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By C. Zuniga, S. Combrinck, C. Peters

Agnico Eagle Gold have partnered with Enaex Australia at their Fosterville gold mine to leverage a combination of drill and blast technologies to optimise underground development mining. The mine is the first site globally to collaboratively develop and trial Enaex SWIFT electronic development detonators, which utilise a novel approach to the user interface, simplifying implementation and enabling the benefits of electronic initiation without the complexity of a conventional system. This has been combined with the use of a Sandvik 422i smart jumbo, and the Enaex underground emulsion charging unit with the capability to tailor the delivery of explosives as required and report on a hole-by-hole basis. The combination of these technologies enables full engineering oversight of the development cycle, in turn enabling optimisation of this process in a historically conservative application. The methodology for leveraging these technologies is to bore a controlled and defined blast pattern through using a smart jumbo, load the blast holes utilising lace loading to deliver a desired quantity of ammonium nitrate emulsion per hole, with the ability to reduce chargeweight for perimeter control, and utilising Enaex SWIFT electronic detonators with flexible template type pre-defined delays to initiate the blast holes. Subsequent to firing and excavation the performance of the blast in fragmentation, advance efficiency, and overbreak and underbreak is measured and reviewed. This is then used to optimise the development cycle and apply to other parts of the mine.

Feb 6, 2023

By A. Ribeiro

The effective utilization of resources and process optimization play a crucial role in the sustaining and growth of overall businesses. This principle holds true in the mining sector, where particular attention is required during the comminution steps. This necessity arises from the fact that mining operations often consume substantial amounts of energy in mineral processing. Therefore, it becomes imperative to thoroughly study the integration of comminution steps. In many instances, an approach to be studied is the operation commencing with the drill and blast phase and culminating in the grinding product process. Nevertheless, establishing an optimal integration between drill and blast operations and the grinding phase is a complex undertaking due to the direct influence of rock characteristics on this process. And in many cases, the complexity and variability of such physical characteristics makes mining operations to ignore such influence. Consequently, Enaex Mining Technical Solutions (EMTS), in collaboration with Lundin Mining's Chapada Mine engineering team, and with the assistance of Hatch Consulting and Technology, has undertaken a comprehensive study aimed at enhancing mill throughput at the Chapada operation. The basis of this study lies in characterizing the rock masses present in the Chapada Mine to gain a deep understanding of the material that needs to be comminuted. Subsequently, the mineral processing team determined the most suitable size distribution for the Run-of-Mine (ROM) material. With this information, the drilling and blasting team built a site-specific blast fragmentation model, able to simulate various blast design scenarios. This approach enabled to optimize the utilization of available drilling and blasting resources while striving to achieve the optimum ROM characteristics. Since 2021, the Mine to Mill methodology has been progressively implemented at the Chapada Mine. As a result, the blasting engineering team now utilizes the blast plans generated by the fragmentation model simulations as a foundation for designing blast plans that align with the operational and financial capacities of the mine. Overall, it was predicted that this implementation could lead to an average increase in mill throughput of 13-22 % depending on blend feed, once all recommendations are implemented. Even with partial implementation, plant results demonstrate a 5 % increase compared to the period before the Mineto-Mill project, without any coarsening of the associated grinding product size.

Jan 1, 2024

By A. S. Tawadrous

Fines are produced in any blasting application. Depending on the application, fines may or may not be a desirable product of the blast. In most quarry and construction applications, fines are considered an undesirable product since it does not constitute a sellable product and there are costs to the operation for disposal. On the other hand, in most open pits fines do not represent as much of a problem since the ore has to be crushed and ground after being blasted. Therefore, fines in such operations may reduce the energy consumed in the downstream operations.

Jan 1, 2012

By J. Silva, T. Worsey

The Worsey-Silva equation determines the optimal row timing for the smallest fragmentation and allows fragmentation models to be adjusted due to row timing. The equation utilizes the concept of dynamic confinement to determine when the best time to fire the next row or sequence series would be if the smallest fragmentation is desired. Full-scale testing was conducted at an aggregate quarry in Ontario to support the theory and equation. The full-scale testing comprised six (6) blasts, two (2) different contractors, and three (3) different sequences. The test parameters were kept consistent, besides changing the timing between sequential charges to explore the timing sequence’s influences on fragmentation. From this research, the theory of dynamic confinement relating to row timing was discovered, and the equation to determine the optimal timing for the smallest fragmentation was derived. An equation to adjust fragmentation based on row timing was derived from the full-scale testing and literature review. The Worsey-Silva equation can be used with other fragmentation models as it takes the fragmentation results from the other models and adjusts them based on the row timing used. The paper explains the theory behind the equation, the research supporting the findings, and the developed Worsey-Silva equation for row timing

Jan 1, 2024

By Syed Haq, Kyle Optt, David Campo, Doug Anderson

Limitations on allowable levels of vibration from construction activities generally consider either annoyance or damage. While activities such as drilling and roller compaction primarily create annoyance, the major concern for blasting is usually damage. Many years of research have developed correlations between peak particle velocity and either threshold or structural damage. We emphasize the term “correlation” for two reasons. First, peak particle velocity is only a single-valued representation of a vibration waveform, and does not characterize it completely. Second, a given peak particle velocity by itself, even a particle velocity waveform, will not damage anything – strain does. Why not measure strain all the time? Strain is very localized, and can vary substantially over short distances, so choosing the appropriate strain measurement can be difficult. Measurement of strain is appropriate when either the behavior of a specific structural element is needed, or the overall response of a structure can be adequately represented by a well-selected strain measurement. We will discuss the appropriateness of both particle velocity and strain as deformation and damage descriptors, in general. We will also describe a specific case history, from a tunnel project in New Jersey, correlating strain with peak particle velocity. Finally, we will make recommendations for the choice of measurement type for some common situations.

