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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 Shazad Hosein, William J. Birch, Robert Farnfield, David Jameson, Catherine E. Johnson

The current and consented quarry workings at a slate quarry in North Wales {UK} intersect old long abandoned underground slate mine workings. The old underground slate mine contains the remains of World War II buildings used to house artworks to protect them from war damage. Over the past 20 years, there have been a number of roof falls in the old underground slate mine, which have damaged the buildings and make general access unsafe. From observation of the timing of these falls, they occurred in the mid 2000’s. The purpose of the exercise was to determine the possible relationship between blast vibrations experienced on the surface and those experienced on the roof of the abandoned mine caverns. Thus preventing the need to regularly monitor in the old mine workings. In order to achieve this, a rigorous geotechnical assessment of the stability of the caverns was undertaken by a fully qualified Geotechnical Engineer. Once it had been determined that it was safe to do so, 3 “MEMs based” blasting seismographs were attached to the roof, in accordance with the instruction of the geotechnical engineer. In addition, 8 “MEMs based” blasting seismographs were deployed at various locations on the surface. The trial blast comprised of 51 blastholes, with charges varying between 46kg [101lbs] and 124kg [273lbs] of bulk emulsion explosive. The blastholes were in 4 rows of holes. The blast was connected using shock tube 25ms, 33ms and 65ms delay period relay detonators. The minimum distances from the blast to the surface and underground monitoring points were 78.1m [256 ft] and 114 m [374 ft] respectively. The results from the three underground monitoring locations in terms of resultant peak particle velocity was 4.42 mm/s [0.174in/s], 3.47 mm/s [0.137in/s], and 4.69 mm/s [0.185in/s]. In line with previous research, it was determined that the underground results [when compared on a “like for like” basis in terms of scaled distance] were lower in amplitude than the surface results. In this case by a factor between 0.47 and 0.87, averaging 0.68.

Jan 21, 2025

By Callie Covert

This paper describes the application and results of a more efficient method of breaking boulders using dynamite and water. This method is being used for the disposal of boulders that result from pinnacle and cap rock remaining after blasting on highways and job sites. This method is a faster and less expensive use of dynamite to reduce oversized boulders than the conventional rock hammer. The problem with excessive fly rock has been substantially reduced when using this technique over traditional methods.

Jan 1, 2001

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 Lynn Long

We have seen many new developments in the explosive and blasting accessory category, but one of the most useful items is the blast control plug. Blast control plugs are cone shaped units that are placed in the stemming just above the explosive load. They are placed about 8 to 12 inches up into the stemming material.

Jan 1, 1996

By Benoît Pinier, Jason Furtney, Gustavo Sampaio Lopes, Jorge Valencia, Johan Hawinkel

This paper describes a numerical modeling study on the effect of airdecking on vibrations, fragmentation, and movement in mining-related rock blasting. Practice has shown that air gaps reduce blast vibrations and damage while maintaining the required fragmentation and movement, yielding similar blast outcomes with less explosive mass per hole. Given that the premise of “replacing explosives with air” for better blast results is counterintuitive, this paper aims to shed light on the physical mechanisms and processes occurring in a blast with airdecks. It is hypothesized that airdecks are effective and beneficial because they load the rock at pressures lower than what is required to crush the rock. In the airdeck, the explosive gasses directly fracture rock and avoid energy loss due to crushing. In essence, the airgap allows similar outcomes in fragmentation and throw with less total explosive product, as the lower pressure gasses in the airdeck are still effective at breaking and moving the rock. This is distinct from only having less explosive and more stemming, as the stemming reduces the pressure more than an airdeck at the same position. This study uses the blastFoam software (for modeling of single and multiphase flows) to accurately calculate the pressure history throughout a blasthole and air gap. The pressure and gas loading are coupled to numerical models of vibration, fragmentation, and blast movement. Using this modeling technique, a suite of blast scenarios for typical configurations in a range of commodities is assessed with and without airdecks. Rock blasting practitioners have a responsibility to protect communities, infrastructure, and heritage — demystifying airdecks through a better understanding of the physics provides another tool in the blasting engineering toolkit to serve this goal.

Jan 21, 2025

By Raj K. Rajamani, Solomon A. Tucker, Michael K. McCarter

"In a study aimed at exploring possible improvements in operating performance at an Open Pit Copper (OPC) mine in the western U.S., the impact of blast energy changes on crushing performance was evaluated. OPC feeds its 3-stage crushing plant in 12-hour-day shifts with skarn ore from three domains: Pit_B (B), Pit_S Low-Grade (SLG) and Pit_S High-Grade (SHG), in the blending ratio 1:1:1 (B/SLG/SHG). Thecrushed product is fed to a 2-stage ball mill circuit. "

Jan 1, 2017

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 S B. Richardson, D Mead, N T. Moxon

The use of air-decks to reduce explosive costs has become very topical in recent years. The majority of the research in this area has been arried out between the Soviet Union where reductions in explosive consumption of between 10-30% have been claimed with apparent benefits being gained in both fragmentation and movement. Work carried out by the University of Maryland using thick plexiglass blocks has supported these findings and indicated that air-decks in measetbe duration of action of the shock wave on the surrounding material by a factor of 2 to 5 (see Figure 1). Although the fracture network resulting from this mechanism is not as intense as that produced adjacent to the explosive charge it does appear to act over a larger volume of material. Although the mechanism attributed to air-decking has been studied in some detail the effect of this mechanism on the size distribution of material produced during a blast does not appear tot have attracted much attention.

