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By Jan Westberg, Roger Holmberg, Bernt Larsson

Over the last couple of decades there has been an increased demand from the market for precision detonators, partly because of a need for better blasting results and partly because of a need for better vibration control. Today's detonators have a pyrotechnical delay element which gives a relatively high time scatter, increasing with the length of the delay time.

Jan 1, 1988

By David Cheung, S. Paul Singh

"The characteristics of a blasted muck pile can have a significant effect on the productivity and economyof loading and hauling operations. Poorly fragmented and tight muck piles, caused by insufficientdisplacement of the broken rock, lead to higher digging and hauling costs. Therefore muck pile must be tailored to suit the loading and hauling equipment. In order to achieve this objective, it is imperative to understand the relevant muck pile characteristics and factors governing them. In general, muck pile characteristics are governed by the blast design parameters, rock mass geology, explosive characteristics and post-blasting requirements."

Jan 1, 2017

By Emmett J. Ientilucci, Martin Held, Xuesong Liu

Mining is crucial for advancing technology and science by providing essential resources and materials. Quarry blasting, a necessary process in mining, releases these resources and chemicals, driving research and engineering improvements. However, NOx (nitrogen oxides) is an undesired contaminant produced during quarry blasts, posing a significant negative impact on mining activities. Therefore, detecting and quantifying NOx emissions is essential for designing effective blasts, analyzing their dynamics, and reducing contaminant production. Image processing and machine learning, including deep learning methods, have been applied to solve smoke plume detection and segmentation tasks. Most research has focused on smoke from campfires or forest fires, which are important for early fire and smoke detection. However, there is limited research on quarry blast smoke using machine learning methods, which presents challenges for recognizing the smoke plume from complex background scenarios and objects, including collapsed rocks, scattered soil dust and dirt, and the dynamic movement of the scene due to blast vibrations. Detecting NOx within the smoke plumes is further challenging because NOx must be distinguished from the overall smoke plume, as they share many common spatial features. To resolve this issue, we propose an ensemble method for NOx detection that combines smoke plume segmentation with NOx fume detection. First, we apply a smoke plume segmentation model to identify the smoke plume regions. Then, we use these masked-out smoke plume regions to detect NOx based on its unique color features. The first stage of the ensemble method helps block out complicated confusers in the background, such as reddish and brownish dirt. Next, we specifically design a color classifier for NOx to further improve its sensitivity. We evaluate the overall video-wise performance using accuracy, false alarm, and miss rates based on sampled image frames from videos. Additionally, we assess the mean Intersection over Union (mIoU) for smoke plume segmentation and the mean Average Precision (mAP) for image-wise performance from an algorithmic perspective. In summary, this paper represents the first attempt to apply machine learning approaches to NOx detection in a memory-efficient and time-efficient manner.

Jan 21, 2025

By Zong-Xian Zhang

In sublevel caving mines, serious eyebrow break usually gives rise to lower ore recovery, higher dilution, and worse safety for the people working in the field. For example, chargers must go near the caving region and stand under the damaged eyebrow where a hanging stone may suddenly fall down or rock fragments may quickly roll down.

Jan 1, 2011

By Muhammad Yamani, Marsell Riviera, Herry Saputra, Rizky Amin

Drill and Blast processes in hot and reactive ground conditions are a severe challenge in mining, especially in the blasting process. Our main objective is safety issues without compromising the blasting outcome. Safety concerns include unexpected detonation, product damage, and misfire. However, apart from the issue of blasting safety, it is also crucial to maintain good results such as fragmentation, loader productivity, and ore dilution control. Therefore, we use a different product selection method to produce a safe and efficient blast. Pit Araren is one of the pits of the Tokatindung Gold Mine Project in North Sulawesi Province, Indonesia, classified as hot and reactive ground conditions that range from elevation of 25mRL temperature could reach to 98⁰C (208,4⁰F) based on actual measurement. The previous practice for blast holes with temperatures above 70⁰C (158⁰F) loaded with the primer that was specifically designed for hot and reactive ground conditions consisting of detonating cord and packages emulsion that specifically formulated to inhibit exothermic reaction then tied in with a combination of non-electric surface delay detonator and detonating cord initiator (short length non-electric surface delay detonator housed in plastic connector).

