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By L C. Taylor

Very small scale testing has been shown to be able to predict quite accurately, in many situations, the results of full scale testing. Small scale tests are more cost efficient, easily observed, and easily instrumented than full scale tests. Over the past 10 years small scale testing in the Dynamic Effects Laboratory at the University of Maryland has been used to successfully study the response of structures and soils to explosive detonation. Small scale testing has been successfully used to predict full scale results in underwater cratering and channeling, the loading (both pressures and impulse) on vehicles due to the detonation of buried charges, the positive effects of bottom shaping for military vehicles to reduce this loading, and the movement of obstacles underwater by explosive charges.

Jan 1, 2012

By Jacqueline Berendzen

Summer internships are a great way for students to explore different career paths in the industry and get first hand experiences with potential employers. As a junior in mining and explosive engineering, my 2009 summer internship gave me a behind the scenes view of the actual workings of an explosive company and the role they play in the mining industry.

Jan 1, 2010

By Nikolaos Petropoulos, Ulf Nyberg, Ulf Stenman, Daniel Johansson, Håkan Schunnesson

The optimization of the explosive performance is of great importance since blasting is extensively used in civil projects and mining industry. An improved understanding of how the energy from the detonation of an explosive is transmitted to the surrounding rock mass is critical information for the proper selection of an explosive. Therefore, an extensive study was done on the influence of the blasthole diameter on the Velocity of Detonation (VoD) and the detonation front curvature.

Feb 1, 2020

By J. Schoonover, A. Moore

In the explosives industry, individuals face a multitude of hazards while working in mines, quarries, and construction sites. Safety becomes an ever-present driver as companies attempt to control costs, promote quality service and products, and grow business all while ensuring employees return home safely every day. One of the most challenging hazards that threatens the goal of absolute safety is flyrock. Ensuring that a blast does not result in rock leaving the blast area, thereby creating a danger for personnel in the vicinity, can be complicated due to the multitude of factors. Shot design, geology, operational procedures/techniques, explosive products, security plans, communication methods, and drilling practices can all adversely affect the safety of individuals helping execute a blast through an increased risk of flyrock. Flyrock can also pose a major threat to the public and other non-blasting personnel in proximity. Like many other industries encountering various challenging hazards, the explosives industry has recently adopted innovative technologies to help mitigate the risk of complex hazards such as flyrock. Specific applications of Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, employed in the explosives industry can help reduce the likelihood and severity of a flyrock incident. This paper explores a case study and theories of how the integration of drone technology within blast security plans, mine planning, blast design, design auditing, and blast area clearance procedures can help to decrease the risk of a flyrock event through the provision of data and information previously unavailable. Multiple opportunities exist during a blasting operation to gather data using drone technology. It is these data-gathering opportunities that can be leveraged to be maximally equipped for the mitigation of flyrock. Better data from drones can be sourced and used in security plans and clearance measures as well as utilized during mine planning and blast design. Increases in the quality and quantity of information during these crucial steps of blasting has proven to be an effective way to increase the peace of mind for explosive end users. This peace of mind, along with design flexibility and adherence to performance, is why the integration and utilization of drone technology is key for effective flyrock risk reduction

Jan 1, 2024

By Greg Quinn

After a long week of work in Colorado Springs this past July, I was looking forward to flying home to start a long anticipated family vacation. As I grabbed my seat on the plane, a man sitting next to me innocently inquired, to the row as a whole and not to me in particular, “I wonder what the weather will be like in Phoenix”? To most people, this is a common (maybe the most common) topic of casual conversation. To a meteorologist that just dealt with six thunderstorm delays at a major golf event over 4 days, well, lets just say the smirk on my face said it all. After giving my flight mate a detailed forecast and a short explanation on why I would know such information, I sensed, correctly, the inevitable follow up question was coming. “Why would you need a meteorologist at a golf tournament?”