Jan 1, 1991

By Kyle Apple

The following is a case study of how LuckStone Corporation improved their blast monitoring and documentation program. A number of resources already at their disposal have been utilized to improve the body of data collected from each blast. The tools being used include GPS, aerial photos, and a user-friendly push button format excel spreadsheet. The data collected include product by product records of materials used, distances to all concerned neighbors, seismograph data, etc: The spreadsheet has been designed to perform an ongoing analysis of blasting trends. The program has been carried out at a corporate level and is in use by blasters at each location. This paper addresses the advantages and drawbacks of this program. It also addresses the ways in which the various tools were integrated, Discussed as well is the need for simplicity when bringing “new” technology to the field and the steps taken in familiarizing the end user to changes.

Jan 1, 2001

By John Manka

Emulsion explosives consist of an aqueous oxidizer phase, a fuel phase, and an emulsifier. The ability to use lower-cost sources for any of these raw materials presents an obvious economic advantage to emulsion manufacturers. This paper focuses on using low cost waste drain oils as the fuel phase in emulsion explosive applications. Laboratory studies showed that emulsions made from waste drain oils and agricultural ammonium nitrate prills were usable for emulsion explosives though their shear stability was weak. Customer field results proved that waste crankcase drain oil could replace half of the virgin diesel fuel in emulsion explosives to make an effective emulsion explosive product with a very low cost.

Jan 1, 2003

By John W. Brown

"Adequate dust control in and around rock drills is a problem that must be solvedfor the health and safety of workers running the drill as well as those working around thedrilling operation This paper will discuss the designs available from most drill manufacturers todayand the effort ‘nvolved in keeping them effective on a productive basis."

Jan 1, 1999

By Charles E. Joachim

Railroad and blast induced vibrations were measured in the vicinity of the proposed Big Bend Cutoff. Peak horizontal and vertical particle velocity relations were developed using least squares regression analysis. The dominant frequencies of these data are in the range of 30 to 50 hz. Therefore, allowable charge weight per 30 msec delay curves were generated for buildings (2 in./sec) and unlined tunnels (8 in./sec). A blasting contour map is presented for this site.

Jan 1, 1984

By John Brulia

"Definition of On-Site Security: All mandatory and non-mandatory, deterrent and loss control measures undertaken by an authorized explosives business tokeep its stocks of explosive materials and precursors from: • (1) THEFT • (2) LOSS"

Jan 1, 2006

By Minoru Kawamora, Koichi Kurokawa, Kenji Hashimoto

We developed concentrated remote control blasting system to blasting simultaneously at a large number of sites in a mine of large scale. This system is consisted of three parts, the first part is a control station with high voltage power source units, the second part is a relay terminal with relaying and branching units, and the third part is a blasting machine with charging and discharging units. The control station is connected with the blasting machine by mean of control bus wire. The blasting machine adopts MBS(electromagnetic induction blasting system) for the reason of safety and good handling.

Jan 1, 1990

By Matheson and Miller

Does anyone have any definitive information on vibration limits for damage to well casings near blasting? Also, are people using self-imposed limits when approaching cased wells? I can only tell you what I have personally done with success. Often in new construction in hard rock, the well is drilled before the foundation is excavated and before the ditch for the water line is excavated. These both require drilling and blasting. Under these circumstances when blasting for the ditch for the waterline we will drill right up to within 10 inches (not feet) of the well casing. We drill line holes the width of the ditch, then about a foot from this, another row of trim holes then as we move away from the casing holes for 1 1/4 inch stick powder for about three rows then as we get further still, we can load with ANFO. I do not have vibration data for this but my experience has been that as long as you are not displacing the material into the casing that no damage is done. These typically are steel casings for residential water service.

Jan 1, 2010

By Geff Gordon, Dale Nies

Small diameter borehole blasting can be very efficient and cost effective. As residential development continues to expand, many areas are now requiring blasting for site preparation and upgrading old utility systems or constructing new ones.

Jan 1, 1990

By Matias Suarez, Diego Zenteno

This paper is aimed to display the new advancements of blasting engineering done in different mining sites throughout the country, associated to electronic sequencing, energy of the explosive and its impact on the fragmented rock. This document explains how to define and implement selective sequencing in the blasting in order to promote the propagation of cracks, therefore impacting positively the productivity through the use of the LaGrange diagram. The LaGrange diagram is a very convenient and illustrative method to present the dynamic behavior associated with wave and crack propagation (Rossmanith. H, 2002).

Feb 1, 2020

By Xu Tianrui, Jin Xiang, Pen Dianhua

Based on the results of research or investigation, this paper describes the causes of and countermeasures for unexpected accidents, such as premature, postponed or spontaneous explosions in blasting practices in China.

Jan 1, 1996

By Ed Jr Smith, Calvin J. Konya

The purpose of this paper is to describe the case history of a blasting project conducted jointly by Precision Blasting Services and Cherokee Explosives. It is the intent of the authors to show how blasting could be done in controlled fashion near very expensive computer controlled machinery. The job was done in minimal time with no complaints or allegations of damage in spite of the fact that blasting was conducted within five feet of the equipment and with the 32 acre plant fully operational, with machine operators working within 10 feet of the blasting site.

Jan 1, 1986