Feb 6, 2023

By E. Contestabile, B. von Rosen

Recently, the Canadian Explosives Research Laboratory (CERL) completed its investigation of a truck accident, which involved 18,000 kg of commercial explosives, 13,000 kg of which was ANFO. Over the three years of the investigation unconfined burns of piles of ANFO were performed. In its final phase of the investigation, two burn trials were performed in an attempt to recreate the accident and the ensuing fire, to identify probable mechanisms that led from burning to detonation. Two full-scale tests were performed using complete tractor-trailers. In each test, the trucks were placed in a jack-knifed position with the majority of the explosives located on the ground in front of the trailer. The explosives were placed in a manner to provide maximum confinement and to maximize the possibility of explosion/detonation while remaining as faithful as possible to the perceived accident geometry. The tests were instrumented using thermocouples and video cameras and observations were made on the burning characteristics of the explosives, tractor-trailer and tractor-trailer components. In each test the explosives burned calmly for approximately 80 minutes. There was no evidence of explosion or of unstable burning. The heat caused several truck components to rupture violently. These included the tires, some engine components, the spring brake chambers and possibly the fuel tanks. Of these, the most violent were the truck tires. Although no quantitative data was gathered on rupture violence or fragment velocity, it is speculated that several truck components might produce fragments with sufficient energy to initiate heat-sensitised explosives under favourable circumstances.

Jan 1, 2004

"In this work a blasting seismograph was tested on a vibration shaker controlled by a single-point laser Doppler vibrometer (LDV). A total of 43 tests were made to measure the transfer properties(transmissibility and phase shift) of the basic elements of the full monitoring chain and investigate theperformance of the full system. The main elements of the seismograph are described by second ordertransfer functions with typical parameters calibrated through nonlinear fit of the measured responses. The resulting transfer function is used to compare the behavior of the tested seismograph with fourtheoretical seismographs representative of those used in blasting. Fifteen theoretical inputs are runthrough the transfer function of each seismograph to assess their steady-response. The error (expressed as gain) in the peak velocity has been assessed. It varies from -1.5 to 2.3 dB (equivalent to atransmissibility of 0.84 to 1.3, respectively) depending on the seismograph and frequencies of the input.The largest errors occurred for input signals with frequencies in the low (<32 Hz) or high ranges (>125Hz), where the mechanical, electronics and digital parts of the seismograph modify the signals. Seismographs with the nominal transfer function described by DIN 45669:1:2010 are ranked with the smallest errors. Monitoring devices with transmissibility around one in a narrow bandwidth, in line with ISEE suggested criteria for amplitude response, involve large phase shifts at low and high frequencies, resulting in a worst performance."

