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By S C. Brashear, D A. Anderson, A P. Ritter, S R. Winzer, R Broughton

Results of quarry blasts can be quantified to show the effects of controlled variables. Two studies have been carried out: one to document the effect of delay on fragmentation and the other to show the effects of higher relief patterns and more accurate initiators. By using such techniques as highspeed photography and timing studies of mucking and crushing operations, subtle differences in blasting efficiency can be measured and quarry blasting can be optimized. Given the range of available and developing blasting technologies, quarry operators should resort to quantitative analyses of their blasting practices to get maximum productivity.

Jan 1, 1985

By Thomas M. Keevin, Gregory L. Hempen

A study was conducted to measure underwater pressures associated with confined borehole shooting used to remove rock for The Kill Van Kull Deepening Project, U.S. Army Corps of Engineers, New York District. A major natural-resource-agency concern was the potential for fish mortality during explosive rock removal. Currently, fish mortality models are based on testing programs that exposed captured organisms to open-water blasts. Natural resource agencies, without in-house explosive engineering expertise, generally are not familiar with the physical properties of blasting underwater. Confined shots are most often used for demolition and rock removal underwater. Pressure amplitudes from confined blasts are significantly reduced as compared to open-water blasts that, are commonly used for fish testing The duties of natural resource agencies are made even more difficult by the lack of published data on pressures associated with confined blasting. As a result, explosive weights for confined shots mistakenly have been used to run mortality models that were developed using open-water blast pressure data. This study was conducted to collect pressure measurements during rock removal for the KVK deepening project and compare those data with computed peak pressures for open-water explosions.

Jan 1, 2005

By Mike Wheat, Catherine Aimone-Martin, Brandon Pease

The Kneeling Nun rock pinnacle is a prominent landmark, 90 ft in height and 35 ft in width, that resides on a bluff overlooking the Santa Rita pit at the Chino Mines Co. operations near Silver City, New Mexico. The company plans to expand the current pit limits, resulting in a change in direction and distance of hard rock mine blasting operations in relation to the pinnacle. Concerns about the stability of the pinnacle adjacent to mining activity has prompted company personnel to enhance the seismic monitoring program both on the pinnacle and along the current open pit highwall that forms the base support below the pinnacle foundation. This paper presents the vibration response characteristics of the pinnacle, in terms of amplitude and natural frequencies of motions and damping characteristics, for measurements recorded at the top and base of the pinnacle. The influence that blasthole initiation timing and sequence of hole detonations have on vibration response is discussed. A simple analysis is made to estimate factors of safety against cracking of the landmark as well as blast-induced slope instabilities within the foundation rock.

Jan 1, 2000

By K. Dufresne

Blasting in geothermally high temperature ground and/or extremely reactive ground is an increasing common challenge for surface and underground mines. Many current PETN based non-electric and electronic detonators have manufacturer published in-hole temperature limits ranging from 55°C to 65°C (131°F to 150°F). When confronting blasthole temperatures above the manufacturer published limits, operations may request site-specific guidance and qualification for use. The advised safe loading window for in-hole PETN based detonators is often too short to be practicable for production blasting. To overcome limitations of PETN based initiation systems, surface mines with high temperature ground and/or reactive ground are known to load blastholes with a qualified high temperature bulk emulsion that are top primed with a cartridge of temperature qualified detonator sensitive emulsion plus an RDX detonating cord downline. As there is no in-hole delay detonator in this system, blasthole timing is accomplished with surface delays. Although this system is safe, top priming and surface delaying does influence floor quality and top size fragmentation, and safe loading windows times reduce blast block size and increase blasting frequency. A mining company with a site characterized by geothermally high temperature ground plus highly reactive ground employed a blasting system like the one described above. The site desires to improve blasting performance by moving to an in-hole delay initiation system that can withstand the site ground conditions. At the request of the mining house, DynaEnergetics (hereafter “the company”) developed an electronic initiation system for application in geothermally high temperature ground and/or extremely reactive ground conditions. The DynaEnergetics IGNEO high temperature electronic initiation system is rated for in-hole use in ground up to 150°C (302°F) for 48 hours. The detonator consists of a high strength detonator with an HMX base charge and thermally resistant downline. To make up a primer, the detonator is inserted into a booster charge assembly that is fitted with a small HMX shape charge. This high energy primer is designed to be compatible and reliable for firing bulk emulsions, including those with high percentages of urea inhibition to combat reactive ground. Up to 1000 detonators may be programmed in 1ms increments up to 1500ms. The system is controlled by a digital firing panel that can be used with either a wired or wireless trigger. The system enables high temperature and/or reactive ground sites to utilize in-hole delay initiation and realize the associated performance benefits

