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By Daodu Opeyemi

This paper describes several damages of blasting operations on some case studies, analyzes causative factors, and emphasizes preventive measures. Due to several complaints from some host mining communities as a result of blasting operations; two quarries from Nigeria suburbs were visited for study. The blasting design parameters in the mining companies were examined. Also, the history and existing conclusion of the neighboring buildings were studied using structured questionnaire, personal contact and visual examination. From the study carried out, it was discovered that varying negative environmental and socio economic problems resulted from the effects of vibration and flyrock on the nearby agro mining communities. The consequences are not limited to distortion of landscape but also include extinction of some animals, poor agricultural productivity; such as damages to economic trees and reduction in the yield of crops, health problems as a result of shock resulting to psychological disturbances, communal conflicts, blast induced cracks of structures and sometimes total collapse of host agro mining buildings, thus indicating that most mines did not comply with the safety concept of the existing environmental laws and regulations. Based on the results of the study it was recommended that proper blast design of quarries/mines should be conducted and the compulsory use of seismograph will be crucial in developing predictions. Environmental impact assessment should always be conducted before, during and after each blasting operation. Other possible control of vibration, flyrock and airblast, are also discussed in the paper

Jan 1, 2009

By Weiying Zeng, Shouwei Wang, Jinbei Zhong, Xiangdong Meng, Lingtian Meng

"Due to a drainage problem, the Lanzhou to Chongqing high-speed rail line had been out of service during the 2015 wet season, so a drainage tunnel is to be constructed for the line and required to be accomplished before the 2016 wet season. This drainage tunnel is only 5 meters below the line which is in service, therefore blasting vibration needs to be strictly controlled. This paper introduces all theapplied blasting methods, parameters and detonation throughout the entire project, finally bringing in the electronic detonator stagger phase technique and corresponding time difference for detonation."

Jan 1, 2017

By Steve Kane

Lightning is a very real problem in the surface mining industry. Today, as adverse market conditions continue to influence the surface coal industry, it has become necessary that all functions of the surface mining process become as efficient as possible. High production with reduced manpower is the winning combination of staying competitive in the market place. We at AMAX Coal are committed to staying in the coal business, but we have always been committed to providing a safe work environment for our people and will continue to do so in the future. Approximately two years ago, our Midwest mines installed state of the art lightning detection and warning systems at our mines. This paper will cover its application at Delta Mine; the benefits and problems encountered, and the impact this system has had on Delta Mine.

Jan 1, 1992

By Donald Wagstaff, D. Scott Scovire

The Coeur Rochester Mine is the largest primary silver surface mine in North America. Throughout its 17-year life, gold and silver grades leaving the tertiary crusher have typically been, on average, slightly below the mined bench grades as determined by blast hole assays. On a project-to-date basis, this grade variance is well within industry standards. While these variances are acceptable, mine personnel continue to study ways to further minimize the grade differences. One suspected cause for lower than expected head grades are ore loss and dilution resulting from blast-induced shot movement. In regard to grade control, the underlying design principle for non-electric blasts is the generation of uniform movement of the blasted rock material. Using one or two uniform directions of initiation, ore control methods at Rochester currently include adjusting flag lines on the muckpile in an attempt to account for displacement from original, pre-blast locations. To improve upon standard non-electric blasting practices, a series of evaluation blasts using an electronic initiation system (Orica i-konTM) was conducted in the summer of 2002. The primary objective of the evaluation blasts was to design shots that would segregate the ore and waste blocks into distinct muckpiles. Due to surface delay burning front limitations, truly effective ore and waste segregation blasting is difficult to accomplish with non-electric initiation systems for all but the most basic of ore geometries. The electronic detonator evaluation blasts produced visible boundaries in post blast muckpiles, identified by troughs or low areas, that closely matched the actual locations of pre-blast ore control flag lines based on blast hole assays. By blasting the ore and waste into distinguishable piles that were flagged and excavated accordingly, it is believed that blast-induced ore loss and dilution was reduced.

