1) was completed in 1932 and is located on the Monongahela River, approximately 22 miles (35 km) south of Pittsburgh, in Charleroi, Pennsylvania. It is comprised of a 420 foot (128 m) gated dam, and a 720 foot (219 m) by 56 foot (17 m) land side lock which provides for a 16.6 foot (5 m) vertical lift.

Jan 1, 2015

By D Linn Coursen

Detonation propagates in the subject blasting agent at about 2.7 km/sec when it is heavily primed but explosion propagates in it at only about 0.43 km/sec when it is lightly primed. When propagating at 0.43 km/sec, it produces a borehole pressure that is slightly less than 1 kb, but no yellow fumes or other sign of incomplete reaction. It is a pumped AN/emulsion blend to which additional water is added by circumferential injection at the inlet of the hose through which it is pumped.

Jan 1, 1994

By Catherine T. Aimone-Martin, Brent Meins

Blast vibration monitoring for buried pipelines is typically conducted at the ground surface with a shallowly buried geophone. In many jurisdictions across the U.S., blast-related vibration limits set for pipelines are dictated by surface measurements and do not consider the significant reduction of PPV amplitudes acting on the pipe at depth. This study involved a vertical array of geophones deployed in drilled holes at two blasting sites of the Loop 202 South Mountain Freeway construction project in Phoenix, Arizona. City of Phoenix pipeline engineers were concerned that blasting would damage an aged 48-inch (122 cm) prestressed concrete cylinder pipe (PCCP) that serviced water for South Phoenix

Jan 1, 2019

By Michael Wieland

Delay blasting in underground coal generates shock waves and rifting forces that damage charges remaining in the blast pattern. Damaged charges detonate poorly, raise fume toxicity and reduce coal breakage. Such circumstances could be prevented by using explosives resistant to cross-hole interaction damage. The design of rugged explosives is fraught with contradictory requirements, but tradeoffs related to hard-particle size characteristics prove useful. Hard particles, related voids or trapped bubbles represent reaction nucleation centers which strongly influence the performance of coal mine explosives.

Jan 1, 1992

By M. Ganster

Austria’s biggest supplier of oil and gas, transports gas through the West Austria Gasline for domestic consumption. In addition, the OMV also works as gas carrier and ensures the transit into neighbouring countries.

Jan 1, 2010