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By William D. Hissem

For those blasthole applications which require the use of holes ranging from 1” to 5.5” in diameter, the use of top hammer drills has been the equipment of choice for several generations of drillers. Pneumatic compressed air and hydraulic compressed oil systems represent the primary technologies which are available to the drilling practitioner. While both employ the same operating principals, the characteristics of performance, cost, and reliability can be markedly different between technologies and manufacturers.

Jan 1, 1998

By Robert Hopler

As a part of the depression and rectification work on the Port Morris branch of the Harlem Division of the New York Central & Hudson River Railroad, a short tunnel is being driven under St. Mary’s Park. The park is near 149th St. and St. Ann’s Ave., in the Borough of the Bronx, New York City.

Jan 1, 2006

By Tom Barry, Kameron Ray, Dr. Gavin Yuill

Imerys Talc, Yellowstone Mine in Montana faces significant geotechnical challenges such as poor wall quality and local instabilities. These instabilities are driven primarily by the characteristics of the rock mass, but are aggravated by drilling and blasting operations.

Jan 1, 2016

By Eraldo Florêncio, Paulo Couceiro, Manuel Lopez Cano

Specialized marine blasting techniques were required to deepen and widen the access channel and turning basin of the Sudeste Port Terminal in Rio de Janeiro, Brazil. This terminal has been designed to handle the exports of iron ore and other bulk solid cargoes to international markets. The Sudeste Port Terminal is connected to the iron ore quadrangle in Minas Gerais State by a dedicated railway line, giving Brazil’s independent miners a seamless access to global markets. However, the Sudeste Port Project is located in a protected marine environment. Blasting in this area has required a comprehensive blast induced ground vibrations monitoring and analysis program to ensure the safety of the sensitive structures surrounding of the blast areas. Nevertheless, the risk of generating higher ground vibrations on nearby structures due to the combination of short distances, larger excavations layers and complex geology, increased the complexity of the blast due to the limitations imposed by the maximum instantaneous charge and a demanding project schedule. Site-specific test blast programs were planned and executed in order to obtain in-situ vibration data to establish the local attenuation law, and also to better understand the role of dominant frequencies before production blasting started. This paper summarizes the main findings and solutions applied during the marine blasting project in the Sudeste Port Project.

Jan 1, 2018

By James W. Reil, Douglas A. Anderson, Steven L. Burchell

A total of 26 full-scale production blasts at three sites were extensively monitored with sophisticated instrumentation systems to determine the benefits of "ore. accurate detonators. The new and "ore accurate MS electric Masterdet detonator was tested against conventional detonators to determine any increase in productivity outputs. All blast design parameters between paired blasts were kept as constant as possible with the only difference being the inherent accuracy of both detonator systems.

Jan 1, 1989

By Carl Hendricks

Aquila Mining Systems Ltd., is the world leader in drill monitoring, control and GPS-based machine navigation systems for the mining industry. This paper will review the design and application of AQUILA’s drill monitoring, control and positioning systems currently in use throughout the world and some of the benefits that derive through their use. In 1993, AQUILA became the first company to install a high precision, cm level, real-time GPS receiver on a blasthole drill. In fact, this was likely the first application of GPS on any form of production mining equipment. To date, AQUILA has installed over 90 GPS based drill monitoring systems worldwide. Since 1992 AQUILA has continued to lead in the advancement of new technologies for drilling including real-time geology recognition and automated drilling control systems. The AQUILA DMseries drill systems offer mines the ability to collect and transmit to the mine office; drill production statistics, ore and waste intersections, exact collar elevations, hole positions and depths, maintenance information and consumables tracking. Unique office software developed by AQUILA provides an encompassing Windows environment within which to manage and coordinate all aspects of data communications and information management between the drills and various mine departments. AQUILA and Caterpillar, along with Mincom and Trimble Navigation are partners in a technology alliance that is providing the surface mining industry with vehicle tracking and navigation systems for all mobile production equipment.

Jan 1, 2000

By Marwan M. Mohammed, Hani S. Mitri, Wilfrid Comeaul, Baoyao Tang

In many parts of the world, rockbursts have become a major problem of mining at depth. As orebodies are being mined deeper, rockburst phenomena have become familiar to deep hard rock mines. Rockbursts are generally characterised by sudden release of energy in a volume of highly stressed rock, which can cause local violent failure of the rock mass around the opening. One method of controlling these failures is to precondition the rock mass by detonating fully confined explosive charges at the appropriate locations. This method known as destress blasting, was first tried in the deep South African gold mines (Roux et al., 1957), and was widely used later in Canada, United States, France, Poland and Japan.

