Search Documents

By Alejandro Ferrada Vergara, María Jesús Barros Godoy

The need for a basic method for selecting explosives based on rock mass or intact rock properties for mining and construction arises from the limited consideration given to these factors when choosing among products and also an implicit overestimation of the explosive power to fragment the rock. This study highlights the importance of evaluating different properties such as rock strength, deformation, fracturing, detonation velocity and energy release when selecting explosives. The concept of characteristic impedance, which considers rock strength against shock waves generated by explosive detonation, is introduced. Understanding this concept is crucial for assessing explosive behavior according to various rock types. The study concludes with a practical guide table that categorizes rock properties and provides recommendations for selecting explosives based on rock mass and rock properties. However, it is important to consider other relevant factors, such as the presence of water or nearby instabilities, which can influence the final choice of explosives.

Jan 21, 2025

By Roger N. Prescott

This report presents a new process in delay blasting with the use of ANFO and slurry explosives.

Jan 1, 1977

By Zhang Zhenyu, Wu Xinxia

The blasting quarrying technology of rock material of rock-fill dam is one of the more complex problems in the field of engineering blasting at present. The Kuz-Ram model is not suited to predict fragmentation distribution under the geology condition of Tianshengqiao(TSQ) fist-step power station. The modification of kuz-Ram model is discussed. With reference to the idea of model establishment of Kuz-Ram model and according to the results of experimental blasting in-situ, two fragmentation prediction models-TSQ-1 and TSQ-2 model are presented which are adapted to the particular condition of rock material querying blasting of rock-fill dam with concrete facing of TSQ first-step power station. The rapid judgment method of qualified grade material and the method of optimizing blasting parameters are also presented in this paper.

Jan 1, 1998

By Hairong Zeng, Shahram Tafazoli, Edmond Chow

Blast fragmentation is one of the main parameters for optimizing mineral processing, but reliable data is difficult to acquire, resulting in unpredictable performance and efficiency. Crusher and grinder circuits are designed to process specific rock size ranges. Oversized rocks require extra energy to reduce before feeding into the process, and undersized rocks indicate that the process is not used to its full extent. Blast design is the key to controlling the blast fragmentation, so the ability to accurately monitor the particle sizes is imperative.

Jan 1, 2011

By L. Chaves

In rock blasting, due to numerous factors, both controllable and uncontrollable, the execution rarely meets the planning. The powder factor is an important KPI for blasting since it represents the amount of explosive used to fragment the rock, therefore it depends on the rock mass characteristics and may be influenced by factors such as weathering and drilling quality. The blasts at the Serra Sul mine, S11D project, are usually big blasts and the high productivity is a challenge for maintaining the quality of the whole drill and blast process. It is important to know the contributions of each of the most common influencing factors of the powder factor to direct the efforts to the improvement of the process. A buildup model is presented to evaluate the contributions of five influencing factors to evaluate the planed x executed powder factor. The factors considered in the model are the average hole depth, the amount of hole/blasted volume, the stemming and decking length, the linear charge weight, and the density of the explosive used. The build-up may be applied for both individual blasts and for overall view of the blasts in a period. A case study is presented with the application of the model for the monthly powder factor analysis at Serra Sul mine has contributed to direct efforts to enhance drilling quality and preservation of the drilled holes.

