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By William Reisz

In our line of work,like many other professions, there may be times when circumstances or a series of events may arise, contributing toward unacceptable risk. When multiple parties are involved, there will almost inevitably be differences on how best to deal with these situations. Unless approached in an intelligent and these differences may often have the potential for costly and unexpected results.

Jan 1, 2014

By Steve Dillingham

The origin of the written blasting log or shot report can likely be traced back to the earliest annals of blasting and record keeping. These records were, for the most part, a way of checking inventory, production progress, or billing, and not necessarily designed with the intention of being used as a legal document in a court of law. As our litigious society has evolved to include far reaching regulatory requirements, however, the blasting log has developed to support and aid in the defense of the common blaster from blasting lawsuits by providing a comprehensive written report of his or her actions.

Jan 1, 2002

By P A. Lang, J G. Ayotte, R W. Humphries

Atomic Energy of Canada Limited (AECL) has the responsibility for research, and development of technologies, for the safe and permanent disposal of Canada's nuclear fuel wastes. As part of this comprehensive program, AECL is constructing an Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, to evaluate aspects of the concept of waste disposal deep in stable geological formations. No nuclear wastes will be used in the URL program.

Jan 1, 1986

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 James C. Irvine

Meramec Mining Company's Pea Ridge underground mine is presently involved in a large scale pillar recovery program and has made use of both rotary and down-the-hole drills for large diameter blastholes. Groups of pillars have been blasted with water gels in massive blasts which have broken in excess of one million tons of ore per blast. An outgrowth of the pillar recovery program is the combination of rotary and down-the-hole drills to develop vertical "raises" between mine levels. This paper outlines the Pea Ridge procedure for pillar blasting including the use of non-electric caps. Techniques and loading rates are discussed, and safeguards against blasting damage which were developed as a result of the program are presented.

Jan 1, 1976

By Greg Shapiro, Paul Dr. Worsey

Mining, quarry, and construction blasts are becoming more and more dependent on bench profiling. The use of accurate profiling gives the blaster better data for the most efficient blast results. So, we ask the question: What is the best method for measuring and analyzing burden?

Jan 1, 2019

By Gary Anderson, J. P. Remi Proulx

Rio Tinto’s Colowyo Coal Mine produces 2.1 million tons per year in northwest Colorado. Colowyo uses the terrace mining method to recover up to seven coal seams ranging in thickness from 5 to 20 feet. Coal recovery in the 6 foot thick high grade C-seam has recently been challenged due to large variations in the pitch and roll of the seam. As well, some coal damage was seen due to an increased thickness of the overburden consisting of a hard sandstone channel.

Jan 1, 2012

By Craig Wilbour, John Stimberis, Rob Gibson, Lee Redden

An avalanche is a snow slide. A simple explanation is that the snow on a slope will slide (avalanche) when the snow strength can no longer support its own weight. Snow avalanches happen when the load from snowfall or ram on a snow slope increases faster than the stre n g t h of the bonds between snow crystals. Avalanches can also happen when the strength of a buried layer decre a s e s . Active avalanche control is the intentional triggering of slides. Washington State Department of Tr a n s p o r t a t i o n (WSDOT), does avalanche control to minimize the chance of natural avalanches into traffic. Avalanche control work is done all over the world by: highway departments, ski resorts, railroads, mining operations, utility companies, and other activities threatened by avalanches. The majority of active avalanche control is done with skis, by explosives, or exploding projectiles. Blasting techniques and practices have evolved to fit the specific needs of avalanche contro l . Passive avalanche control is the use of engineered s t r u c t u res such as snow sheds, bridges, or snow supporting devices, to permanently protect a specific location from avalanches. The problem is that these struct u res are extremely expensive. There are a variety of passive avalanche control measures as well as the active m e a s u res used to protect the highway over Snoqualmie Pass. As traffic volume and use expectations incre a s e , m o re extensive passive measures will be needed to keep avalanches from affecting the highway.

