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By Lawrence Mirabelli, AngloGold Ashanti, Greg Gibson

Cripple Creek & Victor Gold Mining Company (CC&V) operates the largest surface gold mine operation in Colorado and is located west of Colorado Springs in Teller County between the towns of Cripple Creek and Victor. Gold was first discovered in the Cripple Creek mining district in the 1890s. CC&V has been conducting gold mining and precious metal extraction operations in the Cripple Creek Mining District since 1976. Current reserves are only amiable to surface mining since previous underground mining has depleted near surface ore rich veins.

Jan 1, 2014

By Stephen Mansfield

In open-pit mining operations, the drill and blast processes have a significant impact on the downstream operational performance of crushing and grinding of ores and recovery of metal. The blast pattern parameters, combined with the material properties, defines the run of mine fragmentation, which in turn drives the subsequent energy requirements for further processing and mill throughput. A common parameter used to describe a single hole or collection of holes is powder factor, the ratio of explosives to the quantity of material blasted. One often-neglected aspect of calculating powder factor is the explosives contained within the length of hole drilled into the top of the bench from the previous bench, known as subdrill. Explosives in the subdrill directly affect the bench below and thus do not contribute significantly to the results of the upper bench, even though they are traditionally included in the powder factor calculation. This paper presents geospatial data modelling methods that link individual holes from an upper bench to the bench below. This enables a new method for the calculation of powder factor, whereby the explosives in the subdrill from the bench above are included in the powder factor calculation of the bench below. This method allows for a clearer understanding of the impact of subdrill on fragmentation, and how variations in blast designs in the upper bench, i.e. hole diameter, burden, spacing, subdrill length, explosive type, primer position, etc., and accuracy of implementation, i.e. actual hole depths and explosive mass per hole, affect the powder factor and blasting results in lower benches.

Feb 6, 2023

By Charles Zdazinsky

"The Multiple Seed Waveform (MSW) blast vibration model, a type of waveform superpositionmodeling developed by Orica Inc., uses vibration data that is collected from a signature hole blast tocharacterize the ground’s seismic properties and determines the ground resonant frequency andfrequency range that is well supported by the ground. Additionally, the MSW model uses thisvibration data as input parameters to predict the resultant dominant frequency of a production blast. This information may in turn be used in conjunction with precise timing control to target theoptimum dominant frequency which promotes ground control."

Jan 1, 2016

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 Tristan Worsey

This work was performed during the summer of 2008 during the junior year of a BS in Mining Engineering. It was observed that the mine was having a problem with back break during the blasting of development drifts. The unwanted back break was causing the mine extra costs in ventilation, ore dilution, ground support, back fill, explosives and man-hours. The blasting practices were observed for four weeks and the problems and their solutions were defined. In this paper the reasons and causes of the problem are explained with the proposed solutions to eliminate back break.

Jan 1, 2010

By Jorge Blázquez, Paulo Couceiro, Patricio Vergara, Luis Martínez, Juan Navarro

This study introduces the X-2Mill solution, a refined two-step methodology aimed at optimizing blast designs by aligning explosive energy with rock properties. The approach employs the X-4Traits Model, which uses drill-monitoring data from both autonomous and manual drilling modes to develop two critical indexes: the Drilling Rock Factor (DRF) and the Drilling SAG Power Index (DSPI). The DRF integrates the Size-Energy Fan Model with rock fragmentation results and blast design parameters, while the DSPI adjusts Specific SAG Energy (SESAG) based on Bond’s theory, incorporating ore X80 results, SAG mill capacity (TPH), and power draw to estimate milling difficulty. To enhance prediction accuracy, the X-2Mill solution incorporates, to a Principal Component Analysis of the normalized drilling data, a Meta Machine Learning model with a 3D spatial function, accounting for information from surrounding drill holes. This integration improves the precision of the DRF and DSPI estimates. The methodology unfolds in two main steps: Step 1: Bench-Scale Pattern Design, involves defining the target P80 size for ore based on the SESAG and the DSPI. It also establishes target X80 sizes for waste and oxide materials and iterates to determine the optimal Burden x Spacing (BxS) using the Size-Energy Fan Model and the DRF. Step 2: Blast-Scale Selective Explosive Density/Energy focuses on refining explosive density on a hole-by-hole basis to achieve the specified X80 values for ore, waste, and oxide materials. The X-2Mill Solution was developed at Minera Escondida Limitada (MEL) using data from 162,761 blastholes across 356 blasts conducted over three mine expansions. This solution addresses the challenges of blasting harder and more difficult rock, particularly in the lower levels of the mine. By adapting the blast pattern and explosive density to the specific rock properties and ore/waste designation, the X-2Mill Solution aims to achieve precise size distributions and improve overall blasting performance. The results demonstrate that the X-2Mill Solution balances ore fragmentation to meet SAG mill throughput requirements while optimizing powder factor costs for waste material and maintaining digging efficiency. By efficiently distributing explosive energy, the solution not only enhances throughput but also improves blasting efficiency while ensuring stable slopes and minimizing fault activation.