Jan 1, 2017

By Tapan Goswami

The main objective of the blasting phase in a coal mining operation is to maximise the coal recovery. However, coal loss due to blasting is a serious problem. The Australian Coal Association Research Programme (ACARP) reported in 2011 that in Australia one in every ten coal mines is completely wasted due to such losses. Coal is either lost in the spoil, largely due to the blasting operation or becomes diluted and cannot be recovered entirely. The major coal loss mechanisms include losses from the coal seam roof, the floor, the front edge and from dilution. Coal damage and loss mechanisms during cast blasting that have been observed by various authors include: •Excessive cast dragging the coal edge in the cast direction. Movements of this nature are oftenassociated with the formation of trenches. •Spatial movement of overburden where rock shears and moves in a plane above the coal seam,which damages and dilutes the coal. •Rock falling over the coal during the blast often producing indentations in the exposed coal. •The inappropriate use of bulk and initiating explosives that often results in coal damage. •Insufficient stand-off distances from the coal. The Australian coal mining industry has gone a long way towards addressing the coal loss issues since 2011: almost all operations now deploy touch-coal drilling and sporadically use gamma logging for loading overburden. A study was conducted to compare the effectiveness of touch-coal information in which some touch-coal blastholes were drilled on a fixed or random pattern. In another study, some blastholes were drilled to the touch-coal, gamma-logged and mapped to determine stand-off distances. It was found that the coal roof surface created by gamma-logged holes was the most effective option for minimising coal loss. As a result, a variable stand-off distance was found to be the key to minimising losses. This paper discusses the importance of coal mapping, the rock properties of the roof and floor interface of the coal seam, and the significance of loading and initiating designs in minimising coal damage. Furthermore, the importance of using electronic initiators cannot be emphasised enough. This paper also discusses how a cast blast can be initiated from many locations by mitigating geological abnormalities and thereby avoiding spatial movement of rock shearing in a plane above the coal seam.

By Peter Dare-Bryan, Will Hunt, Lee Julian

It is well-known that blasting has an economic effect on grade control activities. However, until recently, methods did not exist for measuring the grade control value change caused by the blast. Rules of thumb were the best method to minimize ore loss and dilution, as simulation has been traditionally constrained by time and computer power. Even with these rules followed, an extensive study performed on over 150 blasts showed that the value change caused by the blasts followed a normal distribution – some blasts created value, and some blasts destroyed value. The question naturally asked was “How can we ensure the blast designs are optimized to create value?” Recent advancements in computer power have enabled real-time blasting simulations that create post-blast grade control models before the blast is fired. Understanding what will happen before it happens allows blasters and grade control personnel to iterate designs, searching for the highest value achievable.

Feb 6, 2023

By Tapan Goswami

This paper discusses the importance of coal mapping, the rock properties of the roof and floor interface of the coal seam, and the significance of loading and initiating designs in minimising coal damage. Furthermore, the importance of using electronic initiators cannot be emphasised enough. This paper also discusses how a cast blast can be initiated from many locations by mitigating geological abnormalities and thereby avoiding spatial movement of rock shearing in a plane above the coal seam.

Feb 1, 2020

By Mark A. Rugen

It may be difficult to imagine but small engineering companies do exist, even in relatively large cities like San Antonio. Due to the limited capital available for the purchase or use of equipment such as computers, many times the small company must evaluate a blast damage claim by limited means. This paper will discuss how a relatively small company has managed to become the leading blast damage experts in an area without the use of computers or sophisticated equipment. It will be shown that a single individual in a company who is familiar with vibration theory, local soil conditions and who does not mind spending long hours with a calculator and reference books can satisfy both the insuranc e adjuster or attorney, and the homeowner concerning the claim. Several examples will be given which show the typical flow of work and the ultimate outcome. This paper will focus on the special problems encountered by a small firm and how these can be overcome, and the unique interaction of a small engineering firm with both the insurance adjuster/attorney and the homowner that can lead to an equitable settlement of the claim.

Jan 1, 1983

By Franklin J. A, Tam C. Palangio, N H. Maerz

WipFrag systems I, II and III have become the world standard in photoanalysis systems to measure particle sizes. Mines, quarries and excavating contractors can now easily measure blast results and track the progress of optimization efforts. This technology was developed and evolved ~to allow automatic measurements of the size distribution of particles on moving conveyors, in truck boxesand on crusher feeds. Production machinery can now be controlled by photoanalysis results and multiple cameras allow various locations to be monitored by a single system. Blast designs can, be monitored on a shot by shot basis. Changes in delay times, explosives, patterns and hole sizes can be quickly evaluated. Along with this measurement capability has come a heightened awareness of the importance of “optimum size” and uniformity of particles for lowest cost production and material handling efficiency. In the past, savings in the “drill / blast” cycle of the operation were sometimes overshadowed by downstream production costs related to fragmentation. Now total production costs can be compared with fragmentation sizes, which will immediately show the trend towards optimum size for economical production. No cost reduction program can be complete without this critical information.

