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Computational techniques in determining particle size distributions after blasting is getting wide acceptance. A well known approach to extract this kind of information from digital images is edge detection. The number of edge points on a given image increase proportional to the increase of the particles on the image. By selecting a conveniently smooth threshold, counting the signed edge pixels may be a suitable metric further used to quantify the number of particles in the image. Here we propose an image processing algorithm together with Adaptive Neuro Fuzzy Inference System (ANFIS) to efficiently count the rock particles with various sizes on a given surface. To determine a suitable approximation for a mapping between the number of edge pixels and the number of particles, ANFIS is a suitable tool. As a trainable classifier ANFIS proved itself as being better efficient approach than other well known multilayer perceptron classifiers. ANFIS is trained by using convenient training data pairs previously experienced from empirically counted sample images. When given a new image containing the particle information of selected surface, the hybrid neuro fuzzy image processing approach provides satisfying performance on counting the correct number of particles up to the given scale of sizes. In this paper an experimantal study for assessment of particle size using ANFIS is presented.

Jan 1, 2004

By Josephine Bones, Robb Larson, Daniel Miler

Avalanches are commonly mitigated through the use of explosives at ski resorts and above transportation corridors. Surprisingly, very little research has been conducted on snowpack response to explosive inputs, and efforts to model this response have been limited. The purpose of this ongoing research project is to ascertain an understanding of the dynamic snowpack response in relation to explosive size and height above the snowpack, coupled with snow conditions, to enhance avalanche control. A system of sensors and computer-controlled data acquisition components has been created to record the movement of snow resulting from the charge detonation. The system records acceleration vertically and radially within the snowpack at two distances from the point of detonation as well as blast air pressure at one location during explosive events. The data at two locations allows inferences to be made about the transmittance and attenuation of shock waves through the snowpack radially as well as vertically. The data shows that raising charges above the surface results in increased snowpack dynamic response when compared to surface detonations. Applying power function regression to accelerations for individual charge elevations, it was determined that both radial and vertical rates of attenuation were not dependant on charge elevation. Additionally, raising the charge also resulted in increased dynamic response at depth within the snowpack

Jan 1, 2012

By J S. Kuszmaul

"A computational model of rock blasting is being developed to examine the blasting problems associated with in situ oil shale processing. This model, however, will also be useful as a design tool for the traditional problems in rock blasting. The model includes fundamental treatment of both shock-wave propagation and the accumulation of brittle fracture in the rock. As a result, the model accurately predicts the degree and extent of fracturing as functions of design parameters. The model has proven useful for making parametric studies and for evaluation of alternate blast designs. This paper demonstrates the use of the numerical model to simulate the fracturing induced by the detonation of a vertical explosive column near a bench. The fracturing induced by three differentexplosives indicate that (in the chosen geometry) the most efficient breakage is done by a column of ammonium nitrate and fuel oil mixture (ANFO) used with a toe charge of aluminized ANFO. There was too much unfractured rock left when ANFO was used alone; aluminized ANFO used for the entire explosive column caused excessive fracturing. A final case involves ANFO used alone to fracture a different rock type. This case points out that in a different rock type, the ANFO will not leave excessive unfractured rock."

Jan 1, 1987

By Michael J. Burrell

Sands Hill Coal, located in Wellston, Ohio produces coal for steam generation and crushed limestone for the aggregate market in southeastern Ohio. This paper concerns the blasting and production of the limestone which lies between the #5 and #4 coal seams. The limestone bed averages 8 to 10 feet in thickness and is overlain with 17 to 20 feet of shale from the floor of the #5 seam.

Jan 1, 1990

By G Alan Foster

Because of the marked human response to blast effects and inherent defects present in many modern structures the real possibility of being named as a defendant in a law suit faces most blasters. Until recently even frivolous law suits involved a great deal of expense since legal costs were inevitably incurred whilst waiting for your day in court, which typically occurred some 2-4 years after the alleged damage took place.