Jan 1, 2012

By Jorge Cárdenas, Gustavo Huerta, Regina Rocha Oriundo, Miguel Angel Humpire, Johan Salas Flores

Currently a critical activity for slopes stability and safety in mining is pre-split blasting to reduce damage from trim blast. Most common explosive used are based on packaged explosives, with 1 ½ in diameter cartridges initiated by detonating cord. Traditional loading process requires a significant amount of trained personnel, which in our application context could take up to 20 blasters. When pre-split blast is scheduled, it usually reduces the availability of the blasters on the total loading services at site which are also demanded to have production blasting ready at same 12-hour shift daylight time.

Feb 6, 2023

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 Bjoern R. Petterson, Lars Haakon Siem

The world's longest highway-tunnel -- the Aurland Tunnel in western Norway -- is scheduled to be opened in the year 2000. A project to build a main highway between Oslo and Bergen with no ferry connections was approved by the Norwegian Parliament in January 1995. Construction of the five-year blasting project was started by the Norwegian Highway Authority in mid-March 1995, with an expected completion date of November-December 1999.

Jan 1, 1996

By Milos J. Bila

I would like to discuss today several safety topics that we at Nobel feel are going to be particularly critical to all of us who are involved in the manufacturing, transportation, storage and use of commercial explosives during the '90s. My purpose is to identify these topics in order to allow those in the commercial explosives community to better understand the potential difficulties we face.

Jan 1, 1992

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 Thierry Bernard

Since the signature hole method principle has been described in the 80's, there has always been a lot of controversy about it. The theory is easy to understand but when it comes to apply it for predicting vibration level, optimizing timing to reduce PPV or shifting frequencies, it’s not always working as expected. Simulations show waveforms that don't make any sense or predictions that are far away from actual results.

Jan 1, 2012

By Jim Peterson, Ricardo Freire, Mason Biernat

Variable nature of rock and face conditions, varying execution and changing nature of blasting are making ongoing optimization challenging. Intelligent planning and on-going analytics are required to mitigate variability and convert blasting into a predictable outcome by use of technology. Blasting operations generate a huge amount of data which can be used intelligently for optimization. In this paper, details are provided of a system which is used for blasting data collection in the field – Key details around blast parameters, explosives, initiating system details, video, photographs, vibration and fragmentation are collected in a cloud-based platform. Data can also be collected through a mobility device in the field (even without internet connectivity) and synchronized with cloud-based system. Also, data from various sources can be imported in excel formats in the software including from upstream and downstream processes from blasting. App also gives indication about exceeding of vibration, air blast overpressure, fragment size etc. Thus, making it possible to perform QA-QC before charging and deciding initiation timing and sequence at the blasting site. The data can be processed and analyzed to spot trends, help predict events, and formulate strategies at the design and execution stage. Data gathering of blast parameters, explosive used processing and analysis can be used to optimize operational efficiency, improve safety and environmental controls.

Jan 1, 2019

By Ulf Nyberg, Changping Yi, Daniel Johansson, Håkan Schunnesson

To investigate the non-ideal detonation properties of aluminized emulsion explosive, a series of tests for an emulsion explosive with 5% aluminum powder additive were carried out with mortar confinement. The velocity of detonation (VoD) and the curvature of the detonation front for different charge diameters were obtained from the tests with a high-speed camera. The burning process of the aluminized emulsion explosive has been modelled with the ignition and growth (I&G) flow model in the LS-DYNA code. A routine based on the optimization program LS-OPT code was developed to identify the parameters in the burning rate function with the detonation velocities and the front curvature radii from two tests. A Perl code was implemented in the routine and was used to calculate the VoD, fit the detonation front and obtain the detonation front curvature radii. The calibrated parameters were used to predict the VoDs and the detonation front curvature radii for the rest cases. The results indicate that both the VoDs and the detonation front curvature radii from the numerical modelling are in good agreement with the experimental results. The numerical results also indicate that the variety of the burn fraction and the peak pressure with the change of charge diameters is reasonable with the calibrated parameters.