Jan 1, 1998

By Paul Worsey, Randall Franklin

This paper is based on an undergraduate research project undertaken for the explosives emphasis in the UMR mining engineering degree program by the first author. The purpose of the selected research topic was to investigate the impact sensitivity of commercial detonators to determine their relative safety for handling and how much abuse they can take without accidentally firing. A modified BAM tester was used for the investigation. Both electric and non electric detonators were impacted at incremental positions along their length to determine the relative effect of their various components. Repeat impact tests were also conducted to see how a damaged cap would react to repeated abuse. The results indicate that it takes a significant amount of impact energy to initiate commercial detonators. They also indicate that repeated abuse can increase sensitivity. Modern commercial detonators appear to be relatively insensitive to impact (an order of magnitude above RDX in the standard BAM test) and this is mainly due to their construction. This explains why damaged caps with exposed powder are more sensitive. Their measured insensitivity correlates with rough handling not being a major cause of blasting accidents.

Jan 1, 2004

By Park McLure, Paul Kunze

Abandoned underground mine workings have been regularly encountered in open pit mining excavations for many years, for the most part without many serious problems resulting. During the last several years however, some tragic occurrences and near misses have resulted when these old workings were intercepted. This paper will report on the problem as it relates to western open pit mining and will describe several techniques that can be used to identify problem areas before they are reached: Utilization of old maps and engineering data, long hole drilling and probing, and the use of subsurface investigation in the form of ground penetrating radar are the detection methods that will be discussed. The paper will describe some possible actions, once potential problem areas are identified. Drilling and blasting crews are usually exposed to the hazards involved when these situations arise because of their "on the ground" working environment. It is therefore appropriate that some of the best methods of dealing with these hazards once they are identified, seems to involve innovative and creative blast designs. The paper will discuss these approaches and describe an example of this aspect of the solution.

Jan 1, 1993

By Thomas M. Keevin, Gregory L. Hempen

A study was conducted to measure underwater pressures associated with confined borehole shooting used to remove rock for The Kill Van Kull Deepening Project, U.S. Army Corps of Engineers, New York District. A major natural-resource-agency concern was the potential for fish mortality during explosive rock removal. Currently, fish mortality models are based on testing programs that exposed captured organisms to open-water blasts. Natural resource agencies, without in-house explosive engineering expertise, generally are not familiar with the physical properties of blasting underwater. Confined shots are most often used for demolition and rock removal underwater. Pressure amplitudes from confined blasts are significantly reduced as compared to open-water blasts that, are commonly used for fish testing The duties of natural resource agencies are made even more difficult by the lack of published data on pressures associated with confined blasting. As a result, explosive weights for confined shots mistakenly have been used to run mortality models that were developed using open-water blast pressure data. This study was conducted to collect pressure measurements during rock removal for the KVK deepening project and compare those data with computed peak pressures for open-water explosions.

Jan 1, 2005

By W. J. Birch, R. Farnfield

Nuisance caused by perceived high vibration levels as a result of blasting on quarries and opencast coal mine is now the number one environmental concern of residents living adjacent to such operations. The intrinsic nature of blast vibration monitoring and prediction is that it is impossible to accurately forecast the vibration levels that will be experienced by a given blast at a given location. Thus it is that a statistical approach to the problem is the only viable option. Unfortunately, persuading local residents living adjacent to a project that requires blasting that this is the best way of safe guarding both their homes and their quality of life is not an easy task. Thus routine monitoring involving both operators and regulators play a key role in building trust. However, public confidence is often shaken when regulators and operators use two different blast monitoring instruments side by side to record a blast at a local resident’s house and arrive at different results. To make certain that this does not happen in future, what is needed is a protocol that ensures that any two different blasting seismographs give the same peak particle velocity values at the same observation point. To do this all the equipment manufacturers, regulators and relevant professional explosive engineering bodies need to be involved.

