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By Huang Daguang, Paulo Couceiro, Juan Navarro

Mining is typically conducted through a set of interdependent unit-operations, which commonly include drilling, blasting, digging and hauling, in order to deliver the required ore material into the comminution circuit and to remove waste rock with minimum impact in the operation. In such complex environment, the identification of critical paths, and respective interfaces between different unit-operations, are necessary to determine a sustainable long-term operational program. Facing this challenge, adaptive cost optimization strategies are required to increase productivity and revenue while minimizing potential environmental impacts. Since the overall mining efficiency can be strongly impacted by blasting outcomes, an operating method based on the searching of the ideal blast design is required in order to minimize the mine total cost of ownership. The implementation of a consistent continuous improvement program requires specific care in terms of design, control and execution of the different stages of blasting. For that, the application of the most advanced technologies for rock characterization, based on drill monitoring systems, and smart explosive products, allows the improvement and control of blast results by adapting the explosive energy distribution to the rock condition, so as to optimize the performance of downstream stages such as digging, hauling and comminution. This paper describes the application of a heuristic optimization approach, where blast parameters are used as decision variables to evaluate the potential impact of several blasting scenarios on subsequent unit operations, under the continuous ability of modelling, measuring and calibrating operational performances along of the mine cycle.

Feb 6, 2023

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 Enrique Munaretti, Cathy Aimone-Martin, Vitor Rosenhaim, Jair Koppe

Production blasts at one of Copelmi’s coal mine operations will be carried out 100 m (330 ft) from a neighborhood located in the town of Butiá, southern Brazil. Mine management is concerned about the possibility of damages and complaints due to blasting operations at close distances to structures of substandard construction. Blasting in the area is characterized by the use of very low powder factor resulting in confined shots in which movement is restricted to a point of almost undershooting the rock. Over the past year, tests were conducted mainly in the overburden area to determine the best approach to be implemented when blasts move closer to the town. Mine management wants vibration levels to be reduced lower than the damage limits proposed by Brazilian regulations to ensure a safety margin and mitigate perception by the community hoping to reduce the number of complaints.

Jan 1, 2013

By Ali Kahriman, Olivio Angelini, Ibrahim Sefer, Burak Ekmen, Koray Arpak, Ertugrul Kaya, Yucel Karakus, Abdullah Sak, Aziz Ozdemir

In recent years, in order to bring solution to traffic intensity arising from transportation problems and facilitate public transportation in the modern world in paralel to urbanization and to the increase in population, it’s well known that, the construction of Access tunnels is inevitable. The driving of the tunnels is a subject of special interest in the technique of rock blasting. The essential factors in terms of tunnel driving and safety in tunnel blasting that is applied in metropolitan areas, an in depth knowledge of ground vibrations and the ways of reducing them to safer levels.

Jan 1, 2010

By Svatopluk Zeman, Zbynek Akstein, Jiri Pachman, Ahmed Elbeih, Marcela Jungova

BCHMX (cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole or Bicyclo-HMX) was studied as an energetic component of three different plastic explosives based on three matrices: C4 matrix, semtex10 matrix and silicone matrix. The original plastic explosives, Composition C4 - based on RDX (1,3,5-trinitro-1,3,5-triazinane), Semtex 10 explosive based on PETN (pentaerythritoltetranitrate) and plastic RDX-silicone, were included for comparison. Sensitivity and performance parameters were studied.

Jan 1, 2011

By D J. McLane, J T. Rathbun, B T. Lusk

The dynamics of explosive detonations are understood, however recreating a real-world, full scale scenario is costly. The use of a shock-tunnel allows testing to be done on a smaller scale, with the simulated effect of a large explosion. Analyzing explosive waveforms using this method can greatly reduce cost in testing blast resistant products, such as anti-terrorism devices, mine safety products, and military equipment. The purpose of this paper is to better the understanding of how the waveform characteristics resulting from an explosive detonated within a shock-tunnel differ from those in an open-air arena test. The variables of comparison between an open-air arena test and those conducted within a shock tunnel are peak pressure, impulse, shock wave velocity, and cross sectional shape of the shock front. Understanding how these variables differ, tests utilizing a shock tunnel can be conducted with a higher degree of accuracy and repeatability.