Jan 1, 2024

By Orica Peru, Pedro Lozada

Maintaining a continuous mining process during thunderstorms is one of the primary challenges in Peru's open-pit mines. Safety protocols necessitate the establishment of exclusion zones to minimize the risks of unplanned detonations. During such conditions, loading and hauling equipment must be relocated or, in the worst case, halted, directly affecting productivity (t/h). Implementing a wireless initiation system mitigates the risk of unplanned detonations during electrical storms by eliminating the use of electrical cables that are susceptible to electrical discharge. This study documents the implementation of this system in a copper mine located over 3,500 meters above sea level in Peru, where electrical storms between December and March necessitate modifications to blasting schedules and limit the number of drills fired per event. Through a test using wireless detonators, a key performance indicator (KPI) was established to ensure safe and continuous operation during thunderstorms. The results were significant: 20 blasts were successfully executed, firing approximately 5,000 holes and moving around 10 million tons of material, all without safety incidents or critical operational deviations, achieving zero misfires and no scheduled blast suspensions. Shovels SH001 (ore) and SH002 (waste) continued to operate together for an additional 100 hours continuously during thunderstorms, generating a potential saving of USD 3.3 million by continuously sending ore to the plant during the testing period under stormy conditions. Additionally, the blasting initiation time was reduced by 25%, eliminating two activities that involved the use of surface connection cables. This reduction led to over 150 hours of decreased personnel exposure to interactions with vehicles and environmental hazards such as dust and noise. Furthermore, the number of holes fired in a single event increased by 50%, enhancing the blast tonnage capacity and reducing equipment stops due to evacuation and reentry from two to one.

Jan 21, 2025

By Stuart Brashear, Steven Bell, Donald Smith

This Limestone site required the removal of a bench containing high quality rock located in close proximity to sump and pit pump. The sump and associated electrical box were below the bench that needed to be blasted and located only 70 feet (21.33 meters) away. It was proposed to blast material needed without moving or disturbing the pump or electrical junction box. The area to be blasted was flown with a drone and stitched into a 3D orthographic model. Proprietary blast design software was used to create a blast design solution that would allow for a series of blasts that would provide required fragmentation and muckpile development and not disturb the sump or electrical box. A drill patten was created for each blast using the burden heat map and 3D face profiles created from the 3D orthographic model. Timing contour lines and muckpile displacement predictions were used to create timing sequences for proper face movement away from the sump and electrical box. The shot designs were laid out with a GPS system to insure hole location accuracy. All holes were remeasured for proper face burdens using the 3D model and Boretrak®® data collected after drilling operations were completed to insure hole locations were within face burden tolerances as derived by the burden heat map. After each drill log was reviewed, a charge loading scenario was created for each hole. The timing design created, for each shot and was reviewed and adjusted as needed with regard to desired muckpile displacement away from the sump and electrical box. Blasting results were satisfactory, with fragmentation and muckpile development consistent with the calculated throw from the blast model, with no rock hitting the pump or box and no rocks striking the sump water and disturbing the pump motor.

Jan 21, 2025

By R. J. Cefalo

Blast and mining spillover between phases or critical areas of the pit is a continuing problem in the mining industry and a safety concern for operating mines. The challenge for many mines is to produce the highest value in the shortest amount of time for any project. For any project, the top priority of any mine is producing ore as fast as possible. The next challenge is to keep that ore feed continuous. To achieve continuous ore feed, pits are designed with multiple phases that are connected and are mined at different elevations. This difference in elevation causes dangers with spillover between the phases during mining, drilling, and blasting. This paper covers an incident that occurred at an active mine and the work completed in creating a spillover control program over an active mining phase. The drill and blast technical group was responsible for creating blast patterns to reduce spillover between these phases. Unrealistic goals and expectations were initially set for the area of the pit. The drill and blast technical group needed to figure blast objectives and work with the geotechnical team to align with these goals. This paper will go over the executed example of setting up spillover targets and expectations for multiple sections of an operating mine. Different sections of the pit had different control measures and blast objectives due to narrow laybacks and double benching. The use and value of blast objectives and goals were beneficial in setting expectations and measuring design success. Having unrealistic blast goals can set up the operations to fail or get frustrated in trying to work on an impossible task. The problems and risks of phase interactions for many open pit operations need to be considered in the design process, along with designed controls that minimize the probability of any safety incident. Mine designs are being created in the industry and do not consider phase-to-phase mining interaction and the impact it would have on safety or production. The best future for safer mines is blast patterns that reduce spillover between phases of mining and pit designs that might account for spillover interaction.

