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By Walter Valery, Sarma Kanchibotla

Due to the global financial crisis, the world economy has turned upside down and most major economies in the world are facing severe recession for the past one and half year. During this period most commodity prices have tumbled by more than half from their peaks and such a sudden and severe economic downturn is not seen since the great depression. This sudden drop in commodity prices and lack of credit made many mining operations unviable and even those mines that are marginally viable at this point are operating under severe cost pressures and capital expenditure restrictions.

Jan 1, 2010

By Tristan Worsey, Nathan Rouse, Daykin Schnell

The authors were retained by a proposed underground metals mine operation to evaluate the potential blast vibration amplitudes that could be generated at surface structures above the proposed mine. Literature reviews of published blasting documentation gave little information, data, or models on surface blast vibrations produced by underground mines. At the client’s request, the authors contacted a number of underground mining operations to evaluate interest in sharing blast vibration data with the authors so that the authors could develop an underground-to-surface blast vibration regression equation.

Feb 1, 2020

By Cesar Guerra, Alejandro Rojas, Dr. Jhon Silva, Luis Velasquez

The ANN method is applied to predict the P_80 size in one open pit gold mine in Peru. The ANN was implemented in Matlab programming language, and the results from the ANN are compared with data obtained using photo-fragmentation analysis software.

Feb 1, 2020

By Thomas Pallua, William C. Gates

"Two major railroad companies have identified several segments along the railroad corridor betweenTehachapi and Bakersfield, Kern County in California that require construction of a second track to improve operations in this area. The total project proposes an upgrade of five segments along the Tehachapi-Bakersfield route. The authors focused on two segments: Walong to Marcel and Cliff Siding Extension. The second track project comprised design of a through-cut adjacent to an existing tunnel and up to 120-feet-high (36m) side-hill cuts (both in granitic rock). The authors characterized the geologic ground conditions and ground behavior, including rock mass quality and strength using a combination of rock core drilling and rock slope mapping. The rock mass is generally characterized as granitic tonalite with strong core stones surrounded by a matrix of decomposed granite (DG)."

Jan 1, 2017

By Mick Fritz, Ryan Gilmore

The Center for Disease Control [CDC] is in the midst of a twenty year project, part of which includes demolishing existing buildings and erecting taller, more modern structures within the same foundation foot print. Controlled Blasting Inc, a large and experienced construction drilling and blasting company in Metro Atlanta, was contracted to provide the drilling and blasting for the new building foundations. Working on a construction site, in this type of environment, creates many challenges for the drilling and blasting crews.

Jan 1, 2008

By Thomas E. Ricketts

Occidental Oil Shale, Inc. constructed two commercial-sized modified in situ (MIS) retorts, Retorts 7 and 8, at its Logan Wash Oil Shale Mine in February and April 1981, respectively. One of the primary objectives of this two-retort program was to examine large-scale blasting reproducibility for commercial-sized retorts. The blast design used 545 blastholes and 550,000 pounds of explosive in ANFO equivalent per retort. Each retort was blasted using millisecond delay blasting caps tied into a single round. The blasts resulted in rubble beds very close to one another and to predicted results obtained using newly developed limited void blasting technology. The heights of the remaining void rooms over the beds after blasting were within 0.3 feet of one another. This excellent reproducibility is brought into true perspective when compared to the scale of the rubble beds which were 230 feet high with volumes of over six million cubic feet each.

Jan 1, 1984

By Andrew Palangio, Blessing Taiwo

Understanding rock mass structural features is essential for optimizing blast design, highwall control, and evaluating post-blast performance in both surface and underground mining operations. This paper presents a comprehensive methodology utilizing image-based structural mapping to accurately characterize geological discontinuities including joints, faults, and lineations captured from both terrestrial and aerial imagery at varying scales. Key structural parameters such as joint orientation, spacing, and apparent in-situ block size are extracted to understand rock mass classification and enhance blast design inputs with greater geotechnical precision. The study introduces a significant enhancement to the existing discontinuity assessment algorithm by integrating a deep learning-assisted detection process. This improvement enables more accurate, quantitative and consistent identification of pre-existing cracks and surface features across complex bench free faces. The enhanced system facilitates better evaluation of how structural features influence blast fragmentation, energy distribution, and slope stability. A case study from a limestone quarry illustrates the use of a derived comminution factor based on the relationship between joint-controlled pre-blast block sizes and post-blast fragmentation to evaluate blast performance and optimize future design strategies. The results highlight the value of structural analysis in reducing overbreak, minimizing underbreak, and improving fragmentation predictability. This paper emphasizes the importance of integrating structural assessments into the blasting workflow to enable a more data-driven, geotechnically informed, and performance-optimized approach to modern blast design and evaluation.