Jan 1, 2004

By C Agreda

The Cushion Blasting Technique applied to solve the high risk case history represented by a 10,704 TM rock locate at 120 M from the hydroelectrical plants of 350 KV each, is described, analyzed and discussed. The generation and distribution of 700 KV produced by two hydroelectrical plants must not be interrupted by any reason, because the 26 district of the province of cajatambo, of the Lima department; would not have electrical power. The search of the best alternative and methodology, the drilling and blasting pattern calculations, charge design and loading, connections and initiations of the 50 blasts are described, analyzed and discussed. Finally, the excellent results from a technical, economical, enviromental and safety point of view of the 50 primary blasts are discussed and emphasized.

Jan 1, 2005

By Alyse Munro Hindley

The increasing negative public opinion toward blasting has led to stricter regulations and increased costs. This paper outlines alternative methods of rock excavation and the safety regulations and certification required by blasting professionals. Most importantly, however, it showcases the benefits and accomplishments that controlled blasting bring to society, giving the public a better understanding of the necessity of blasting in modern society.

Jan 1, 2015

By Patricio González Santis, Jacopo Seccatore

This paper documents drilling and blasting activities from gold mining in Ecuador and Chile. First, are described the outdated and often non-rational techniques employed by miners, to provide a general framework of the current methods. Then, it is shown what can be improved and how the current methods can be modified. Finally, are shown some field applications and the comparisons of the results obtained

Feb 1, 2020

By Carlos Campos Junior, Leonardo Soares Chaves, Raul Carretero Hoz, Renato Jacome Costa, Davi Bastos Martins de Oliveira

The Vale’s Serra Sul mine, also known as S11D project, is one of the world’s largest open pit iron ore mines, located in Brazil’s Amazon region. The mine produces around 90 Mt of high-quality iron ore annually. Its unique orebody enabled the S11D project to adopt a truckless mining system with In-Pit Crushing and Conveying (IPCCs) for ore exploitation and waste stripping. The IPCCs system requires crushing the waste, mainly composed by the jaspilite lithology, and is also conveyed to waste deposits several kilometers away from the mine. Due to Amazon’s environmental restrictions, the project was designed with preliminary geological knowledge, leading to the installation of primary crushers not designed for the hardest jaspilite, with uniaxial compressive strength (UCS) up to 500 MPa. This resulted in low waste crushing performance, affecting stripping ratio and threatening future production. A project was developed to improve the fragmentation of the jaspilite, allowing higher waste IPCC production, and reducing the risk to the production due to low performance of waste crushing and conveying. The first challenge was the independence of the geological and the geomechanical models, while only the geological model was considered in blast designs, the geomechanical model describes six waste groups of jaspilite classified according to their strength. A new geological model was then created to incorporate the geomechanical classification, allowing different blasting design according to the rock strength of the jaspilite. The blasting pattern on most compact jaspilite was reduced 27%, from 22m² to 16m² in 9 7/8” diameter holes, with a proposed theoretical reduction of 23% of the P80, from 326mm to 250mm. The second challenge was the implementation of the new design, as this pattern size and the high powder factor (2.9 kg/m3) were paradigms for such a large iron ore mine. The measured results have shown 25% reduction of the P80, the crushing rate was increased by 17% (230t/h), saving around $2.4 million annually in crushing and conveying system maintenance.

Jan 21, 2025

By Joshua Hoffman, Braden Lusk, Kyle Perry

Shock tubes are used to simulate large-scale arena explosions without the use of full-scale arena sites that utilize large quantities of explosives. Instead, small explosive charges can be used to drive shock tubes. When this is done, the geometries of the explosive charges can alter the resulting pressure time curve. A common geometry chosen for the explosive charge is a sphere in order to be congruent with the spherical shockwave that emanates symmetrically in three dimensions from the detonation point. This paper reports on the findings from experiments that study the effects of altering the charge geometries and explosive types while keeping the TNT equivalency constant. Peak pressures and durations were affected by these changes. Directional phenomena are exaggerated by the use of certain charge shapes and detonation points. The speed of the detonation front in the explosive being greater than the speed of the shockwave in air played a critical role in the resulting pressure time waveforms. Waveform manipulation can be used to generate job specific waveforms that ultimately benefit the shock tube operators and their clients.