Jan 1, 1989

By E. McCullough, D. Preece, M. Ortel

The mining and oil industries employ techniques such as geologic mapping, core drilling and electromagnetic field techniques to explore for new deposits. New discoveries of major near-surface ore bodies are becoming progressively rare and traditional exploration methods are unable to resolve ore bodies deeper than about 500 m (1640.4 ft). Consequently high-resolution seismic reflection techniques show great potential for exploration to much greater depths down to almost 3 km (1.9 mi).

Jan 1, 2013

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 Wiliam Reisz

As we approach the peak season for thunderstorm activity it’s important to keep in mind that lightning still poses a serious threat to drilling and blasting operations. Lightning remains the number one cause of accidental detonation of explosives.

Jan 1, 2008

By Laurent Airaud

For around ten years, electronic detonators are available for those who want to use advanced methods and to apply theories promoted by engineers and professors to reduce blast concerns or improve fragmentation and dilution. Furthermore, decision makers can verify the use of electronic detonators to drive down mining costs. Engineers and more specifically blasters are the actual users and have to be convinced of the easiness of electronic detonators. This paper deals with electronic detonators and the notion of easiness. Common feelings about the notion of easiness are discussed. Then, examples of new technologies like, automobile, photography or Information Technology are discussed to observe how they progressed throughout time with new features and sales volume. For the specific explosive initiation industry, each step of the life of an electronic detonator is dealt with concerning the easiness and a table is used to quantify this notion.

Jan 1, 2004

By Angelina Anani, Seffit Aderuyi, Sylvester Avane, Joseph Wilson-Sey, Amatus Niminye

The Edikan mine in Ayamfuri, Ghana, faces economic challenges and community resistance due to its proximity to residential areas, particularly concerning blasting operations. Controlled blasting trials using air deck applications were conducted to address community concerns by minimizing environmental impacts and explosive costs. This method involves utilizing an air gap within blast holes to prolong the action of shock waves on the rock mass, enhancing crack formation and reducing rock movement. The trial project at the Edikan open pit gold mine aimed to evaluate the effectiveness of air deck blasting in reducing ground vibrations and overpressures, and to assess its impact on blast performance and economics in the prevailing geological conditions of meta-sediment and hard granite rocks. Results indicated lower Peak Particle Velocity (PPV) and Peak Sound Pressure Levels (PSPL) values in the air-decked blasts. Additionally, more uniform rock fragmentation and enhanced blast economics were achieved. Explosive costs were reduced by 20–24%, saving $0.97 to $2.24 per hole depending on the rock type. Overall blasting costs per volume decreased to $0.54 in granite and $0.48 in meta-sediment compared to conventional methods.

Jan 21, 2025

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 K. M. Kim, J. B. Kemeny

A case study was conducted with 5 shots with varying pre-blast block sizes and explosive energies. From this case study a site-specific predictive fragmentation model was developed. There are two main innovations in this study. One is using an image analysis program (Split-Desktop 3.0) on the bench face to obtain the pre-blast block size (F80) quickly and consistently. Another innovation is to utilize the Schmidt Hammer Hardness (SHH) to estimate intact rock strength.

Jan 1, 2011

By Rodney Pinksen, Remi Proulx

The IOC Mining and Operations Departments expressed an interest in reducing the amount of oversize material (>1.0 m x 1.0 m x 1.0 m; 39 inches x 39 inches x 39 inches) being produced and its subsequent downstream effects including in-pit sorting and reduction, damage to mobile equipment, and significant delays in the loading pockets and the primary crushers. To achieve this goal an oversize reduction project was undertaken by the mine and to date has significantly improved upon baseline measures.