Jan 21, 2025

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 Dale S. Preece

A new three dimensional (3D) mechanistic model of fragmentation, called the Fracture Density Model (FDM) is used to simulate full-scale bench blasts at the Bararp dimensional stone quarry in Sweden. The model uses several computational mechanics algorithms to simulate the effect of blasting in different rock types

Feb 1, 2020

By Robert Hopler

RBH Note: The Illinois Powder Manufacturing Company was established in 1907 and was acquired in 1957 by American Cyanamid. The latter company left the explosives business in 1969.

Jan 1, 2010

By Tristan Worsey, Brad Gyngell, Todd Buschjost, Gus Diehr

This paper highlights the opportunities provided by integrating MWD data and drone generated 3D model to industries that use explosive energy to perform useful work as an integral part of their rock extraction process.

Feb 1, 2020

By Ravi Sahu, Ankit Jha, Sudarshan Rajagopal, Purushotham Tukkaraja

Geologic structures are one of the crucial parameters in blast design. Structural geology and rock properties influence drilling patterns, blast layout, and initiation systems. A comprehensive understanding of structural characteristics is essential to achieve the desired blasting objectives. This paper aims to identify geologic features in a bench using images obtained from the drone.

Feb 1, 2020

By Jeffrey Meissner, Charles Dowding

Cracking is one of the concerns cited by owners of structures adjacent to construction or mine blasting. During the past decade a large number of measurements have documented the low level of crack response produced by typical, ground motions compared to those produced by climatological effects. These data support the observation that there is a level below which ground motions do not cause even cosmetic cracking. As with all new findings, these crack response measurements need to be thoroughly investigated for all possible alternative interpretations. Among these alternatives is that uncracked locations are more affected than cracked locations. This paper presents measurements to shed light on the influence of existing cracks and the response of uncracked, but weak locations. Blast and weather induced responses of cracked and uncracked areas of gypsum wall board are compared in two structures: one near a surface coal mine in Indiana, the other near a limestone quarry in Florida. The ground motions that excited one of the structures were unusual in that the dominant excitation frequencies of 5 Hz were near the structure’s natural frequency and amplitudes exceeded 0.7 ips (18mm/s).

Jan 1, 2011

By Gabriel Gonzalez, Paulo Couceiro, Luis Manriquez, Alejandro Gutierrez, Juan Navarro

A high-stakes blasting campaign was successfully executed at a major open pit copper mine in northern Chile. This operation posed a significant technical challenge due to its immediate proximity to the tailings dam - a critical infrastructure whose structural integrity depends on strict control of blast-induced seismic vibrations. The geological complexity of the area, characterized by upper andesite interbedded with caliche (carbonate), further complicated the operation. This lithological composition, known for its high tenacity and cohesion, posed additional challenges for achieving effective fragmentation, necessitating a highly customized blast design and loading strategy. The campaign included four production blasts and one secondary blast, all executed under the constraint of not exceeding the Peak Ground Acceleration (PGA) threshold of 0.64g, as defined by the Maximum Credible Earthquake (MCE) scenario. To ensure compliance, geophones were strategically installed at three monitoring points (P1, P2, and P3) on the dam to capture real-time acceleration data. The use of specialized blast patterns, precise stemming control, and electronically sequenced detonations ensured that all recorded accelerations remained well below the critical threshold. A total of 496,163 tonnes of material were safely blasted, with 8,452 meters drilled and powder factors ranging from 419 to 594 g/ton. Therefore, this case study exemplifies operational excellence in controlled blasting, demonstrating the feasibility of safe mining near geotechnically sensitive zones through predictive modeling, rigorous QA/QC, and post-blast analysis.