Jan 1, 1999

By Sanna Mustonen, Seppo Mellanen, Mellanen, Pekka Kantia

In Finland Posiva Oy (Company) is responsible for implementing the final disposal programme for spent nuclear fuel of its owners. Company is preparing for the geological disposal in Olkiluoto crystalline bedrock. Excavation will be executed using drill and blast method. Method unavoidably causes variable excavation damaged zone (EDZ) on tunnel surfaces. The EDZ constitutes a risk for long term safety and therefore good control methodology of the blasting technique is required. The thicker the EDZ, the greater is the likelihood for detrimental transport pathways for ground water to transport radio nuclides, should those be present.

Jan 1, 2016

By Michael D. McGill

The effect of fragmentation size distribution as it relates to front end loader productivity was evaluated by comparing loader cycle times to fragmentation size of the shot rock. At Gold Mine in Southern Utah, a gold deposit containing both limestone and sandstone formations were blasted in the same shot.

Jan 1, 1994

By Paulo José Costa Couceiro Junior, Manuel Lopez Cano

In 2011, two historic outcrop rocks known as Teffé and Itapema located in the navigation channel of the Port of Santos, Brazil (Latin America’s largest port) – were excavated by drilling and blasting techniques. Sensitive structures - a passenger terminal and an 80-year old warehouse were exposed to ground vibrations generated by underwater blasting. The warehouse had existing structural problems due to a combination of factors such as the presence of an unstable soil, previous repair work, and intense seismic events generated by the daily traffic of cargo trains nearby during eight decades. Since the worsening state of the structure was attributed to ground vibration from underwater blasting, particle velocity time histories generated by underwater blasting and by passing trains were monitored. By analyzing the energy spectral density of these events using spectrograms, it was possible to observe the seismic energy levels in time and spectral domains. Since the hysteretic energy dissipation by structures is related to the duration of the seismic event and the limited dissipation capacity of the structure, one could expect damages to appear in the structure once energy levels exceeded this dissipation capacity. As the quantity of energy transmitted to the structure is proportional to the duration of the seismic event, the transmission of seismic energy to the warehouse structure over time was more significant in the case of the train-induced ground vibrations (several minutes) than those generated by the underwater blasting (few seconds). Thus, for the warehouse, train-induced ground vibrations have a larger impact on the structure rather than ground vibration generated by controlled underwater blasting techniques.

Jan 1, 2016

By Türker Hüdaverdi, Özge Akyildiz

"In this research, image analysis technique, Kuz-Ram and KCO Models were used to examineefficiency of the quarry blasts. Investigations were performed in Cendere region, Istanbul. As a firststep, image analysis software was used to determine particle size distribution of muckpiles.Additionally, the results of KuzRam and KCO fragmentation models were compared to the results ofthe image analysis technique. The efficiency of KuzRam and KCO models was investigated and theimportant points to be considered were explained. Additionally, the effect of the rock factor valueson the size distribution curves was investigated. The blasthole diameter is 89 mm. (3.5 in) in thestudied quarry. Each measured blast has a different burden, spacing and stemming length. Blastholes was drilled in a staggered pattern. It is concluded that, KuzRam and KCO models can be successfully used to determine fragment size distribution in Cendere Region Quarries, Istanbul. Site engineers can predict blast fragmentation using the theoretical fragmentation models and they may change blast design parameters before blasting operation if necessary. It is possible to calibrate the Kuz-Ram and KCO fragmentation models using the measurements obtained by image analysis technique."

Jan 1, 2016

By M. Hokkanen, M. Hagfors

The Finnish Defence Forces has destroyed old and spoilt munitions in open surface mass detonations at Hukkakero fell in municipality of Kittilä, Lapland, since 1988. The technique was learned from Sweden. The destruction camp is organized every year at autumn and it lasts 4-5 weeks. During the disposal period one or two charges are exploded per day. The gross weight of a typical charge varies from 150-250 tons including 15-25 tons of explosives. They mainly consist of TNT, but may also contain smaller amounts of amatol and hexotol. As a booster there have been used 2-3 tons of emulsion explosives.

Jan 1, 2015

By Rufus Flinchum

Two of the most critical concerns a blaster faces today are airblast and flyrock. Airblast, sometimes called noise or overpressure, can cause damage to neighboring structures, especially windows. It also is the cause for many vibration complaints. The human sense of hearing is often more acute to identifying source than the sense of touch. When a blast occurs, the airblast is what identifies the event. The vibration that may be felt is then associated with the airblast. Vibrations of greater magnitude, such as passing trucks or construction work on the house, go unnoticed because their sounds are familiar or expected. Flyrock is the number one killer and cause of damage. Elasting laws provide limits for these two concerns. Failure to comply may result in fines, closing of the operation, and even prison. Airblast and flyrock originate from two distinct areas, the open face and the bench surface. Each of these areas is addressed in the detailed proven procedures that follow, and if used by the blaster in conjunction with his own blasting knowledge, a sound blasting plan can be developed to minimize the occurrence of airblast and flyrock.