Jan 1, 2004

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 E. Contestabile, B. von Rosen

Recently, the Canadian Explosives Research Laboratory (CERL) completed its investigation of a truck accident, which involved 18,000 kg of commercial explosives, 13,000 kg of which was ANFO. Over the three years of the investigation unconfined burns of piles of ANFO were performed. In its final phase of the investigation, two burn trials were performed in an attempt to recreate the accident and the ensuing fire, to identify probable mechanisms that led from burning to detonation. Two full-scale tests were performed using complete tractor-trailers. In each test, the trucks were placed in a jack-knifed position with the majority of the explosives located on the ground in front of the trailer. The explosives were placed in a manner to provide maximum confinement and to maximize the possibility of explosion/detonation while remaining as faithful as possible to the perceived accident geometry. The tests were instrumented using thermocouples and video cameras and observations were made on the burning characteristics of the explosives, tractor-trailer and tractor-trailer components. In each test the explosives burned calmly for approximately 80 minutes. There was no evidence of explosion or of unstable burning. The heat caused several truck components to rupture violently. These included the tires, some engine components, the spring brake chambers and possibly the fuel tanks. Of these, the most violent were the truck tires. Although no quantitative data was gathered on rupture violence or fragment velocity, it is speculated that several truck components might produce fragments with sufficient energy to initiate heat-sensitised explosives under favourable circumstances.

Jan 1, 2004

By Mark William Withey

Blasting safety in surface mining is a necessary industrial goal. Proper techniques and disciplines exercised during the blasting process enhance the probability of achieving that goal.

Jan 1, 1995

By Jim Mikelait

?? Why do we need security? ?? Needs assessment ?? Elements to any security system ?? Protect, Detect, Alert, Response ?? Electronic Security System Criteria ?? Advantages and Limitations of Various Security Options ?? Internal measures to protect against potentially harmful employees ?? How can technology improve my business?

Jan 1, 2006

By Eduardo Gonzalez Fernandez, Jaime Rios Vazquez

This report substantiates the connection that always exists between explosives and vibrations and draws attention to low frequency vibrations, which are the moat dangerous for the structures affected.

Jan 1, 1986

By Stuart Pether, Cedric Goode

The Mt Morgans Minesite is located 800km North East of Perth, the Capital City of Western Australia. The surrounding region has been a significant producer of gold since the turn of the century. The mine was previously host to a township of approx 40 - 50,000 people.

Jan 1, 1996

By Joe Dannenberg

A word of preface: The material contained in this talk is not completely original. Many thoughts and actual words come from a fine little book called "1,000 Years of Explosives" by William S. Dutton. The book is now out of print, but if there is enough interest shown by this Society, perhaps we can have it reprinted.

Jan 1, 1980

By John R. Jr Tripi, Paul N. Worsey

Split round blasting is commonly practiced in underground uranium mining in the Big Indian ore belt located in Southeast Utah. The technique is used to prevent ore dilution by separately blasting the ore from the face.

Jan 1, 1985

By A N: Zditovetsky Shishov, M G. Menzhulin

At present in a building industry demand for products from granite, gabbro and other rocks, steady to erosion, natural and chemical weathering, was essentially increased. It has caused the enlargement of exploitation of stone block deposits and necessity of creation of new technologies of hard stone cut.

Jan 1, 1996

By Andrew Stirling

Quarry operators are under constant scrutiny by individual neighbors and neighborhood associations due to the environmental issues arising from daily quarry operations. Issues range from truck traffic, to dust, to blasting induced vibration and noise. Quarry operators and shot service providers employ best practices to minimize disturbances to neighbors. However, these efforts have been limited by the accuracy and flexibility of conventional initiating systems and design techniques.

Jan 1, 2002

By P D. Katsabanis

Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction includes sympathetic detonation and desensitization of explosive charges as well as the modification of firing times of conventional pyrotechnic detonators.

Jan 1, 1995

By Monica Stuckert

Field studies were made at an Appalachia coal stripping operation to evaluate the differences in cost and performance between blast casting with pre-split dewatering versus conventional coal overburden blasting.

Jan 1, 1985

By T N. Hagan

Where explosion energy moves rock from the in-situ to its desired location without considerable assistance from digging and/or hauling equipment, good fragmentation is of minor importance. Maximum displacement must remain uppermost in the mind of the blast design engineer.

Jan 1, 1979

By Beau Bryson, Tony Cooley

The following paper is a technical discussion depicting the type of blasting procedures used to control vibration levels. The blast vibration control criteria that was established and the type of monitoring program that was used. Also, the importance of good communication with the concerned neighbors.

Jan 1, 1985

By Geff Gordon, Dale Nies

Small diameter borehole blasting can be very efficient and cost effective. As residential development continues to expand, many areas are now requiring blasting for site preparation and upgrading old utility systems or constructing new ones.

Jan 1, 1990