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By Brian Wingfield, Rick Givens, Greg Williams

Many technological advancements have been made in explosive products and applications over the last 15 years resulting in productivity and cost gains. However, the applications of total energy (engine horsepower) in the majority of rotary drilling technology, has remained virtually unchanged over that period. While advancements have been made in components, efficiency, and types of hydraulic systems used on drills, the application of current hydraulic technology to improve drilling productivity has not been interactive with end users. This paper will investigate how traditional design assumptions, regarding typical application of horsepower in current rotary drill systems, can actually limit productivity.

Jan 1, 1996

By Valeri Mitkov

Studena Quarry is one of the main suppliers of inert materials for concretes production in Sofia. It is characterized by massif heterogeneity in density and fissuration. Failure to take into consideration this fact during the planning of the blasting works recently had unsatisfying results in their carrying out – obtaining of materials with too small dimensions or high percentage of outsize material. Series of test blasting were carried out to find the relations for calculation of the main parameters of the drilling and blasting works. The blasting network was enlarged to 6 x 6 m, the diameter of the shot-boreholes was changed from 110 to 152 mm, the stem of the boreholes was significantly reduced and the relative consumption of blasting agents as a whole was reduced to 0,37 ?g/m3.

Jan 1, 2010

By Lazar Kricak, Zoran Teodorovis, Dragan Bogunovic

Scattering of delay interval around nominal value is an important issue in blasting practice. The scatter interval, as becomes wider, increases a probability of time delay overlapping adjacent blastholes. An excessive flyrock, ground vibrations, air blast and poor fragmentation are the symptoms for scattering related problems. Utilization of the short delays in the blastholes and longer delays on the surface are recommended solution to overcome mentioned problems. In contrast to global trends manifested through the application of electronic detonators and non-electric shock tube systems, revitalization of inexpensive electric detonators in combination with an accurate initiation system may be an acceptable solution. An extensive work was carried out at the Blasting Center Laboratory at the College of Mining and Geology, University of Belgrade, to develop a precise initiation system. As a result, Sequential Blasting Initiation System – Radio Frequency (SBIS-RF) was developed. It is expected that this system will increase blasting productivity, and reduce negative environmental impacts and total blasting costs.

Jan 1, 2008

By Denis Rickman, Jon Windham, Stephen Akers, Byron Armstrong

The soil crater formed by detonation of an explosive charge is of considerable military interest because of the common use of explosives to create soil obstacles. The soil crater is also an important piece of forensic evidence for the investigation of terrorist bombings. With recent advances in numerical codes, modeling and simulation of explosively-formed soil craters is becoming an attractive means of analyzing this phenomenon. Consequently, the need exists to better understand the relationship between soil properties and the resultant soil crater. An extensive database has been developed for the case of explosives detonated in or above in-situ soils of various types. However, in most cases, the soil properties were either not adequately quantified or the soil materials themselves varied such that the gross properties were poorly understood. A research program is underway to improve methods of relating soil crater dimensions to soil identification properties such as USCS classification, particle-size distributions, and Atterberg limits, as well as to soil composition properties such as density, moisture content, and volumes of solids, water, and air. As part of this effort, both explosive detonations conducted over well-controlled and well-documented soil backfills and companion numerical simulations were studied. This paper presents an overview of the effort.

Jan 1, 2010

By Thomas E. Lobb, Harry C. Verakis

Blasting is a primary means of extracting minerals and ores at surface mining operations. The domestic consumption of explosives and blasting agents during the year 2001 was about 5.25 billion pounds. Flyrock is always a major concern for the blaster. Flyrock from surface blasting operations has caused serious injury and death to employees and other persons. Injuries due to flyrock and the lack of blast area security accounted for over two-thirds of all blasting-related injuries in surface coal, metal, and nonmetal mines during the period 1978-2002. Selected accidents due to flyrock and lack of blast area security in surface mining are presented in this paper. Incidents related to construction blasting are also described. Techniques to mitigate blasting accidents are discussed. These include proper blast design, driller-blaster communication, inspection prior to loading and firing the blast, removing employees from the blast area, controlling access to the blast area, and using a blasting shelter. An experienced driller could detect potential problem areas such as voids, mud seams, incompetent rocks, and other irregularities by observing the progress of drilling. The drill log should include the details of any unusual or exceptional circumstances noticed during drilling. A blaster may need to alter the loading configuration to alleviate potential problems. Basic blast design is sometimes taken for granted and assumed to be proper for the conditions encountered, but one size does not fit all. It is known from the physics of blasting that the explosive energy takes the path of least resistance. The path of least resistance could generate flyrock, depending on the blast site conditions. A combination of ‘borehole tracking’ and ‘laser profiling’ can assist in improving the design of a blast. The blaster can use these tools to adjust borehole loading to match site conditions.