Jan 1, 2024

By Felipe França Sitonio

Parameter’s control of explosives used in blasting operations have become more relevant over the years, bringing a better understanding of detonation performance. Giving into consideration that bulk emulsion density’s variation reflects directly on blasting results due to its importance in product sensitivity and velocity of detonation (VOD), blast designs are conducted assuming that cup density measurements are reliable and explosives gassing agents will perform as per specifications. Nevertheless, confinement conditions in boreholes like temperature, presence of water and surrounding circumstances of rock mass are often neglected on predictive modelling and off-site measurements. This paper describes the assembly of a device equipped with pressure sensors and its utilization in confined boreholes of an open pit mining operation, aiming to obtain in situ monitoring of density variation in several explosive columns. After we developed a software to get and process data of a hardware prototype and the device functionality was validated in water, oil and quarry mining experimental trials, 7 of 291 boreholes in a gold mine operation were chosen to be monitored with two probes each, placed at the top and at the bottom of the explosive column profile. The results obtained enabled a comparison between the bulk emulsion density variation when acting in different environments, since we selected boreholes with diameter of 101.6 mm (4 in) and 139.7 mm (5.5 in) and some with presence of water. Besides the increase of explosive density with depth related to hydrostatic pressure increase, we found an overall error of 6% in cup density measurements when compared with sensors placed at the bottom of boreholes and 2% when compared with sensors placed at the top of explosive column. These findings provide detailed insights into how bulk emulsion explosives behave in different circumstances including depth and borehole diameter, giving the opportunity to re-evaluate blast design parameters such as its geometry, sequence pattern, charging profile and explosive composition.

Feb 2, 2020

By Bethany Witter

In the past decades, a technological explosion has caused generational shifts. First, millennials experienced a technological shift to computers and cellphones. Next, Generation Z experienced a shift to smart phones and social media. These two generations are immersed in technology and are accustomed to constant connectivity. How do the extractive and construction industries gain the interest of younger generations and integrate them into the industry? The Virginia Tech Student Chapter of the International Society of Explosives Engineers handled this same issue with its recruitment efforts and event planning from 2017-2019. The first critical component of integrating Generation Z college students into the extractive industries is clear and frequent communication via email. Next, Generation Z often values the motivation behind work when choosing a career, so advertising technological advancements, benefits, and ways people can contribute to improving the industry also helps attract young generations. Similarly, advertising opportunities for people to work outside with their hands, travel, and secure stable careers can attract students. At Virginia Tech, the most effective way to attract and maintain the interest of students in extractive industries is to put the students in the field. Field trips to mines and factories experienced the most stable attendance and highest survey reviews of all other chapter events. Guest presentations from industry professionals were often well attended, but attendance tapered off as the academic year progressed and students grew busier. Periodic trips throughout the year maintained student engagement and often supplemented their curriculum. The student chapter was relatively successful in attracting students, but it struggled to maintain attendance levels in the latter portion of the academic year. In the future, the industry can increase its recruitment of Generation Z and Millennials into the workforce by working more closely with university programs to provide resources and opportunities for hands-on experiences for students.

By Ronald Ticona

Generally, the drilling and blasting operation are managed independently to the processing plant outcomes. Therefore, the technical segmentation to determinate the ore drill and blast designs do not include processing plant rock properties such as Bond Work Index, Axb, Drop Weight Index or other. This work describes the case study of a copper mine in Peru, which, together with its strategic partner ORICA, have implemented projects focused on optimizing mine fragmentation. The year 2021, mine operation according to its mine plan would have a significantly increased SAG mill hardness, which would impact directly on copper concentrated production. An integrated strategy from mine to plant has become necessary to maintain the production levels.