Jan 26, 2026

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 Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By Clara Godoy, Álvaro Dapía, Paulo Couceiro, Pablo Segarra, José Ángel Sanchidrián, Juan Navarro

This paper applies geostatistical tools in Measure While Drilling (MWD) data to estimate the probability distribution of values in all the points of the studied domain in order to assess the continuity of rock classes between boreholes. The analyses carried out by Ghosh et al. (2018) and Navarro et al. (2019) have been used as starting point of this work to classify the geotechnical rock condition in four classes: solid rock, fractured rock, cave- in rock and cavity. From it, an application for the geotechnical rock condition of orebodies have been developed, aiming at characterizing the rock before the charging the holes to minimize unexpected rock conditions and to address issues associated with charging and blasting operations. Such problems are closely related with non-optimal rock fragmentation after blasting.

Feb 1, 2020

By E. Vilaescusa, J. Eloranta

The work presented in this paper investigates the influence of non-ideal detonation characteristics related to the blasthole diameter, base emulsion sensitivity (micro-balloon sensitised versus unsensitised) and percent emulsion on the explosive shock energy available to break rock using ANFOemulsion blends. A series of theoretical equal powder factor bench blasting patterns with hole diameters of 127mm (5”), 140mm (5.5”), 152mm (6”) and 165mm (6.5”) are compared to assess the non-ideal confined shock-state work energies. The Non-Ideal Shock Energy Factor (NSEF), which is the available shock energy per cubic meter of blasted material (MJ/m3) or kilocalories per cubic yard (kcal/yd3), is used to compare the different blasting patterns charged with a range of ANFO-emulsion blends from zero to 50% emulsion.

Jan 1, 2012

By Panagiotis (Takis) Katsabanis, Lyall Workman, Jack Eloranta

The reduction of metallic ores to concentrate consumes a great deal of electrical energy. In the past two decades, a number of case studies have demonstrated a beneficial relationship between powder factor and grindability. However, changes in mill performance cannot be attributed to changes in feed size alone. Blasting energy and the distribution of that energy appears to affect subsequent comminution beyond crushing. This experience has prompted researchers to attempt to duplicate and quantify the mechanisms involved. To date, published reports indicate a measure of success. However, the blast engineer and the mill engineer still lack the tools and basic understanding necessary for full drill to mill optimization.

Jan 1, 2015

By Enrique Munaretti, Vitor Rosenhaim, Jair Carlos Koppe, Joao Francisco Feijo

The B3 mine is a multiple coal seam strip mining in operation in Rio Grande do Sul, the southernmost state in Brazil. A traditional truck & excavator operation is used to remove the overburden and selectively mine coal seams, ranging in thickness from 30 cm (1 ft) to 2.5 m (8.2 ft). Blasting is required in order to excavate part of the sedimentary rock overburden where the rock is too hard for mechanical excavation, and to mine the coal seams, selectively.

Jan 1, 2012

By Michael Milstein

Northwest Research Station said as more and more older dams are removed to benefit fish, it’s become clearer that rivers rework themselves quickly.“Where the dam is relatively small, it’s a quick response,” he said. “The river quickly forgets.”

Jan 1, 2010

By M V. Van Bers, A L. McAnuff, A Curic

During the Summer of 1997, rock excavation was carried out for construction of the Centre Block Underground Services building (CBUS) abutting the most historically significant structural complex in Canada, the Parliament Buildings in Ottawa. Controlled blasting was required for the removal of 25,000 cubic metres of limestone bedrock within the ten week time window of Parliamentary recess. A test blast program carried out in 1996 had established that close blasting was viable even within the very restrictive limits considered necessary to preserve the structural and cosmetic integrity of these historic structures. In total 300 blasting operations were required to complete the excavation, including the 20 test blasts conducted in 1996. Based on attenuation characteristics established for the site during the trial blast phase, the blasting contractor proposed excavating the CBUS site in three zones. Each zone contained differing drill patterns, depths and explosive loads. Vibration intensities, air concussion levels and displacements across representative existing cracks were measured and recorded at numerous observation points within and around the Centre Block and the Library of Parliament, as well as on the grounds of the Parliamentary Precinct. The blasting portion of the excavation was completed within budget in less than eight weeks, well within the tune window available. Comparison of very extensive pre and post-blast condition surveys revealed no damage to the existing structures on Parliament Hill as a result of these operations.