Jan 1, 2004

By Thomas M. Keevin, Gregory L. Hempen

A user-friendly model for environmental effects from underwater explosions is presently available. The model by Munday et al. (1986) is effective for determining fish mortality radii from underwater shooting. The IBLAST program (Coastline Environmental Services 1986) from this model includes estimates for both borehole-loaded explosives for demolition or rock removal purposes and midwater shots. Midwater shots may be used for fish population assessments or some seismic surveys. The program produces approximate mortality distances for planning purposes. IBLAST does have serious shortcomings of which users should be aware.

Jan 1, 1995

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 Timothy D. Stark

Blasters are usually strictly liable for injury or damage caused by flyrock (trespassory invasion) and blast-induced vibrations (non-trespassory invasion). The application of strict liability to non-trespassory invasions has resulted in significant litigation that has hampered the use of blasting and the blasting industry. Stark (2002) proposes that blasters should not be held strictly liable for non-trespassory invasions but should be liable only if their conduct is proven to be negligent. This change in legal standard was proposed because improvements in blasting technology over the last thirty years allow blasting to be conducted without substantial risk of harm to property and thus the amount of harm imposed by a blast can be related to the level of care exercised by the blaster. It is anticipated that negligence standard will reduce the amount of litigation because a plaintiff will have a greater burden to overcome. To facilitate the acceptance of negligence standard by a court of law, this paper illustrates the application of the negligence and strict tort liability frameworks using actual cases in which a decision was rendered. It is evident from these cases that some of the successful claims under the strict liability framework would not have been successful, and probably not litigated, under a negligence framework, which could result in substantial cost savings to the blasting industry and consumers.

Jan 1, 2004

By Orica Chile, Orica Brasil, Orica Brasil Victor Morais, Kinross Paracatu Leopoldo Muñoz, Kinross Paracatu Luis Marinho, Gubio Barsottini, Orica Brasil José Vergara, Lucas Steffen, Orica Brasil Washington Vilas

In drill and blast activities, it has been a challenge to sculpt walls accordingly to what has been designed in state-of-art mining design software. Obviously, the perfection of making neat and smooth walls – using aggressive sources of energy, like explosives – are time-and-money consumable and, sometimes, even unnecessary. But undoubtedly, it is vital to guarantee solid walls, safe operations environment, beyond to avoid ore losses and pit constraints caused by poor rock breakage on detonation. Kinross Gold Corporation owns the biggest Brazilian Gold Mine, located in Minas Gerais state. Morro do Ouro mine has reached over 30 years of operation, and due its mature age, the complex has developed its pits, becoming them deeper and surrounded by high walls.

Feb 6, 2023

By Midori Sakamoto, Nobuaki Sakuma, Tsuyoshi Murashita

Recently, tunnel blasting works near the residential area and existing building are increasing and environmental problems caused by vibration have become serious public concern. In order to solve these problems, blasting works have been conducted with segmented blasting and reduce advance per round. However, with these blasting, work efficiency is not obtained, and regrettably the cost and risk of accident tend to increase. We developed a new controlled tunnel blasting technique with electronic delay detonator. Electronic delay detonator can supply extremely large range of delay period which could not be achieved with conventional pyrotechnical delay detonators. We utilized advantages in initiating hole by hole over entire tunnel face at the same round. Much seismic data obtained from tunnel blasting with conventional detonator was statistically analyzed in order to find average duration time of vibration caused by a single hole initiation. Numerical simulation using sample waves from a single hole initiation was carried out in order to find an optimum delay time which can separate vibration in each hole initiation and without decreasing blast performance. Trial blasting was conducted to examine the correctness of optimum delay time obtained from numerical simulation. This blasting technique was applied to an actual tunnel construction. This tunnel is 2 lane automobile tunnel with a total length of 659 meters and internal cross section of 70 square meters. The purpose of the use of blasting technique on occasion, was the protection of fresh water reservoirs directly above the tunnel, and to keep the effect on local private houses to a minimum. The vibration level against this station was limited under 20 mm/see P.V.V. With this blasting, the tunnel construction was completed without exceeding the limited vibration level, with minimum cost and construction time.

Jan 1, 1998

By U. Steiner

Electronic detonators have been in commercial use for a decade, with an excellent safety record. This paper lists known incidents involving electronic detonators. Typical standards required by regulatory bodies for static electricity and electromagnetic fields are reviewed. The performance of some detonators is compared to these standards; in general the minimum standards are easily exceeded. The general resistance of electronic detonators to extraneous electrical energy that can be derived from the body of test results is compared to danger levels for exposure of humans to these energies; it is shown that electronic detonators can safely tolerate higher electrical energies than people can. This comparison includes comparable data for electric detonators, which are shown to be more vulnerable to extraneous electrical energy than people are. Electronic detonators also bring significant safety benefits in blasting due to their testability, two-way communications, reliability, programmability and precision. The links between these attributes and enhanced safety are discussed with examples from actual blasting. Although electronic detonators are usually more vulnerable to extraneous electricity than non-electric initiation systems, the paper shows that the net safety benefit in handling and blasting is in favor of electronic detonators, which are the safest initiation system that has ever been offered to the mining industry.