Feb 6, 2023

By Joe Atalla, Leojenen Etulle, Jesse Desrochers, Joseph Mukendi Kabuya, Remi Proulx, Ruilin Yang

The Mont-Wright mine is Canada's largest open-pit iron ore mine with multiple open pits in operation. It is operated by ArcelorMittal Mining Canada in the northeast of the province of Quebec, near the town of Fermont. Fragmentation of rocks with explosives generates vibrations and gas expansion that damage intact rocks, affect existing crack networks, reduce the shear strength of discontinuities and the quality of the rock mass of the highwalls. The efficiency of its blasting operations is challenged by the need to optimize production and manage the risk of mine slope instability caused by vibrations from successive blasts. This paper presents a Multiple Seed Waveform (MSW) vibration model that was established at the mine for this purpose. Near-field signature hole blast vibration monitoring was conducted in multiple areas to establish site characterization as input to the blast vibration modeling at the highwalls of the site. The vibration attenuation laws were established and the effects of different blasthole diameters, shifting frequencies and presplit design were evaluated. Based on the results obtained from the near-field blast vibration monitoring, the calibrated MSW vibration model was used to select blast design parameters to control blast vibration while maximizing productivity of blasts at Mont-Wright mine.

Jan 26, 2026

By Luis Huaroc, Augusto Sotomayor, Erick Rodriguez, Paulo Fernández, José Ricaldi, Luis Alejandro

The application of the Kuz-Ram model for the prediction of fragmentation is used worldwide, in Coimolache Mine it was used to determine blast domains and optimize the process by obtaining drilling patterns that meet a required X80 and reducing the uncertainty of drilling.

Feb 1, 2020

By David Flores, Benjamin Cebrian

This paper describes extensive engineering approaches to achieve both dilution control while not hurting fragmentation in the very hard, massive ore sections of a mine case study. Ore Tracker microchips are used to correlate performance of these designs at the SAG mill (bottleneck of this specific operation). Another gold mine uses the same technology to detect when and where operational dilution is happening. The system tells where flagging of the different ore bodies has been followed in order to detect which operators pass the excavation limits beyond ore control flagging.

Feb 1, 2020

By Gavin Yuill, Kameron Ray

"The impact on vibration model accuracy by input data that is inaccurate was previously unknown, butthought to introduce significant error. This paper explores the impact of accuracy of different GPSreceivers, bulk truck density fluctuations, and charge weight location convention on the accuracy of the final vibration model output. GPS accuracy is compared between a professional Differential GPS, a “prosumer” GPS unit and a standard consumer GPS chip commonly found in cell phones. Bulk truck density fluctuations are compared from the density given by the operator and the actual cup density measured in the field. Charge weight locations explored are from the bottom of the blast hole, center of the powder column, and collar of the hole. The findings show that the weakest link in vibration model creation is actually low seismograph accuracy standards. Errors introduced from such are generally greater than those introduced from other sources."

Jan 1, 2017

By Catharine L. VanOmmeren

Emulsion quality characteristics such as shelf life, handling, and sensitivity are critical to the end-user. It is therefore important that the consumer be prepared to ask his supplier specific questions. To do so, he needs to have a basic understanding of what an emulsion is and how emulsion properties can affect safety, performance, and environmental impact. The criteria to be covered include: energy, velocity, sensitivity, minimum priming, shelf life, pumpability, effect of AN quality, over-the-road handling, and formulation The consumer will learn how each of these properties can directly affect him. The information will enable him to set minimum standards in product selection, blending, and application.

Jan 1, 1989

By Juan Pablo Henríquez, Sebastian Lozano, Constanza Soto, Gonzalo Segura, Carlos Torres, Danko Morales