Jan 1, 2014

By Matt Brandon

This case study demonstrates how integrating drone and GPS surveying with 3D modeling software creates more effective blast designs that address specific geotechnical challenges while improving safety and blast performance. In this case study an 80ft (25m) highwall experienced recurring slip plane failures exacerbated by a previously mined 40ft (12m) bench that removed back support, creating an unstable triangular rock mass. Previous blasting along this wall displaced the upper 40ft (12m) of material, opening geological discontinuities and causing progressive slope failures that compromised crew safety and blast effectiveness. High-resolution drone photogrammetry, GPS surveying, and laser measurements were employed to precisely map slip planes, bedding planes, and fault structures within the bench geometry. These geological features were imported into 3D design software to develop a shot pattern that strategically utilizes natural rock discontinuities rather than working against them. GPS-guided hole placement ensured accurate field implementation, while marking geological features on the surface of the bench provided visual references for the blast crew. The final blast design positioned the last row of holes to break preferentially along an existing slip plane while avoiding intersecting the next slip plane behind the blast. Explosive loading and timing sequences were adjusted based on the hole location relative to the 3D geological model to optimize fragmentation while maintaining wall stability. The optimized design improved highwall stability significantly, by reducing the slip plane failure mechanism that had previously compromised operations. Measurable improvements included enhanced highwall stability, reduced back-break, improved blast performance, and reduced safety risks for equipment operators and blast crews. Two subsequent shots using identical methodology were able to remove the rest of this problem area, confirming the repeatability and effectiveness of this integrated approach. This methodology demonstrates practical integration of surveying technologies with geological understanding to solve complex blasting challenges. Accurate 3D modeling of geological features enables blast designers to work with natural rock structures rather than against them, resulting in safer, more effective blasting practices. This case study shows the value of understanding the precise locations of geological features for optimizing blast design and provides a replicable process for addressing geotechnical challenges in blasting operations.

Jan 26, 2026

By Kwang-Tae Kim, Yong-Kun Choi, Jeong-Soo Chong, Yun-Jae Lee

An annex building at the former Agency for National Security Planning(NSP) complex located in downtown Seoul was demolished by progressive collapse method. This work was done as a part of efforts to restore the landscape of Namsan Mountain which lies in the Center of Seoul. The five-story reinforced concrete structure was razed in 5.5 seconds by the 29kg of high powered explosives which were placed in some 320 holes in the building with floor area of 2,577 m². The asbetos and all the other finishing materials in the building were removed before the demolition and the specially coated wrap minimized the spread of blasting dust. Seismic and air overpressure waves were monitored at 8 points, which were below safety limits and the continuous communication with neighborhood prevented any complaint.

Jan 1, 1998

By Harry L. Siebert

A major Arizona highway project is jeopardizing site safety and security because of the lane rental policy. One million cubic yards of rock must be fragmented to provide two additional lanes parallel to the existing roadway. Traffic is stopped during blasting operations.

Jan 1, 1997

By Wang Xuguang, Tian Ruigi, Xiong Shangbin, Xiong Daiyu

Combining action features of explosive shock with those of natural lignocellulosic biomass structure, we have successfully developed a new explosive shock dilatation and separation technique for pretreatment of natural lignocellulosic materials in the laboratory. Based on a brief introduction to the technical background and experimental procedure of this new method, some preliminary experimental results are given and discussed: the scanning electron microscope (SEM) qualitative observation results show that for treated natural lignocellulosic sample such as corn cob etc., their length of fibre bundle shortens, fibre bundle arrange disorders, biomass appearance and structure of samples largely change to be dilatation and loose state. The dilute acid hydrolysis quantitative measure results show that for treated samples, the overall yield of the reducing sugar largely increases, hydrolysis rate of corn cob sample is over 80%, rate and speed of hydrolysis are increased by times.

Jan 1, 1998