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By Garfiansyah Rayes

In 2023, an Indonesian coal mine experienced significant contamination of an emulsion blend explosive by dynamic mud and water flow, triggered by flooding due to exceptionally high rainfall. This intrusion into explosive columns compromised the stability and efficiency of blasting operations, thereby impacting overall mining productivity. The extent and impact of these contaminants on the stability and performance of the emulsion blend explosive were rigorously analyzed through a robust assessment methodology that included comprehensive field measurements and controlled laboratory experiments designed to replicate the challenging site conditions. Utilizing a combination of theoretical calculations and Computational Fluid Dynamics (CFD) simulations, this study evaluates the kinetic interactions between dynamic mud flows and emulsion explosives within drill holes. The methodology integrates Torricelli’s theorem for velocity assessments and Darcy’s Law for understanding the penetration mechanics of mud into the emulsion blend. CFD simulations are further correlated with actual blast data to assess discrepancies between theoretical predictions and real-world outcomes. Results demonstrate a significant reduction in the velocity of detonation (VOD) of the explo-sives, traced directly to mud contamination levels, which align with the quantified penetration rates in the study. Practical measures for mitigating such contamination are proposed, including the reinforcement of water-ways, culverts, and bund walls at drilling locations based on validated simulation data. Additionally, rec-ommendations for operational adjustments during high rainfall events are discussed, aiming to enhance blasting safety and efficiency. The paper concludes by suggesting future research directions towards the development of more resilient emulsion formulations and enhanced predictive modeling techniques to better forecast the impacts of en-vironmental variables on explosive performance in mining operations

Jan 21, 2025

By Juan Carlos Vasquez, Romel Villanueva

We present the results of our field research on the variation of the density of the gassed explosives and their influence on the blasting results in the Peruvian mines: Yanacocha, Toquepala and Antamina. Currently, 90% of Peruvian mines uses gassed explosives, for their economic and technical benefits. But new practices and design criteria have had to be adopted, and the most important a careful control of the in-hole density, whose variation in the depth of the hole strongly affects the detonation process.

Feb 1, 2020

By Lloyd Litwin

The ARTA 2008 Project (Alpha Ridge Test of Appurtenance) was a Canadian Government sponsored deep water seismic survey carried out on the high arctic permanent polar ice cap. This Geological Survey of Canada operation was the second seismic research project in the high Arctic and was monitored by the Danish Government. Utilizing 100% air support from Eureka and then helicopters from an ice based tent camp north of Ellesmere Island, the five week study was accomplished in the early spring just after the sun returned to the far north.

Jan 1, 2011

By Chris Breeds, Larry Leone, Jerry Wallace

One of the Authors was recently retained to provide a professional engineering analysis of the potential impacts from underwater blasts used to enlarge intake tunnels at the Cheesman Dam near Denver in Colorado and to design Blast Protection Bags that could be installed in each tunnel to protect the 100- year old downstream valve structures.

Jan 1, 2012

By Ricardo Chavex, Adrien Letellier

Flyrock remains one of the most critical issues in open-pit blasting. Despite the significant improvements made with modern surveying methods, the necessity remains to define sensible danger zones around blasting areas. Therefore, many semi-empirical models predict flyrock distances based on trajectory calculations and probabilistic adjustments. However, most are merely based on nominal parameters, even though a considerable amount of precise data is nowadays available thanks to modern measurement techniques using lasers, GPS, drones, and probes. These data provide accurate information about the actual field circumstances of a blast concerning geometry and rock-mass conditions. So how can we use and integrate them into existing flyrock models? The answer to this question can significantly improve the accuracy of flyrock prediction models and enhance safety. This paper will present a method to adapt existing models to actual field data using appropriate software and digital tools during the blast design process. In addition to calculating a more pertinent danger zone perimeter, this method provides an efficient and practical tool that helps prevent flyrock incidents. Indeed, it allows the blast designer and shot firer to be warned if there is a hazardous critical deviation due to local conditions. Moreover, it also enables blasters to communicate better and share the visualization of the blast-specific evacuation zone. The paper will also discuss how this method can be calibrated and how it has been used to analyze some actual flyrock incidents.

Jan 21, 2025

By P A. Lang

Canada is constructing an Underground Research Laboratory as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in stable rock formations. Careful blasting methods have been designed and quality control procedures have been used for the excavation of the access headings in the underground facilities. This paper describes the work done between 1984 December and 1986 December at the second level, 240 metres below surface.