Jan 1, 2024

By David Leidel, Beth Shimer, James Stuart

Periodically, the Institute of Makers of Explosives Safety Library Publications are reviewed, edited and updated to reflect recent technical developments, new commercial explosive products and new regulatory requirements. The rapid proliferation of electronic devices, particularly portable communication systems, inventory management devices, navigational aids, etc., required the revision of the IME Safety Library Publication 20, “Safety Guide for the Prevention of Radio Frequency Radiation Hazards in the Use of Commercial Electric Detonators”. The new edition of SLP-20 has been updated to correct alterations to U.S. frequency allocations and maximum transmitted power permitted and a discussion of communications and tracking systems required in underground mining by the Miner Act. Also, an entire section was added dedicated to safe distances from RF sources to the special type of resistorized electric detonators used in the upstream oil and gas industry on wellsites and an enlarged section describing the particular types of RF sources that the blaster may encounter, perhaps in construction blasting operations.

Jan 1, 2012

By Benjamin Cebrian

Metallurgical testing at Cobre Las Cruces prior to production at the mill was done with overburden gossan. Some of that test gossan was a very fine material, wet by the water conditions at the bottom of the pit. When processed and stored wet at the fines material 3000 tonne (3307 tons) silo, this material cemented in a very unusual manner.

Jan 1, 2010

By Grant Small, Deon Pieterse

Reactive ground conditions at an open pit manganese mine in the Northern Cape of South Africa resulted in an unexpected detonation.

Feb 1, 2020

By Javier Castaneda, Luis Zozaya, Noel Huarachi, María Rocha

The objective of the project was to implement and calibrate drill and blast models supported by Geotechnical and Geological models as well as the mine and operation characteristics. The models would then be migrated to HxGN Blast to ensure a productive process that is simplified, digitized and optimized.

Feb 1, 2020

By Jonathan Heiner

Rio Tinto Bingham Canyon Mine started its South Wall Push Back (SPB) in 2011. This push back will mine through the only road to the pit bottom (the 10%). The pit bottom is the main ore sector for the mine and supplies about 80 to 90% of the ore. In late 2017 the mine set off a blast in SPB that created a small wedge failure on the high wall between SPB and the 10%. This wedge failure released a rock approximately 20 minutes after that blast that rolled down the wall landing on the 10% near and then contacting a light vehicle