Jan 26, 2026

By E. Lentilucci, A. Dey, X. Liu, A. Datta, S. Ghosh

The segmentation of quarry blast smoke plumes is a crucial research area that has the potential to enhance safety, environmental monitoring, object detection, and regulatory compliance in the mining industry. Smoke plume segmentation can be used to identify the spatial extent and temporal evolution of smoke plumes generated by the blast. This information can be used to improve the understanding of blast dynamics and optimize blast designs. Furthermore, smoke plume segmentation can assist in identifying potential environmental and health hazards associated with the release of smoke and dust particles into the atmosphere during quarry blasts. However, many current smoke plume segmentation algorithms are designed for segmentation of smoke plumes from fires and are not suitable for segmentation of plumes from quarry blasts. The proposed method in this paper leverages the video frame captured before the blast as a stationary background image, which helps to reduce other confuser objects present in the image along with a selfadaptive clustering method. The color channels of the image are utilized based on the different contrast properties of the smoke, with a self-adaptive gradient compensation applied for edge detection of the smoke plume. This approach offers a novel and effective way to segment smoke in quarry blast analysis, with potential applications in the calculation of noxious gas volume and concentration within the plume. Compared to other algorithms, our method improves accuracy, decreases the false alarm rates, and reduces the overall miss rate. Overall, this paper contributes to the research on smoke plume image segmentation, particularly for quarry blast smoke plumes, which possess unique characteristics that require specialized algorithms for accurate segmentation.

Jan 1, 2024

By D. Scott Scovira, Remi Proulx

The Meikle Mine is a high grade, underground gold mine utilizing primary-secondary longhole open stoping with delayed backfill to produce 3000 stpd of ore. Hot and reactive ground conditions were encountered early on in the mine life. Ground temperatures up to 330” F were measured. In the early stages of mining, the mine experienced premature detonations using different explosives. The learning curve to safely mine this high-grade gold deposit in hot and severely reactive ground was indeed very steep. Currently, the Meikle Mine uses a special buffered bulk emulsion in all blasts to address hot and reactive ground concerns. In addition, exacting procedures are also followed to ensure safe work with explosives. The combination of new explosives technology and strict loading procedures permits high mine productivity with the highest degree of safety.

Jan 1, 2000

By Johan Finsteen Gjødvad, Mathias Jern

The paper is part of the ongoing work of the Environmental committee of EFEE. To assist the European experts working with explosives one of the aims is to improve the common knowledge of similarities and differences between national legislation, standards or guidelines on vibration monitoring and other environmental monitoring during blasting in Europe and abroad. This has been done by use of an online survey through the most of 2018. Questions have been raised on vibration monitoring during blasting. The existence of norms, guidelines or standards and how they are used. Even though the questions have been kept at a high level they are formed to try to map the different national standards use of such things as frequency, guidance on monitoring position, distinction between different types of structures, requirement to the equipment and more. Furthermore a few initial questions have been raised on other environmental monitoring relevant for blasting. The respondents are national, cooperate or individual members of EFEE. The answers are experts in the use of explosives and vibration-monitoring in their respective countries. More than 60 have answered the questionnaire from 29 different countries. Mainly European as well as other nations including India, Israel, Nigeria, Saudi Arabia, UAE, USA, Greenland and Hong Kong. By analysing the incoming answers, the differences and similarities in vibration monitoring of the respondents has been clarified and mapped. Where possible other environmental monitoring has also been analysed. Where needed the different guidelines, standards and regulations have been visited to verify the answers and further elaborate on the comparison.

By Norman Paley, Zachary Pickett

The Red Dog Mine is a high-grade zinc-lead mine located in northwest Alaska which began operations in November 1989. In June 2014 the upper half of a charge in a trim shot in the Aqqaluk pit deflagrated. No other holes in the area were observed to react and the remainder of the pattern was shot without incident. This was the only known case of a deflagration in the 25 years of operations. As part of the investigation into the cause of this incident rock samples were obtained from the area of this hole and from other areas in this pit.

Feb 1, 2020

By David S. Shatzer, Michael R. Purcell

Current world events have demonstrated the use of commercial vehicles, other unconventional modes of transportation and unusual materials as explosives or incendiary weapons, affecting commerce, disrupting cities and even entire societies. Since the implementation of the Organized Crime Control act of 1970 the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has been investigating and studying explosives and incendiary devices and their related effects.

Jan 1, 2004

By M. Y. Wong

Electronic detonators have been used on a trial basis for over a decade, and found more recent application in production blasting as well. The relative merits of these detonators and their applicability are outlined through examples from actual blasting operations. They offer unprecedented flexibility in the design of mass blasts and in control of vibration and blast-induced damage. However, the drive towards replacing the pyrotechnic detonators by electronic ones in general could prove to be counter productive without a re-examination of prevailing blasting practices. In fact, such an approach tends to blur the tremendous potential of the electronic detonators in redefining many standard blast designs and practices.

Jan 1, 2004

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