By Ulf Nyberg, Changping Yi, Daniel Johansson, Håkan Schunnesson

To investigate the non-ideal detonation properties of aluminized emulsion explosive, a series of tests for an emulsion explosive with 5% aluminum powder additive were carried out with mortar confinement. The velocity of detonation (VoD) and the curvature of the detonation front for different charge diameters were obtained from the tests with a high-speed camera

Feb 1, 2020

By Dale Ramsey

As someone who has enjoyed photography as a hobby for many years, aerial photography to me has always been an exciting way to give a different perspective to my images. Our industry is always in search of new technology for bet­ter and more cost effective methods to improve our trade and aerial photography is a great tool to improve project planning or document its progress. It has typically involved conventional aircraft both fixed wing and helicopters but neither method is always available or cost effective. The lat­est innovation since digital imaging is the development of Unmanned Aerial Vehicles (UAVs) or drones. But there is a lot of uncertainty with this amazing new technology’s fu­ture in the U.S. as the Federal Aviation Administration (FAA) is under review and development of UAV regulations for commercial use which are slated to be completed in 2015.

Jan 1, 2015

By C. Zuniga, S. Combrinck, C. Peters

Agnico Eagle Gold have partnered with Enaex Australia at their Fosterville gold mine to leverage a combination of drill and blast technologies to optimise underground development mining. The mine is the first site globally to collaboratively develop and trial Enaex SWIFT electronic development detonators, which utilise a novel approach to the user interface, simplifying implementation and enabling the benefits of electronic initiation without the complexity of a conventional system. This has been combined with the use of a Sandvik 422i smart jumbo, and the Enaex underground emulsion charging unit with the capability to tailor the delivery of explosives as required and report on a hole-by-hole basis. The combination of these technologies enables full engineering oversight of the development cycle, in turn enabling optimisation of this process in a historically conservative application. The methodology for leveraging these technologies is to bore a controlled and defined blast pattern through using a smart jumbo, load the blast holes utilising lace loading to deliver a desired quantity of ammonium nitrate emulsion per hole, with the ability to reduce chargeweight for perimeter control, and utilising Enaex SWIFT electronic detonators with flexible template type pre-defined delays to initiate the blast holes. Subsequent to firing and excavation the performance of the blast in fragmentation, advance efficiency, and overbreak and underbreak is measured and reviewed. This is then used to optimise the development cycle and apply to other parts of the mine.

Feb 6, 2023

By J P. Tidman, I J. Kirby, G H. Harries

The SABREX computer model is based on the fact that both shock waves and gas pressure are important in describing a blast. The treatment of explosive-rock interactions includes the influence of non-ideal detonation to make use of recent advances in that field. Details of the blast layout are defined from a comprehensive list of conditions the blaster can control (drill pattern, charging and hook-up). The program gives practical and graphic information about fragmentation, muckpile, damage and costs.

Jan 1, 1987

By Stephen Mansfield, Nathan West, El Khalil Seyed

In October 2017, a multi-bench failure occurred in the east wall of the Guelb Moghrein copper and gold mine in Mauritania. The failure extended 100 m (328 ft) vertically and horizontally and resulted in the sterilisation of ore, but no equipment or personnel were put in danger. The remediation plan successfully removed the failed material and the cutback resumed to a modified pit design, leaving ore reserves behind. In 2021 after completion of mining in another part of the pit, a plan was formulated to develop a narrow cutback behind the failed wall and recover the sterilised ore. Infill drilling defined a resource of approximately 2.9 Mtonne (3.2 Mton) of ore at 0.78% Cu and 0.67 g/t Au at a strip ratio of 5.5:1. The high strip ratio meant that it was necessary to mine thirteen benches of waste, or 156 m (512 ft) vertically, over a two-year period before reaching the first ore, with the cutback only being economically viable if all ore could be depleted at the end of the third year. The high economic risk of the project required a holistic approach to mitigate the risk of another wall failure, by addressing the following areas: 1. Pit Design: with help from an external Geotechnical Consultant, the pit design was optimised to include increased factors of safety, reduced stress points, lower overall slope angles and straight lined walls were replaced with curved walls. 2. Geotechnical Management: the site Geotechnical Superintendent worked closely with an external Geotechnical Consultant to better understand the structural geology. Slope monitoring was improved through an expanded network of prisms, regular in field inspections and the use of a slope monitoring radar. 3. Drill and Blast: new drill and blast designs were developed from first principles, consisting of production, wall control and presplit designs. Blast master polygons and bench development sequences were developed with consideration of the structural geology and the influence of the initiation designs. 4. Mine Operations: improving operational discipline was a critical factor that ensured the accurate execution of drill and blast designs and excavation to bench levels and pit limits. This holistic approach has enabled the safe development of the cutback down to the 936 RL (relative level), two benches below the point at which the previous wall failure occurred. Extraction of ore has occurred from the 960 RL, and due to faster than planned excavation rates, the cutback is expected to be completed ahead of schedule.