Jan 1, 2010

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 Eric C. Gerst

"In this current era of soft commodity and coal prices the mining industry is turning towards optimizingall levels of production to reduce operating costs. Part of this trend includes the automation of miningmachines. As the first tier of the mining process blast hole drill automation offers benefits through the entire value stream from drill bench to material processing."

Jan 1, 2017

By B. Corrêa, M. Cavalcante

A large open pit iron ore mine in Brazil, which has a heterogeneous lithology, faces a challenge in defining drill and blast patterns to achieve the expected results. The mine needed to obtain an automated representation of the fragmentation curves and correlate them to the respective blasts, lithologies and quality parameters, seeking the continuous optimization of the fragmentation process and its benefits to the subsequent comminution processes. Trials were carried out for 5 months to demonstrate the functionality of an autonomous fragmentation monitoring system that analyzes the granulometric curve of the material throughout the muckpile and makes the results available online and in real time. The system, which contains a binocular camera, a processing unit and an antenna, was installed in a shovel, to evaluate the following KPI's: monitoring failures, monitoring capacity, physical availability and reportability of oversized boulders. The system analyzed 33,060 samples, with an average capacity of 285 photos every 24 hours, 127 during the day and 158 at night, all measured, analyzed, stored, and made available on its online platform, reporting 223 alerts of P80 above 400mm (15.7 in) and 38 particle sizes above 900mm (35.4 in). The inactive and operational hours of the monitoring system corresponded, respectively, to the idle and worked hours of the shovel, according to dispatch data. There were no camera or processor failures, and rain, dust or poor internet conditions did not impact sampling and fragmentation analysis, indicating 100% physical availability of the system. The autonomous monitoring analyzed 139 times more samples compared to the currently used manual method. In addition to increasing sampling representativeness and automating the process, it increases the safety, quality, and productivity of granulometric analysis, eliminating the exposure of people in the mine and human bias in the analyses. Additional analyses were performed by correlating digitally centralized drill and blast data, data from autonomous drills and fragmentation results. Automated obtention of granulometric curves favors quick decision-making and optimization of blasts to achieve better results in productivity and cost reduction in the plant and mine operation. The autonomous fragmentation monitoring system met the need presented by the mine, proving to be a key tool in continuous improvement projects, including Mine to Plant.

Jan 1, 2024

By Jesús V. Saccsa, Kenji B. Loayza, Erick M. Condori, Jorge A. Velásquez

This research investigates how to reduce manufacturing costs of a safety fuse composed of black powder, replacing its ingredient NO3K by NO3Na for processing, and contributing to minimize costs per blasting.

Jan 1, 2017

By Eduardo Lozano, Vilem Petr

The use of explosives brings countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition, and avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation.

Jan 1, 2017

By G G. Paine, C V. B Cunningham, G Harries

The companies of the ICI Explosives Group have successfully used a wide variety of internal computer codes including BOBCAT, KUZ-RAM, ICRAX, XPLODE, BLEND, 3CRACK, MICBLAST, DETON, etc. In recent years the extensive experiences across ICI have been combined into a single compatible model engineered to worldwide technical service and customer needs for the prediction and assessment of blast results.

Jan 1, 1987

By Abdulkadir Karadogan, Zikri Keti, Umit Ozer, Mehmet Aksoy, Ulku Kalayci

This paper presents an investigation about how the motions of blast induced vibration waves were affected by the presence of the fault planes. This study was carried out at Espey Open- Pit Boron (Colemanite) Mine in Turkey. Within the scope of the study, ground vibration components were measured for 8 shots using 9 vibration monitors, considering the direction of the fault. Measurement stations were located around the fault line that intersects the open-pit mine in the north-south direction and on different benches along the fault plane. Then, the data of the vibration components obtained from the 77 recorded events were analyzed and the results were presented.

Jan 1, 2012

By R Deshaise, B Mbhanty

The importance of controlling density of commercial explosives, and the various means to achieve it are described. m e field conditions responsible for density changes during blasting and their effect on blast results are examined. Understanding of the behaviour of density control ingredients such as gas bubbles, glass and plastic microballoons under pressure, is considered essential to predicting explosives performance. Both static and dynamic pressure effects have been studied for typical donor-receptor cartridge configurations. The amplitude and temporal characteristics of dynamic pressures inside receptor explosives have been studied by means of the underwater test, and guidelines developed to limit density changes due to external pressures.

Jan 1, 1989

By Daniel Roy, Chris J. Preston, Ron J. Elliott

This paper discusses the use of pressure transducers in water filled boreholes in conjunction with surface mounted geophones to gather field data for in-situ dynamic rock properties determinations. A high speed collector is used to capture the data in the field. The calculated P and S wave velocities and rock density measurements are used as input into the Blastcalc program where the values of Young`s Modulus and Poissons Ratio are calculated. The rock properties information is used along with geological structural data and explosives properties in a 3-D blast modelling program to calculate predicted fragmentation distribution and other blast performance criteria based on the proposed blast design.

Jan 1, 1996