Jan 1, 1999

By Kwang-Yeom Kim, Dong-Gyou Kim, Hyo-Kwan Yoon

This study was intended to simulate the blasting model using notched-hole with numerical approach. Numerical analysis approach was applied to compare and evaluate the blasting model using notched-hole and circular hole. To implement non-linear dynamic blasting model, blasting analysis was carried out with AUTODYN code. Behavior of two models was compared and evaluated using AUTODYN and visual analysis and quantitative evaluation based on pressure and stress to verify the effect to induce the destruction territory to the specific direction when blasting with notched hole was attempted.

Jan 1, 2010

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 R. Ticona, J. Alarcon

In the continuous search to provide comprehensive solutions and identify opportunities to improve ore traceability, from the blastholes to mill feed, different ore traceability systems have been developed, which allow tracking the ore and associating its geometallurgical characterization of different sectors of interest from blasting to the processing plant, facilitating decision making and operational actions when detected during each stage of the plant. With the objective of improving the ore tracking from the mine to the processing plant in a Peruvian copper mine operation, the impact on the processing plant was evaluated in relation to blasting optimizations through a tracker system, relating the processes performance of the whole production chain with the geotechnical and geometallurgical properties ores in real time in the process plant: detecting when it was feed waste, high grade ore, low grade ore and ore with arsenic, among others. Unit and integral tests were carried out over a period of three months, with an implementation of tracker detection portals in the processing plant, which allowed to verify the proper communication of data and the web platform. The tests were focused on several blasts where the ore was in contact with waste and it were directly sent to the plant, with a classification by type of grade (high, medium, and low grade), type of material (ore-waste contour), this stage allowed to make operational adjustments in the field and in the mining operation. Finally, in the economic results, the special tests had 1000 trackers, obtaining for this project a sensitization of a cost benefit for the test stage, for the reduction of 50% of the waste material feed has crushed, with an estimated benefit of 1,987,646 USD.

Jan 1, 2024

By Alastair Torrance, Gary Cavanough

Approximately 1.5 million tonnes of ammonium nitrate are transported annually across Queensland, Australia—equivalent to nearly 100 truckloads per day. This is in the form of both AN prill and ammonium nitrate based emulsions (ANE). In a recent incident, a collision involving an ANE tanker resulted in a detonation that caused extensive blast-related damage and led to the closure of a major highway. Had this event occurred within a populated area, the consequences would have been catastrophic. For over a century, investigations into the causes of such spontaneous detonations have been inconclusive. A recently completed industry supported research project has made a pivotal discovery: a surface reaction mechanism leading to hydrogen generation has been identified as a precursor to detonation. If sufficient hydrogen accumulates and subsequently ignites, it can release enough energy to initiate the detonation of bulk ammonium nitrate and ANE. Controlled experiments conducted during the project successfully demonstrated hydrogen-driven detonation events. Previous work by Proulx and Scovira, presented at the 2000 ISEE Conference, described spontaneous detonations in hot, reactive ground and the mitigating effects of buffered emulsions and ANFO. Building upon their observations, this study reproduces similar incidents under laboratory conditions, confirming that hydrogen generation also results from reactive ground interactions. Importantly, the findings challenge traditional assumptions, demonstrating that ammonium nitrate and ANE detonation in reactive environments does not require an ignition temperature threshold, confinement, or a classical chemical decomposition pathway.

Jan 26, 2026

By Gregory Hempen, Thomas Keevin, Russell Wilcox, William Wild

The Department of Defense Strategic Environmental Research & Development Program (SERDP) awarded funding for evaluation of procedures to mitigate peak pressures and energy flux density in the water column from ordnance being detonated on the ocean floor. The research purpose was to conduct scaled testing to resolve whether a theoretically-viable covering technology was operationally effective in reducing blast effects and the impacts of shrapnel. An additional objective was testing effectiveness of this method for hard-bottom units (rock or coral) and (unconsolidated) sediment substrate.

Jan 1, 2011