Jan 21, 2025

By Paul L. Matrin

This paper will discuss the recent and on-going drill and blast optimization measures at the Sparkhule Limestone Quarry, which have resulted in a 44% reduction of drill and blast unit costs per ton of broken limestone. This amounts to approximately $240,000 of drill and blast saving per year at current annual production rates of about 2.5 million tons (2.3 million tonnes) total material shot. The reduction of drill and blast costs were accomplished by a detailed and controlled in-the-mine drill/blast experimentation and cost evaluation using 8 different blast pattern designs and shots totaling approximately 267,000 tons (242,200 tonnes) of shot and mucked material. A careful review of the geology of the deposit was performed to determine the different rock classification/strengths/structural properties and to adjust blast designs to optimize fragmentation for the different rock types. Equipment loading productivity and crusher throughput performance were monitored as part of the evaluation process to assure that an optimal fragmentation of broken rock was achieved with the new blast designs. The study included the review of bulk explosive and accessory selection criteria (ammonia nitrate/fuel oil mix - ANFO, mini prills (high density ANFO), sensitized and un-sensitized emulsions at a 30% emulsion/70% ANFO blend), blast pattern design, charge diameter and the cost of drilling. Laser profiling technology was used to assure proper bench heights, stemming and sub-drill footage and front row burdens. High speed photography, video and still photos were taken of the different designed shots to assist in the evaluation of the performance of each blast. Powder density checks, size distribution, back break, detonation velocity and pressure measurements were taken. Different borehole diameters were used for the drill optimization study and drilling cost and productivities determined. A detailed cost comparison between in-house blasting and complete shot service was prepared to evaluate if shot service is a cost effective alternative to current in-house loading and blasting including a review of the new and pending United States Bureau of Alcohol, Tobacco and Fire Arms (ATF) regulations and associated owner costs/risks and potential benefit of shot service.

Jan 1, 2004

By L. M. Lopez, J. A. Sanchidrian

This work investigates the performance of some of the measurement techniques used in vibrations from blasting monitoring. Two tri-axial geophones with cases of different size, shape and mass were tested in a shaker table. The geophone cases were mounted in three different ways on a granite slab fixed to the plate of the shaker: freely placed, sandbagged, and anchored. A known horizontal periodic motion of constant amplitude, and frequency from 16 to 200 Hz, was applied to the slab. Two amplitude levels of 5 and 20 mm/s (0.2 and 0.79 in/s) were applied when the sensors were sandbagged or anchored and only 5 mm/s when no holding force was applied. The transmissibility of vibrations from the rock to the longitudinal geophone as function of the frequency (i.e. ratio of response of the geophone to the slab motion) has been obtained for each measuring condition tested. The transmissibility is considered a composition of the transmissibility of the rock-to-sensor coupling and the transmissibility of the sensor’s mechanics and electronics. The transmissibility of the coupling is obtained normalizing the total transmissibility with the transmissibility of the seismographs, obtained by a suitable test to which a coupling transmissibility of 1 is assigned. Geophone-to-rock coupling is a resonant phenomenon that may alter the amplitude of the measured waveforms by a factor of 1.2 to less than 0.6. The most accurate and precise measurements are obtained with geophones anchored to rock. On the contrary, freely placed or sandbagged sensors are non-predictable planting conditions that lead to high amplification or damping in most of the frequency band analyzed. It is also shown that existing acceleration criteria to select coupling methods do not necessary lead to good quality (accurate and precise) vibration data.

Jan 1, 2014