Jan 1, 2019

By J. Aravena, S. Gajardo, M. Ayala, P. Salinas

Both, Teck Carmen de Andacollo (Teck CDA) and Orica, work hard in the implementation of new technologies available in the explosives industry and drilling and blasting techniques, with the objective of sustainable development of their operations, regeneration, and protection of the environment, also considering the welfare and relationship with the surrounding communities. The open-pit Carmen de Andacollo mine is located adjacent to the town of Andacollo. Therefore, both companies together have developed the implementation of different techniques and technologies to mitigate the impacts of mining operations in the community, considering an important part of this challenge to minimize the impact of their perception of blasting by reducing the level of vibrations and sound pressure (airblast), in addition to the control of dust and smoke, strengthening sustainable production in harmony with communities. The technologies and techniques that have been implemented are the installation of airblast and vibration monitoring stations stands out, whose database has records since 2011. Using the vibration database, different models were developed to predict the vibration level of blasting in its design phase, achieving a difference of 4.1% between the estimated and measured values in the last year. Two techniques stand out to minimize the ejection of material, "Hydraulic Dome" and "Dual layer blasting", the first consists of water irrigation on the surface to be blasted and the second is an unconventional blasting technique, which was awarded in 2015 for its results in the environment. Also pre-splitting engineering has been modified in a positive evolution, where through different configurations, the airblast has been reduced by 15% compared with records from 2011 to 2022. Finally, due to the impact of operational restrictions, such as days available to blast, number of holes, and powder factors, the wireless initiation technology was implemented, which allowed reducing the limitations in the loading, generating an improvement in terms of blasted materials over conventional systems. Understanding the restrictions and challenges in terms of impact on communities, the correct implementation of all these techniques is important, and in conjunction with collaborative work, it has been shown and validated that producing in a sustainable and sustainable manner is possible.

Jan 1, 2024

By Scott Stephenson

Making a tunnel through solid rock can sometimes be a dangerous task. Many things must be considered in order to complete such a task safely, and efficiently. Prior to starting things must be known such as, the type of rock, the purpose for the tunnel, the destination point, then angle of decent (or ascent). Once these things are known, the method to proceed must be considered. Factors such as cost, feasibility, and time to completion must be taken into account.

Jan 1, 2009

By Scott Scovira

All flyrock incidents have the potential to result in injuries or fatalities that can result in loss of company reputation, license to operate with clients, and bear the exposure to high cost liability. From 2007 to 2009, one NA Quarry and Construction Business experienced a series of flyrock incidents. In the Spring of 2009, this business declared that the frequency and severity of Flyrock Incidents had reached an unacceptable level. A Flyrock Elimination Program was launched.

Jan 1, 2012

By C. Heiss, A. Hofmann

Due to an explosion in an Austrian steel works during the basic oxygen process, the Chair of Mining Engineering and Mineral Economics at the Montanuniversitaet Leoben was assigned with the set-up of a test arrangement to study the effects of large-scale particle emissions on the plant´s installations and the testing of various structures and structure-combinations to be applied as explosive-proof enclosure.

Jan 1, 2012

By Jose A. Sanchidrián, Ricardo Castedo, Pablo Segarra, Juan Navarro

A study conducted at a mine site that used traditional field surveying and physical hole spot markings bench marked their combined drill and blast performance. The analysis of the operational expenditure (OPEX) improvement determined there were many measurable cost improvements. A primary factor that most operations have to deal with is over drilling of holes. This alone impacts the cost due to nonproductive labor allocations, excessive explosive costs, increased drill tool costs, increased drilling costs and has an impact on the downstream operation cost such as digging the shot material. Other related investigations also show a downstream impact of poor fragmentation on digging payload tonnes, cycle times, haulage payload tonnes, time to load a truck and the number of passes to load the tuck. The intent of this presentation is to draw attention to aspects of mining we understand but may be missing the big picture effects, such as the ability to reduce the operational expenditures consistently to impact the bottom line. The target audience is across the board from owner operators, drill and blast contractors to blasting contractors. Everyone can benefit from these improvements.