Jan 1, 1987

By Hans-Peter Rossmanith

Fracture mechanics (Atkinson 1987, Broek 1988, Rossmanith 1978-2002, 1983, 1997, Kanninen & Popelar 1985) and wave propagation (Graf 1975, Rinehart 1975) form the main ingredients in the new electronic detonator based blasting technology. The full potential of using short delay initiation timing in bench and underground blasting can only be exploited if the underlying physical processes are properly understood. From a structural geology point of view, in many open pit mine operations, blasting is performed in incompetent and/or loose rock. Under such conditions the stress waves produced by blasting very quickly dissipate in the rock mass and often their energy cannot effectively be put to work. This contribution shows the effect of open and closed joints – and to some degree also faulting – on the blast wave field and shows the influence of structural geology on the blasting result. A simple engineering method which combines wave propagation and impact mechanics is developed in order to assist the non-scientifically trained blaster in understanding blasting in blocky rock formations. Extensive use will be made of the so-called Lagrange diagram which was introduced in detail in the author’s previous lecture at ISEE 2003 (Rossmanith 2003). This presentation can be considered a continuation of the 2003 presentation.

Jan 1, 2004

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 Tapan Goswami, Stephen Jeric, Geoff Brent

Highwall failures in large deep open cut mines have very significant safety and commercial implications. There are many factors influencing the stability of highwalls. The major influence is the interaction of the local geology with the shape of the pit wall. This factor is in the realm of the geotechnical engineer and is beyond the control of the blasting engineer. However, a secondary influence is the blastinduced damage to the wall. In most open cut metal mines the blasting strategy to control this damage involves the use of separate production and trim blasts bounded by presplits at the final wall.

Jan 1, 2011

By Richard Givens, Thomas Baginski

Technological advancements in warhead designs and implementations have driven the development of arrayed initiation networks of highly accurate, highly reliable, and extremely safe detonators. Recent development efforts have produced advanced Exploding Foil Initiator (EFI) based systems that have been adapted for civilian use in commercial blasting applications.1,2,3,4,5 This novel, high technology system promises multiple improvements and advantages over the manufacturing, transportation, tracking, storage, inventory and field operation of current detonator systems. Ultimately the insertion of this technology would result in fielding a Non-Energetics Based Detonator (NEBD). Insertion of complementary technologies into the detonator’s supporting systems would greatly advance current detonator hardware/software.

Jan 1, 2011

By Türker Hüdaverdi, Özge Akyildiz

"Efficiency of blast operations depends on fragmentation, overbreak, muckpile profile anddisplacement, vibration, airblast, flyrock and damage to wall or slope stability. To provide all these conditions at the optimal level, determination of rock mass properties (in-situ block size, joint spacing and orientation) is the very first step during design stage of rock blasting. Image analysis software is used not only to determine the fragmentation level of muckpile but also to characterize the bench face. In this study, an image analysis software was used to determine apparent block size of bench face and to measure blast fragmentation of muckpile. The source of errors and the vital points to be taken into consideration were explained for bench face characterization andfragmentation measurement. Since it provides much better results than previous techniques and it is not intrusive to production process, image analysis technique is considered as one of the most efficient and preferred way for fragmentation analysis. Besides these advantages, there are some weak points of image analysis software. Lighting is one of the most important factors for photographs captured for in-situ block size analysis and fragmentation analysis. Lighting determines shadow formation. In an ideal image, particles are clearly delineated by soft shadows. If shadows are too strong (dark), analysis suffers. Appropriate scale should be replaced onto blast muckpile during site measurements. The location of the scale in image affects the results of analysis. Also, the densityand orientation of discontinuities should be considered during application of image analysis technique to characterize bench faces. In this study, image analysis software was applied in thesandstone, limestone quarries of Istanbul region and an open pit boron mine. All image analysis, evaluations and results were made based on the site measurements."

Jan 1, 2017

By G. A. Walsh, M. Timm, S. M. Geerts

This paper will discuss the effectiveness and the general use of improvised shaped charges. Testing was conducted by the New Mexico Tech Student Chapter of ISEE and held at EMRTC. The first series of tests conducted was to illustrate the performance of different features of the shaped charge. A PVC pipe filled with C4 with no cavity, PVC with an unlined conical cavity, PVC with a copper lined conical cavity and no standoff, and lastly a PVC pipe with a copper lined cavity and a 1.5 cone diameter standoff.

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 Leslie C. Taylor, Anthony L. Kee

Computational modeling of explosively loaded saturated sand on a suspended plate is an inherently complex problem. In this study a computational method is used to predict the dynamic pressure load/impulse from a buried charge. A fully coupled code modeling the explosive charge, sand and air with a Eulerian mesh and the plate structure with Lagrange elements, such as Gemini-Dyna, is an appropriate computational tool. In water-saturated sand, the loadings are soil and water-transmitted shock and bubble or blast effects depending on the depth and the charge size. The computations provide the capability to determine the total impulse load placed on a horizontal plate on or above the soil due to an explosion in the saturated sand for different burial depths in saturated sand and different plate stand off distances. The following test case will be presented: (a) 4.5 Kg (10 lbs) TNT, 10.16 cm (4 in) depth of burial to top of charge, and 20.32 cm (8 inch) stand off distance (Test 4).