The Atacama Kozan underground mine, located in Tierra Amarilla, Atacama, Chile, was facing over-excavation and slow progress in drift construction, issues associated with the use of traditional explosive, ANFO. The presence of water in the blast holes required as well the use of cartridged emulsions, which extended loading times and increased operators’ effort. With loading times ranging around 76 minutes and lower advanced rate, Enaex Underground proposed the use of a pumpable emulsion-type explosive to optimize blasting, enhance safety, and streamline the operational process. This explosive is loading into the blasting holes using an UBT equipment (Unidad Bombeable para Túneles in spanish). This equipment allows mechanized loading, adaptation to small and medium diameter boreholes, ensuring compatibility with varying drilling profiles, integration with Atacama Kozan’s operational equipment and improvement in environmental and occupational conditions, with a measurable reduction in contaminant emissions and worker exposure risks. The implementation of this emulsion-based explosive allows an increase in productivity in drift development. A notable effective advance rate of 95% to 96% was achieved, alongside a reduction in overbreak in 7%, and a decrease in loading time to 40 minutes. Additionally, there was a 40% occurrence of drilling half cast, contributing to contour drift quality. The operation also benefited from a cleaner and safer working environment, enhancing operator ergonomics and reducing the need for jetanol and compressed air.

Jan 26, 2026

By Maja Franjic, Ian Tolliday, Chris Collins, James Wiltshire

Ammonium Nitrate Emulsions (ANE) are a large segment of the explosives market for the mining industry. These emulsions are generally designed to be very stable but when breakdown does occur, removal of the resulting thick, crystallized material can be difficult, hazardous, time consuming and costly. A heavily crystallized emulsion cannot be pumped, so manual removal often becomes necessary. Buildup of semi-solid layers of crystallized emulsion can occur in bulk storage tanks or in truck compartments. In these situations, a manual cleanup involving hazardous confined-space entry and a significant amount of downtime is usually required. Once the crystallized emulsion is removed from the equipment, there is very expensive disposal of the resultant waste via a licensed trade-waste company. A much more desirable solution for dealing with waste emulsion is to completely break the emulsion, allowing the oxidizer and fuel phases to separate into two distinct layers. These layers would then be readily pumpable and could be disposed of much more economically. It may even be possible that the separated oxidizer phase could be repurposed as fertilizer and the fuel phase could be used to manufacture granular ANFO explosives. There are some existing products on the market for breaking emulsion explosives, but these generally need a high degree of mixing into the emulsion to achieve adequate breakdown. The aim of this study was to identify surfactants systems (demulsifiers) capable of effectively breaking a range of waste emulsions with minimized agitation. This paper describes the development and performance testing of novel demulsifier products. The test work involved a comprehensive series of laboratory screening tests, where the demulsifier formulations were optimized. A highly efficient formulation was identified, and field trials were conducted on real world, full-scale waste emulsions. Results will be presented that demonstrate a viable solution for the disposal, and potential re-use, of waste ANE in the explosives industry.

Jan 21, 2025

By Kinross Paracatu, Victor Morais, Luis Marinho, Rolando Fuentes, Lucas Steffen, Leopoldo Muñoz, Washington Vilas

Nowadays, mining operations close to communities face increasingly challenges, especially in their drilling and blasting operations. One of the critical effects are the ground vibrations produced in its surroundings. The impact on the community must be minimized to guarantee the license to operate and, on the other hand, costs must be optimized, and an adequate fragmentation must be achieved to ensure the efficiency of subsequent processes and, consequently, to give sustainability to the business. In this regard, it is necessary that some controlled blasting technique to be performed and the utilization of advanced vibrations models. Currently, it is common in the industry either use of the double decking technique, where very low explosive charges are applied, making it necessary to use smaller drill patterns in order to keep powder factor as per design, which strongly increases the demand for drilling and a consequent impact negative on costs.

Feb 6, 2023

By Thomas M. Keevin, Gregory L. Hempen

A user-friendly model for environmental effects from underwater explosions is presently available. The model by Munday et al. (1986) is effective for determining fish mortality radii from underwater shooting. The IBLAST program (Coastline Environmental Services 1986) from this model includes estimates for both borehole-loaded explosives for demolition or rock removal purposes and midwater shots. Midwater shots may be used for fish population assessments or some seismic surveys. The program produces approximate mortality distances for planning purposes. IBLAST does have serious shortcomings of which users should be aware.

Jan 1, 1995