Jan 1, 2011

By Brent Blanchard

The use of explosives to safely fell structures can be traced back over 300 years. Since then, dozens of chemists, inventors, blasters and demolition experts worldwide have played prominent roles in the evolution of what has become the modern-day explosive demolition industry. In America, one of the earliest applications of explosive demolition occurred in response to the great fires of San Francisco, where homes and businesses were blasted with gunpowder in a desperate attempt to create firewalls. Later in the 19th century, inventions such as nitroglycerine, dynamite and blasting caps made structural blasting a safe, efficient alternative to conventional demolition methods. The 20th century brought the first experiments in shaped charge technology, and this, combined with developments in portable seismology and non-electric delay systems, allowed an ever-expanding variety of structures to be explosively felled by demolition experts throughout the country. The 1950s and .60s brought a new wave of commercial structural-blasting entrepreneurs (several of whom are still active today), and their efforts towards improving adjacent-structure protection and public relations beget the felling of large commercial buildings in dense urban environments. By the late 1980s, publicity-driven motives were gaining greater influence in the decision to .implode. various structures, and the transformation of blasting operations into promotional spectator events played a role in several injuries and fatalities. Since that time, however, a renewed sense of responsibility practiced by most blasting firms and project officials has resulted in the safe, successful completion of hundreds of recent endeavors. In sum, what appears today as an efficient, economical - and visually spectacular - way to demolish structures has its roots in developments of the past several centuries

Jan 1, 2002

By James Ludwiczak

This paper consists of the conduct of a forensic criminal investigation of the components, construction, use, and functioning of two suicide bombs. As the title states, the task was to form professional opinions as to whether the bombs would work, would cause property damage, and would injure or kill. The bombs were created and installed by a defendant in a Federal death penalty case where the defendant’s daughter was killed in a shootout with the West Virginia State Police. The two black powder bombs were placed under the front seats of the defendant’s automobile and were designed to function by the use of a toggle switch connected to the automobile’s cigarette lighter. The forensic work first consisted of an inspection of the remains of the wiring system and bombs at the Bureau of Alcohol, Tobacco, and Firearms Laboratory, in Ammendale, MD. This was necessary to determine and detail the wire diameter and lengths, the lengths and size of the wire used, the type of toggle switch used, the type of containers, the type of rocket motors used to initiate the black powder, the manufacturer and amount of black powder used in each bomb, and the type, wraps, and amount of duct tape used for the construction of each bomb. Using this data, tests were conducted by duplicating the wiring system and the two bombs to insure that the system functioned properly. Each bomb was duplicated and initiated to observe the violence produced when initiated in the open air. Duplicate bombs were placed under the seats of a similar type of automobile and initiated. The purposes of the tests were to duplicate the bombs, to observe the violence of the initiation, and to observe the damages to the automobile produced by the initiation.

Jan 1, 2007

By D. Scott Scovira, Rick Webber

The Iron Ore Company of Canada [IOC] is a global leader in Arctic mining applications, and the blasting crew have something to be very proud of. On Wednesday 21 Dec 2005 at 3:28 PM the largest single bench blast in the company history was detonated. The successful firing of this 5.0 million tonne [5.5 million ton] blast surpassed the previous company record of 3.8 million tonnes [4.18 million ton].

Jan 1, 2008

By Jeffrey Meissner, Mike Waldron, Charles Dowding

Most studies of crack response have focused on opening and closing of a crack in the plane of the wall in which the crack occurs. Crack movement also occurs perpendicular or normal to the plane of the wall. This paper will examine and compare the in-plane and out-of-plane (normal) response of cracks in two different residences near limestone quarries. In two locations, sensors that measure in-plane and normal displacement were installed side-by-side on the same crack, allowing direct comparison of the two modes of response. In a third location, a perpendicular pair of displacement sensors was installed in a corner of a room to observe the bidirectional response of the structure at a corner. Both long-term and dynamic data were recorded with the same sensors; temperature, humidity, and air over pressures were also recorded to compare blast and weather effects. Measurements show that ratios of out of plane to in plane response to dynamic events can vary. However, the ratios of out of plane (normal) response to vibratory events to that of climatological change is still as small as the ratio for in plane crack responses.

Jan 1, 2010

By Peter Cameron, Tom BoBo

Comminution, being the energy intensive part of a mining operation receives much scrutiny by cost controllers, CEO’s, investors and others as the mining industry goes “back to basics” to reverse the decline in productivity which occurred during the mining super cycle.

Jan 1, 2019

By Vincent Thorne

On January 2, 1992, the R. Zoppo Company of Stoughton, Massachusetts started drilling and blasting operations on U.S. Army Corps of Engineers Project Number: DACW33-91-B-0072 to widen and deepen the Portsmouth Harbor and Piscataqua River Navigation Channel.

Jan 1, 1993

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