Jan 1, 2004

By Joseph Indeck, Seokbin Lim, Andrew Thompson

In the design of explosively driven penetration devices, understanding the impact conditions between the explosively propelled penetrator and the target is one of the most important steps in optimizing the performance of the device. These impact conditions are especially prevalent when a shaped charge jet impacts concrete, which is not an ideal target material. The specific impact conditions, including but not limited to the impact angle and jet properties, create a great deal of variability that affects the performance and penetration of the shaped charge. The large amount of impurities and voids in concrete, along with its heterogeneous nature and the general strength characteristics, make concrete a non-ideal material for shaped charge jet penetration. These material characteristics lead to a highly non-linear deformation behavior of the concrete target during a hyper-velocity impact.

Jan 1, 2011

By Tristan Worsey, Nathan Rouse, Evan Thibaud

Electronic detonators allow for variability and accuracy with blast delay selection and timing sequence. However, a single published guideline for selection of electronic timing delays is not available on the OneMine database. There are published documents that present options for timing with electronic detonators, some of which provide great detail and scientific evidence, but there is no single document that presents several different approaches with simple instructions on how to apply the various timing approaches. This paper reviews published electronic timing approaches and results, then presents guidelines for electronic timing for alternative mining methods, which include: bench blasting (ie. quarries) and crater blasting (ie. metals mines). Most of the approaches are based on calculating milliseconds per meter for rock types, as quantified by the rock sonic velocity. Guideline calculations are provided for recommended hole-to-hole delays and row-to-row delays for both free-faced bench blasting and crater blasting approaches. These are the two most common blasting methods for mining operations. Typically, free-faced bench blasting is the approach used in quarries with a bench height to burden ratio of around 4, and crater blasting is typically used in large blasthole diameter/short bench blasting in metals mines with a bench height to burden ratio of around 1. Mines may focus on fragmentation, mucking rates, ore movement distance and movement direction. Recommendations are also included to provide general recommendations based on a mine’s preference for movement and fragmentation. References include twelve studies on bench blasting and six studies on crater blasting. In addition, a discussion is included on the application of these recommendations at a full-scale surface gold mine.

Jan 21, 2025

By Alastair Torrance

The performance of commercial explosives is clearly influenced by the conditions under which they are used. Mining companies are supplied with Technical Data Sheets which provide details about explosive properties and its suitable application. These are generally produced using laboratory techniques which may not accurately reflect the quality and performance of the product in the field.

Jan 1, 2013

By D. Lynn Gordon, Larry B. Weston, Michael W. Manhart, Patrick R. Bowden, Michael W. Redmond

Study of confinement effects on detonation characteristics and subsequent fitting form development as a function of confiner strength and thickness.

Feb 1, 2020

By Rick Lamkie

When investigating citizen complaints about blast vibration and airblast, it is important to be able to establish the spatial relationships between blasts, blasting seismographs monitoring the events, and complainant structures to assess any directional impacts. The Pennsylvania Department of Environmental Protection (DEP) routinely uses hand-held GPS receivers to document these relationships. The waypoint (structures and seismograph monitoring locations) and tracking (blasting and permit areas) features are used to map a site. These data are imported into the software for editing and conversion to GPS Exchange (.gpx) format.

Jan 1, 2008

By Ambrose Buchanan, Rob Farnfield, Charles Adcock

Beginning on 7th September 1940 the City of London was subjected to 57 consecutive days of bombing in what became known as the ‘London Blitz’. To commemorate the 70th anniversary of this event a television series was commissioned that required the open detonation of World War 2 equivalent bombs close to purpose built structures constructed using period design and materials. The structures were built on a remote test facility in the North of England that is able to fire large quantities of explosive in the air.

Jan 1, 2011

By Ignacio Humeres Valdivia, Alejandro Ferrada Vergara

In the latest years, the use of innovative blasting techniques has become more frequent in mines all over the world. Such techniques allow the miner to be more aggressive in the distribution of explosive energy into the rock mass, e.g., stretching blasting patterns to improve fragmentation. Considering the different rock mass conditions and more energetic blasting designs, misfired shot events have occurred. After cause investigation, initiators have shown evidences of deformation by impact and/or loaded boreholes have resulted in emulsion desensitization, both presumably affected by dynamic pressure.