Jan 1, 2013

By Alan Diaz Butron, Eng. Thierry Bernard

"In tunnel blasting the most challenging objective is definitively obtaining the maximum advanceassociated to a minimum overbreak. Achieving 100% of advance with no overbreak is the targetchallenge by Chavimochic Consortium. Chavimochic Special Project is an irrigation system that extends throughout much of the coast of the La Libertad Region, on the north coast of Peru. In 2012, it began management for construction of the third and last stage of CHAVIMOCHIC to irrigate lands of Chicama Valley, North of Trujillo. This project of 13 Km (8 mi) of various tunnels, it's a combination of technology and daily optimization by experienced people, which allow to accomplish the objective. Achieving this advance with no overbreak provide a huge saving on time. This paper describes the method, technology used, and the results obtained on more than 600 blasts done with conventional initiation system on the first 3 km (1.86 mi)."

Jan 1, 2017

By Robert Hopler

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its importance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes.

Jan 1, 2012

By Joshua Hoffman, William Chad Wedding, Braden Lusk

The emergence of electronic detonators as viable products for use in production mine blasting has enabled mining professionals to rethink the traditional blast design methodologies that pertain to timing. In many ways, electronic detonators can allow great advances in productivity, cost effectiveness, fragmentation, and safety. There are a number of commercially available systems that enable users to program delay times, usually in one-millisecond intervals, according to design decisions. While manufacturers have performed internal studies pertaining to the accuracy of these systems, an independent study quantifying the accuracy of the systems has not been completed to date. The mining industry is in the business of production and any quality control endeavors to independently confirm the accuracy studies performed by the manufacturers would only detract from their bottom lines. Furthermore, limited information is available concerning the accuracy of modern pyrotechnic delay based detonators. In 1985, the Bureau of mines completed a study of three manufacturers’ electric millisecond delay detonators (Bajpayee, 1985). This was the most recent extensive independent study performed on detonators, which unitized pyrotechnic delays, from numerous manufacturers. Advances in the manufacturing process for pyrotechnic delays may have increased the accuracy of detonators using these technologies in recent years. It is commonly accepted that electronic detonators are more accurate than both shock tube type non-electric as well as electric detonators, but the relative accuracy was not objectively and adequately quantified.

Jan 1, 2011

By NA NA

Copyright © 2020 International Society of Explosives Engineers

Feb 1, 2020

By John Montgomery

This paper discusses the major changes to the Commissioners Rules and Regulations, Chapter 120-3-10 “Rules and Regulations for Explosives and Blasting Agents”; how the changes came about, and a summary of the status of the blasting industry in Georgia.

Jan 1, 2003

By Tyler Acorn, Paul Worsey, Nathan Rouse

The effect of the hole diameter on vibration attenuation has not been incorporated in most vibration models in the blasting industry. In current vibration models, the charge weight and the distance from the blast are the two primary variables that are addressed. Charge weight is a function of explosive density, charge length, and charge diameter. This geometry-weight can complicate the isolation of the charge diameter variable.

Jan 1, 2013

By Aris Tambunan, Nella Lubis, Nurafrianti Saala, Komang Widhiayanto, Herry Saputra, Rudolf Sitorus

Maximizing mining recovery rates and minimizing ore loss are pivotal objectives for economic efficiency and operational effectiveness. This study explores methods to address these imperatives by enhancing ore production and recovery through improved blasting techniques and spillage control in the Martabe Gold Mine Project in North Sumatra Province, Indonesia. Between 2018 and 2021, the average mining recovery rate stood at 93%, resulting in a potential annual ore loss of 7% and a potential quarterly financial impact of close to $2 million. Maintaining and enhancing mining recovery became crucial, with a planned 30% increase in total material movement for 2022. The mining recovery target for 2022 was set at 96% based on best achievement historical data from 2021 to increase ore tonnage by 203 KTon per annum. To achieve the primary objective of increasing ore production by improving mining recovery, the study focused on predicting and controlling the movement of blasted ore to reduce spillage and enhancing the grade control model to reflect actual conditions post-blasting. Several alternative solutions were explored, primarily emphasizing drilling and blasting activities. Essential methods included capturing the actual blasting movement to adjust the ore block based on blasting design data and post-blasting muckpile topography. This approach minimizes ore loss by providing output as ore block adjustment based on post-blast movement data. In addition, the tie-up design was adjusted to control ore spillage outside the pit ridge. The implementation of these methods yielded significant improvements. Adjusting the ore block based on actual blasting movement contributed $1,545,764 in benefits. Controlling ore spillage outside the pit ridge achieved a 10% reduction in spillage, contributing $79,184 in benefits. These enhancements successfully met the 2022 mining recovery target of 96%, marking a 3% increase from 2021. Consequently, ore loss was reduced by 178 KTon throughout 2022, resulting in a financial impact of $7.3 million. The study underscores the significance of precise blasting techniques and effective spillage control in enhancing mining recovery rates.