Jan 1, 2005

By Alastair Torrance, Gary Cavanough

Over the past two years a research project has been performed on reactive and hot ground. A key finding is that host materials including carbonates and coal are inhibitors to the reaction of sulphide and nitrates. The mechanism of this inhibition is pH buffering and isolating the surface of sulphide from reactants. It has been identified that acidity is a key driver of the reaction with a pH of 2 required for a reactivity event. A series of decomposition experiments confirmed that reactive and hot ground are essentially the same phenomenon with the heating produced either by the reaction of sulphide with nitrates or an external heat source. The results indicate that the key driver of detonation in reactive ground is energy and heat released from the acid induced reaction of sulphide and nitrate with no indications of sulphide being a catalyst or contributor to detonation apart from being a heat source. There must be sufficient sulphide and thermal insulation to provide and retain enough heat for detonation to occur. A pathway to detonation is postulated whereby the heat travels upwards and results in evaporation of water in the explosive. When the temperature reaches approximately 200°C (400°F) the ammonium nitrate starts to decompose, decreasing the mass of the reacting species. The material in the top layers has reduced density and specific heat hence the temperature of the top region rapidly increases up to >1000°C (1800°F) and may initiate detonation. Field tests on loaded blast holes support this proposed mechanism. Case studies are presented whereby the research findings are used to provide an analysis of historical reactive ground events.

Jan 21, 2025

By Jonathan Heiner

Rio Tinto Bingham Canyon Mine started its South Wall Push Back (SPB) in 2011. This push back will mine through the only road to the pit bottom (the 10%). The pit bottom is the main ore sector for the mine and supplies about 80 to 90% of the ore. In late 2017 the mine set off a blast in SPB that created a small wedge failure on the high wall between SPB and the 10%. This wedge failure released a rock approximately 20 minutes after that blast that rolled down the wall landing on the 10% near and then contacting a light vehicle

Jan 1, 2019

By Saeed Karimifard, Saman Nouranian, Shahram Tafazoli, Bahram Sameti, Frank Chu, Caitlin McKinnon, Tetiana Konstantynivska, Glen Turner

We propose a particle size analysis solution for haul trucks that does not impact current operational workflows. Using artificial intelligence (AI) and 3D imaging technology, our solution reliably localizes and identifies haul trucks as they drive by, then accurately calculates the particle size distribution of the visible material in each truck load. In this paper, we identify the challenges of designing and implementing the proposed solution and explain the strategies we employ to overcome these. We also discuss a method for boulder detection that leverages the existing deep learning architecture to significantly reduce crusher downtime caused by oversized rocks

Feb 1, 2020

By John C. Adams, Darrel D. Porter

After conventional drill and shoot methods were determined to be unfeasible due the fractured nature of the ground, a "coyote" blast was designed to produce 250,000 tons of rock from Rhone-Poulenc's Maiden Rock silica pit located near Butte, MT. This paper will cover the design and excavation of the explosive drifts, the placement and priming of 190,000 pounds of explosives, and the backfilling of the drift to provide confinement of the charges.

Jan 1, 1993

By Neal Lee

Reduced relief horizontally means an increase in energy expended vertically into the rock surrounding the stemming column, and potentially through the stemming column. The vast majority of holes in any surface blasting operation are afforded two horizontal relief faces at the moment of firing, whether by existing relief faces in front of and to one side, or previously blasted hole(s) in front of and to one side of the holes in question. When the energy expended in any hole on the blast pattern has less than two Horizontal Relief Planes or faces (referred to moving forward here as “HRPs”) available to it at the moment of firing, a higher percentage of the available energy is directed vertically. In the analysis of recorded videos by the author, one will note the fact that stemming ejection/flyrock is observed to a much greater degree from the center of almost all patterns when they are timed to “pull out of the middle” (“box cut" timed patterns). This is because the first hole to fire in each row has only one Horizontal Relief Plane, which significantly decreases horizontal avenue for energy release for these holes. This of course results in an increase in the amount of energy expended vertically. This paper proposes a novel methodology to modify the stemming to better use the explosives energy of each hole, while controlling side effects such as flyrock and airblast.

Feb 6, 2023

By Tom BoBo, Seth Gering, Jeff Loeb

Presenting a D&B feedback loop built on a well-designed blast, proven fragmentation analysis and blast monitoring solutions, underpinned by technology that not only increases profit from every blast, but also increases a mine’s purchasing power over one of the most expensive part of the process – explosives.

Feb 1, 2020