Jan 1, 2015

By Corry Goumans, Ron J. Elliot

This paper discusses the challenges encountered in drilling and blasting of a small diameter shaft underneath a parking garage in historic Gastown, Vancouver, BC. This project involved drilling in a restricted headroom area, blasting in a confined space environment, and excavating using a novel vacuum technique. The 1.2m x 1.2 m x 8.5m deep shaft was required for installation of a hydraulic piston for a show lift. The project called for very accurate drilling through inter-bedded sandstone and siltstone within the water table. Development of a unique blast design was required for blast vibration control on a historic structure located just 15.8 meters away. The shaft was successfully completed without damage to any of the surrounding structures.

Jan 1, 2004

By Philemon Desrochers, Ken Qian Liu

Following the success of the West Ore Zone distress mass blast in 2001 at Brunswick Mine, a similar approach was taken to distress the North Regional Pillar (NRP) which contained over 3 million tonnes of high grade ore. The NRP is located on the 1000 m Level with very poor hanging-wall (H/W) rock mass qualities. After an extensive geotechnical review, the distress slot is located close to the foot-wall (F/W) of the NRP in order to have the competent ore as H/W. The longitudinal area to distress covers 115 m along the strike and 85 m high from 1000 1-sub to 850 Sill. Prior to the final mass blast, 3 voids were created to allow rock swelling: the North void, the South void and the trench just below the mass blast. After over one year of preparation, the mass blast of 202,000 tonnes was successfully initiated on February 7, 2003 with 1561 electronic detonators and 210,000 kg of emulsion explosives. The blast achieved its objective of distressing the NRP as indicated the mine-wide micro-seismic monitoring system. This paper describes different stages of the project from void preparation to the mass blast itself, as well as some detailed aspects such as muck-pile prediction for mucking sequence with the help of DMC_Blast simulation code and electronic detonators.

Jan 1, 2004

By Mark S. Rayson, Jessy Lee, David O. Johnson, Matthew R. Rawls

The ability to manipulate the structure of liquid chemicals in an explosive is important in mining applications, where precision blasting is crucial for the safe, reliable, economical and eco-friendly extraction of ores. Static mixers allow explosives, emulsion-based in particular, to be custom-made as they offer precise and reproducible mixing without the need for moving mechanical parts. In this paper, we perform numerical simulations on the laminar mixing of two nitrate-based fluids in a Kenics static mixer unit for various mixer parameters. Two numerical methods were investigated in the study of the mixing pattern: solving the mass transfer equation and using particle tracking. The former introduces artificial numerical diffusion which can lead to spurious smearing of the component boundaries, a problem that can be avoided with the latter technique. We have also demonstrated that the particle tracing method is capable of qualitatively predicting the blending patterns under the conditions studied.

Jan 1, 2014

By Braden T. Lusk, Brett C. Jackson

The Kentucky Commissioner of the Department for Natural Resources, accompanied by a motion for accident prevention from Kentucky’s Explosive Industry and other associated fields, have requested for an Industry Flyrock Prevention Task Force to be formed by an Explosive Industry panel. This task force is led by Dr. Braden Lusk at the University of Kentucky. The mission of this task force is not only to identify the base causes of flyrock incidents based on analyzing historical data from events in the past, but also to track the advancement of flyrock elimination into the future.

Jan 1, 2014

By Brian Hawkins, David Bradley, Rachel Gooding, Lucas Rodriguez, Patrick Wilson, Kevin Wegman, Dhruv Mittal

To better protect the nation and inform difficult defense and preparedness decisions, the Department of Homeland Security (DHS) is performing a probabilistic risk assessment of explosive terrorism risk to the US homeland. After assessing existing models against requirements, well-developed mathematical descriptions and algorithms associated with explosives hazards were combined with probabilistic modeling techniques used in DHS chemical, biological, radiological, and nuclear (CBRN) terrorism risk assessments to create a suitable interior explosive consequence model for assessing the impact to human health.