Jan 21, 2025

By Sedat Esen

"This paper presents a critical review of the fragmentation data obtained from some large open pit copper and gold mines. Database ncludes 35 mines with Uniaxial Compressive Strength values ranging from 19 MPa to 227 MPa (2756 psi to 32923 psi). Variation in the fragmentation data and the causes are discussed in detail. Quality assurance/quality control (QA/QC) in drilling and blasting was shown to have significant impact on fragmentation. In addition, controllable blast design parameters including drill pattern, powder factor, blast timing, stemming length, etc as well as the large blast sizes havesignificant potential to improve fragmentation. Feed size requirements of crushing and grinding circuits were discussed in detail. The paper discusses the effects of different size fractions (top size, 80 %passing size and % passing 10 mm (0.5 in)) on the downstream processes and the role of the fragmentation model in the mine to mill process. Blast domains based on rock strength and structure canbe established by using a fragmentation model which is calibrated using measured fragmentation data. This allows the blast engineer to compensate for changing rock characteristics and stabilize the ROMfragmentation size and result in increased crusher and mill throughput. Two case studies were presented to demonstrate the benefits achieved in downstream processes. Main benefits were reduced downtime at crusher circuits, improved mill throughput as well as reduced total operating cost. A simple relationbetween uniaxial compressive strength and powder factor was proposed using the database for the optimized mines as a guideline to allow site engineers to compare their sites against the other sites."

Jan 1, 2017

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

"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 Thomas M. Keevin, Gregory L. Hempen, David J. Schaeffer

In an attempt to reduce the potential for fish mortality during the explosive demolition of Locks and Dam 26, Mississippi River, the U.S. Army Corps of Engineers, St. Louis District explored the use of a bubble curtain to reduce the fish kill radius of underwater explosions. Bubble curtains are walls of bubbles rising from a bottom-resting bubbler manifold supplied with compressed air. Demolition engineers have long been aware of the attenuating properties of air bubbles in water. As such, air curtains have been routinely used to protect underwater structures from damage by underwater explosive shock waves. However, their use in protecting aquatic resources during full-scale explosive demolition projects was untested.

Jan 1, 1997

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 Barbara Rutter, Shonn Kevin McNeil

"This study discusses how a prototype was built to measure the sonic velocity in powdered explosives.The sonic velocity of an explosive is a benchmark to determine if the explosive deflagrates or detonates;however, little work has been done to determine this value for powdered explosives. This paperdiscusses the results of the initial prototyping tests where two known mediums, air and water, were used for validation. The prototype did record the sonic velocity within the known velocity ranges of air and water; however, a few depths did not fall into this range. This prototype could be used for testinggranular materials."

Jan 1, 2017

By Lazar Kricak, Vladislav Kecojevic, Dragan Bogunovic

In spite of many advantages explosives have, their usage may cause environmental problem such as seismic vibration. One of the solutions to this particular problem may be application of an artificial screen as a barrier to the seismic wave path. This paper presents the results of experimental research on the artificial screen concept, its characteristics and role in attenuation of seismic effects generated by blasting. More than 1,500 laboratory measurements were conducted with different combinations of screen sizes, positions of the screen to blasting source, and intensities of blasting impulses. The results of the study show a significant reduction of generated vibrations by employment of artificial screens.

Jan 1, 2007