Jan 1, 2019

By Karl Dufresne

Blasting in geothermally high temperature ground and/or extremely reactive ground is an increasing common challenge for surface and underground mines. Many current PETN based non-electric and electronic detonators have manufacturer published in-hole temperature limits ranging from 55°C to 65°C (131°F to 150°F) and prescribed in-hole residence times on the order of days. When confronting blasthole temperatures above the manufacturer published limits, operations may request site-specific guidance and qualification for use. The advised safe loading window for in-hole PETN based detonators is often too short to be practicable for production blasting. To overcome limitations of PETN based initiation systems, surface mines with high temperature ground and/or reactive ground are known to load blastholes with a qualified high temperature bulk emulsion that are top primed with a cartridge of temperature qualified detonator sensitive emulsion plus an RDX detonating cord downline. As there is no in-hole delay detonator in this system, blasthole timing is accomplished with surface delays. Although this system is safe, top priming and surface delaying does influence floor quality and top size fragmentation, and safe loading windows times reduce blast block size and increase blasting frequency. The DynaEnergetics IGNEO high temperature electronic initiation system is rated for in-hole use in ground up to 150°C (302°F) for 48 hours. The detonator consists of a high strength detonator with an HMX base charge and thermally resistant downline. To make up a primer, the detonator is inserted into a booster charge assembly that is fitted with a small HMX shape charge. This high energy primer is designed to be compatible and reliable for firing bulk emulsions, including those with high percentages of urea inhibition to combat reactive ground. Up to 1000 detonators may be programmed in 1ms increments up to 1500ms. The system is controlled by a digital firing panel that can be used with either a wired or wireless trigger. The system enables high temperature and/or reactive ground sites to utilize in-hole delay initiation and realize the associated performance benefits. An underground mine in Western USA has several areas in their development heading with very high temperature, in view of this, they decided to use the IGNEO detonators in order to evaluate the effectiveness and performance of the system.

Jan 21, 2025

By Feng Shuyu Yang Nianhua

According to the results of high speed photography tests, particle velocity measurement tests and the digital calculation with TP2 software, the shape of shock wave, the declined laws of the shock wave propagation speed and the peak particle velocity are described and analyzed in detail. New viewpoints about the theories of blasting fragmentation based on analysis of the progressive pictures of the fracture region are given. The formula for calculating the depth of fracture regions is established on the basis of the new viewpoints.

Jan 1, 1997

By Paul Worsey, Larry Kenchel, David Randall, Mark Schmidt

The University of Missouri-Rolla (UMR) has historically maintained a manual, paper inventory of explosives stored and used at the university. Although this system was accurate for inventory control and reporting criteria, it was labor intense and delays in record keeping were predominant. A directive from the university’s administration mandated the development of a precise real time system “on-line” to maintain and control the explosives inventory in line with the universities new chemical tracking policies.

Jan 1, 2001

This is the story of a blast - not a large blast by todays standards as it only involved a total of approximately 50 cubic yards of rock. Nor did this blast involve any new or revolutionary blasting technique or require involved analysis or the applications of rock mechanics theories. Instead, it was a blast that involved the tried-and-true principles of good blasting: precise alignment of blastholes; selection of explosives and detonators designed for the conditions encountered; extreme care in loading and hooking up and the use of several ingenious devices and techniques to achieve the proper loading and firing of the blast

Jan 1, 1976

By Dirk van Zyl

Rock fabric information is often available from drill hole information and bench face mapping. An approach is presented to predict fragment size distribution of blasted material from this information as well as that obtained after the blast. The following information available from a mineral exploration drilling program was used in the prediction of fragment size distribution: largest piece, percent particles larger than 1 inch and RQD. Photographs of bench faces were used to estimate the fragment size distribution. Fracture spacings were evaluated along a series of parallel lines on the photograph. Photographic techniques were also used to obtain the grain size distribution of blasted material. m is paper describes the methodologies applied in some detail.

Jan 1, 1986

By William McFerren, Pragasen Moodley

In contrast to global trends, African, especially South African, surface mining operations have shown a significant rate of adoption of Electronic Detonators (ED’s) over the last few years. Proven benefits of converting to ED’s from pyrotechnic initiation systems have aided this market conversion. These benefits are experienced throughout the mining operation. Benchmarking exercises, prior to the introduction of ED’s, form part of the conversion process and allow for quantifying improvements. Extensive work has been done on quantifying the benefits of converting to ED’s and have shown that results can be reproducible. Improvements have been experienced in many applications and include environmental impact control, improved mining efficiencies, increased cast benefit and improved size distribution. These step changes in blasting results, in conjunction with the adoption of ED technology have aided the rapid conversion of the African surface market.

Jan 1, 2004