Jan 1, 2018

By Joshua Hoffman, Braden Lusk, Kyle Perry

Despite its porous and lightweight characteristics, aluminum mesh is believed to have blast mitigation properties. The current use of the mesh includes fuel tanks for airplanes, boats, and fuel stations as well as light armored vehicles for the military. The mesh acts as an explosion suppressant by preventing fuel tanks from exploding when exposed to an ignition source. More recently, work has been performed to assess the ability of the mesh to mitigate blast pressures produced by high explosives.

Jan 1, 2009

By Rohan Stevens, Katsuhiro Kameyama, Osamu Iwata, Jinming Liao

In densely populated cities such as Hong Kong, where unoccupied space is becoming more valuable as the population grows, city planners are more often looking to underground space to meet the increasing need for transportation and services. Given the dense population of people, amenities and high-rise buildings above or near such underground space, it is essential to minimise any disturbance and potential damage during construction. Hence, the excavation of hard rock to develop such underground space can be highly restricted, expensive and time consuming. This is the case for many of the tunnels currently being excavated by drill and blast directly underneath Hong Kong’s busiest business districts and most popular residential areas.

Jan 1, 2013

By Luis Huaroc, Jorge Cardenas, José Salvador

One of the current challenges in mining is managing increasingly competent rock conditions within the mine-to-plant value chain, particularly when working with marginal ore grades. This study presents a case from a Peruvian open-pit operation where the mine plan projected a significant increase in rock hardness, as measured by the Axb index (parameters derived from the JK drop weight test). In response, the Drill and Blast Technical Team made efforts to increase the powder factor by reducing drill spacing and increasing the explosive charge, employing high-energy explosives (3,090 kJ/kg). However, this adjustment presented a challenge in achieving the fragmentation required to meet the target throughput of 97,500 tons/day, resulting in a shortfall of approximately 8.7% under the base case scenario. To overcome this technical challenge, the use of locally engineered ultra high-energy explosives was proposed, offering adjustable energy levels ranging from 3,210 to 3,570 kJ/kg. This solution enhanced ore blending strategies, calibrated to specific Axb ranges. The results also suggest that microfractures generated by the energetic blasting designs contributed significantly to downstream improvements. These outcomes demonstrate the value of a fully integrated mine-to-plant strategy, aligning blasting parameters with downstream processing performance to maximize operational efficiency. This solution led to a 10% increase in process plant efficiency, a 16% reduction in specific energy consumption during primary crushing, and a 13% reduction in the SAG mill. Additionally, shovel productivity rose by 18%, and the dig rate improved by up to 35%. Keywords: fragmentation, blending, high-energy explosive, power factor, microfractures, specific energy consumption and Axb model.

Jan 26, 2026

By Scott Scovira, Ruilin Yang

This paper presents a non-waveform blast vibration model for the near-fi eld. The model uses the concept of a dominant charge augmented by other contributing charges estimated using a scaled time window. The model accounts for the effect of broken ground created by earlier fi ring holes, amplitude attenuation, effects of signal broadening with travel distance from frequency attenuation, as well as asynchronous propagation of different wave types due to the wave velocity difference, the delay time effect, and non-linear superposition of near-fi eld vibration. The model uses an effective distance defi ned from the broken ground screening, and determines a dominant charge contributing to the PPV at a monitoring station. Then the model uses a time window for each individual charge to determine if it contributes to the PPV. The time window has a variable width to model the effects of the signal broadening with travel distance. For modeling the signal broadening, a generalized rock quality factor Qd is proposed. The time window includes a weighting function that diminishes the contribution for charges fi ring further from the dominant charge and this accounts for contribution arising from the timing difference between a contributing charge and the dominant charge. The model uses a non-linear charge weight superposition technique that scales the charge weights within the time window to the same distance of the dominant charge and superimposes the scaled charge weight. The case study demonstrates that the model provides useful predictions for near-fi eld blast vibrations.

Jan 1, 2008