Jan 1, 2010

By Ron J. Elliott, Dylan Wedgewood

A series of five signature holes were blasted at the Highvale Mine and the resultant seismic data was analyzed to make recommendations on how best to address neighbour complaints regarding blast vibrations. From an analysis of peak vibration levels measured at the closest neighbour for blasting during 2016, it was determined that the blast vibration intensity varied between 1.4 to 4.3 mm/sec (0.06-0.17 ins./sec.), well below the level of concern for the onset of minor damage to residential structures, however, the frequency of the blast vibrations was between 2.2 and 9.7 Hz, which is within the range of the natural resonant frequency for a single story home. This was determined to be the cause of the neighbour complaints, as the home would be responding to the blast vibrations.

Jan 1, 2018

By M Lemieux, R Mason

The SABREX blast modeling program was introduced to I.O.C.C.'s Carol Lake Iron Ore Project in December 1987. As part of CIL's Technical Services, SABREX was used to implement an optimization program designed to analyze and introduce various grades of MAGNAFRAC at a constant pattern while maintaining acceptable blast results.

Jan 1, 1989

By D. Scott Scovira, Remi Proulx

The Meikle Mine is a high grade, underground gold mine utilizing primary-secondary longhole open stoping with delayed backfill to produce 3000 stpd of ore. Hot and reactive ground conditions were encountered early on in the mine life. Ground temperatures up to 330” F were measured. In the early stages of mining, the mine experienced premature detonations using different explosives. The learning curve to safely mine this high-grade gold deposit in hot and severely reactive ground was indeed very steep. Currently, the Meikle Mine uses a special buffered bulk emulsion in all blasts to address hot and reactive ground concerns. In addition, exacting procedures are also followed to ensure safe work with explosives. The combination of new explosives technology and strict loading procedures permits high mine productivity with the highest degree of safety.

Jan 1, 2000

By Alastair Grogan, Ron Elliott, Dale MacLean

Blasting for armour stone presents many unique challenges. Often, blasters get themselves into trouble when they assume that they can simply modify a production blast design to produce the required fragmentation size. They bid on the project using typical production blasting costs, and then find that they cannot produce the required fragmentation size and quantity with an acceptable waste factor. This paper outlines industry best practice guidelines for the production of riprap or armour stone. The paper examines the importance of initial geological mapping to determine the average in-situ block size, and the advantages to be gained from working with the geology to maximize production of the required block sizes. The paper also outlines the importance of proper explosives selection as well as blast designs that are unique to the production of riprap. The paper reviews challenges and experiences realized from multiple projects in differing rock types.

By Sushil Bhandari, Amit Bhandari

Blast optimization in open-pit operations is a task that often remains at a theoretical stage. Indeed, when it comes to operational blast design and onsite implementation, time restrictions and field conditions make it difficult to execute a planned pattern accurately and optimization according to local conditions is even more difficult. For example, adjusting a drill pattern to a complex face geometry is not something that can be easily undertaken on site. Blasters and engineers will do their best trying to distribute boreholes over the bench and even then, it can take them hours to achieve an acceptable layout. Similar situations occur with delay sequences, when trying to adjust them to address selectivity or vibration issues. For these reasons, operational blast design will often remain at a very basic level and the required adjustments are laid aside due to the difficulty of implementing them on site.

Jan 1, 2019

By Robert Hopler

RBH Note: The Illinois Powder Manufacturing Company was established in 1907 and was acquired in 1957 by American Cyanamid. The latter company left the explosives business in 1969.

Jan 1, 2010

By Sérgio Augusto Ferreira, Alan Gerson Diaz Butron, Carlos E. Arroyo, Marcus Neves, Jorhs Enrique Casimiro Huayhua, Dieggo Santos, Eventomar Junior

The presence of natural underground cavities is normally a characteristic of iron ore deposits, specifically in tropical deposits. Brazil and the United States are the only countries that have a legislation to protect these structures, but in Brazil this legislation is very specific for the existing cavities in the federal territory. These cavities are classified by their level of relevance as high, medium, and low. From this perspective, its preservation becomes mandatory, especially, for those of high relevance in order to protect the species (flora and fauna) that live in them. When these structures are within the production phases, it becomes a challenge to exploit these reserves with the use of commercial explosives, since these structures condition and may restrict the use and amount of explosive charge. This paper presents the methodology of controlled blasting associated with predictability via realistic simulation in production polygons, applied in a Brazilian iron ore mine where there is a presence of high relevance natural cavities with restrictions in relation to the limits of Peak Particle Velocity (PPV), which is product of detonation.

Feb 6, 2023