Jan 1, 1992

By Randall M. Wheeler

Many of us have used a seismograph to measure peak particle velocity and frequency. But do we really understand why? Also, why do we measure particle velocity instead of displacement and/or acceleration? What is the vector sum? How do these items relate? Where does frequency fit in? This workshop will attempt to answer these and other questions. Some of the answers may surprise you, others may not.

Jan 1, 1997

By Jorge Cárdenas, Alejandro Luna

In mining simulation for fragmentation results prediction is of utmost importance to study feasibility, ensure safety, and estimate the correct use of resources in drilling an explosive to meet requirements and avoid excessive usage. One critical case is fragmentation prediction, developed through models. Developing a fragmentation model in a mining unit aims to control blasting results to align theoretical and real data and improve correlation. Therefore, it is essential to collect post-blast fragmentation data, organize it, and systematically process it to develop a suitable model that meets variable requirements. Using a robust system of equations, this model should generate the required results with minimal variability between simulation and actual results. Additionally, this model must be adaptive to reduce this variability. Studying the most known and used models in mining resulted in our work correlating Cunningham 2006, Swebrec, and CZM models. Thus, the Simfrag model was created, presenting a robust foundation and combining the most notable advantages of the aforementioned models.

Jan 21, 2025

By A Tawadrous, P D. Katsabanis, S Kim

A series of small scale tests, have been performed to establish the effect of powder factor and initiation timing on the grindability of rocks. The blasts were performed in high quality granite blocks, which were cut from stone prepared by dimensional stone quarry operations. Three different types of granite, Barre, Stanstead and Laurentian, were tested. The charge consisted of detonating cord placed in five holes with water as a coupling medium, or concentrated charges of equal mass of high exolosive, fully stemmed or air decked. Powder factor was varied from 0.39 to 1.17 kg/m3. Charges were detonated simultaneously or with a small delay and in some experiments, detonation waves collided in the middle of each borehole. All fragments were collected and screened, and drop weight impact tests were performed on selected size fractions, using different levels of impact energy, to calculate the resistance of the rock to impact breakage. The work index of some of the blasted samples was measured using standard Bond mill grindability tests. The experiments generally showed increased softening of the rock with powder factor, manifested by the increasing initial slope of the relationship between t10 and impact energy. The rate of change of the initial slope decreased with increasing powder factor. Changes in the work index were small and consistent in trend with the results of the single fragment impact characterization tests. Charge configuration, timing as well as in-hole collisions of detonation waves affected the initial fragmentation but had little effect on the impact breakage of the samples.

Jan 1, 2009

By P J. Hommert, D S. Preece

"Commercial development of the United States Oil Shale reserve will require substantial amounts of mining. In fact, even a modest 500,000 barrels per day industry requires a mining effort equivalent to nearly half of the current U.S. coal mining industry. Obviously, mining efforts on this scale will benefit from technological advances. There are a number of areas where advanced technology could impact mining. These include continuous miners, shale transport systems, and blasting. This paperexamines recent developments in computer modeling of blasting and assesses the likelihood of these advances being applied to practical oil shale mining problems."

Jan 1, 1989

By Derek T. Novotny

Blasting cap precision is of major importance to advanced blast design. New technologies have introduced the use of microchips within detonator casings in the hope that the electronic control of the timing element will increase the accuracy of the cap and therefore improve the results of perimeter control blasting applications. The electronic detonators have proven to be accurate in timing tests done to date. They boast cap scatter results to microsecond accuracy, but the question is, does this degree of accuracy actually prove to be beneficial during practical use in the industry, or are conventional technologies applicable.

Jan 1, 1998

By Gerald W. Longenecker

For decades, traditional hydraulic engineering approaches have been used for sizing stream channels when stream relocation efforts have been necessary to allow for the advancement of quarry and other surface mining operations. These approaches have been based on various ydraulic models to design channel cross sections and slopes that could pass the required regulatory design storm such as the 2-, 5, lo-, 25-, 50-, or even loo-year events. Designing the stream channel to handle these more extreme ,storm events would often lead to large channel designs which required extensive bank and channel bottom stabilization techniques including concrete, rip rap, gabions, or other expensive approaches. The constructed channels often required ongoing maintenance to remove accumulated sediment and other debris which would settle out and reduce the hydraulic capacity of the channel.

Jan 1, 1998

By Carl Lubbe, Ron Frye

Numerous articles have been written regarding the effects of blast control plugs in an attempt to quantify stemming ejection rates, air overpressures, fragmentation’and other parameters measured using these devices. In an effort to further attempt to understand the function of these devices, field and laboratory research conducted with various stemming devices was performed to enhance existing data sets and analyze otherphenomena that occur when these products are used.

Jan 1, 1998