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By Pavel A. Torres, Darwin Torres, Sandro Huaman

Given the limited efficiency of blast-induced ground vibrations prediction empirical models, due to the complex geological system from a Peruvian mine. An artificial neural network was built in order to get better results. More accurate and precise predictions allowed the generation of blasting domains for future designs and decision making.

Feb 1, 2020

By Tony Francelj, D. Scott Scovira, Remi Proulx

The Meikle Mine is a high-grade, underground gold mine that utilizes a primary and secondary stoping method with delayed backfill. The newly developed Rodeo Mine will start production using similar mining methods in late 2001. The combined production for the mines will be 4100 stpd of ore in 2002. Dilution of the secondary stopes resulting from blast induced overbreak of the backfill placed in the primary stopes was an issue identified as being a major contributor to the total mining cost at the Meikle Mine. To address the overbreak issue, a low-density, polystyrene enhanced bulk emulsion was developed and introduced to the mine. The density and energy of the emulsion was varied until an optimal level was reached. The use of a low-density bulk emulsion has greatly reduced the overbreak of the primary stope backfill when blasting the secondary stopes. Benefits to the mines include reduced secondary stope dilution, lowered total mining cost, and increased revenues.1

Jan 1, 2002

By Tyler Rockley, J. P. Remi Proulx, Ruilin Yang

A highwall blast vibration project was carried out to quantify the level of blast vibrations produced from a trim blast in soft rock and a combined production and trim blast in hard rock. Combining production and trim blasts could be performed without exceeding the mine’s vibration limits.

Feb 1, 2020

By R. Jacob

Mining has been around for a long time, and new deposits are being discovered continually but are becoming more complex for processing and typically sulfide in nature. Most of the large easy deposits with simplified and cheaper to process oxide material have been mined or the deposits are locked up with legal or social issues and may never be mined. It is common to see the mines today being evaluated to mine have little in oxides and have a sulfide component to the deposit. This creates a problem with explosives being selected for the mine because ANFO could cause a reactive ground issue. When evaluating the cost component of mining for future mines, ANFO is the go-to selected bulk explosive because of the cost and effectiveness. More work needs to be done by projects evaluating costs by properly testing the ground and water conditions to match the correct bulk explosive for the ground conditions of the mine. This will prevent a possible safety hazard and the best result for the mine.

Feb 6, 2023

By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan

In the bench blasting, the realisation of an economic, and safe blasting is only possible with a reliable blasting design on condition that considering all sequential activities such as drillingblasting, excavation-loading, haulage, crushing (especially primer crushing). Here what we mean with a good, and reliable design is that ensures an almost displaced, adequately swelled muckpile with desired fragmentation degree for the loaders effectivity, and succesive usage. Meanwhile it must also has no environmental problems such as ground vibration, air blast, and rock flyings, or at least these matters have to be minimised. Two main parameters which have generally being questioned to achieve a safe and economic design on any rock conditions, are specific charge, and burden. In the condition of determining these elements, the other blasting parameters could be calculated according to them, and the blasting design could be completed. Within the scope of this study, it was aimed to determine the optimal blasting conditions of gypsum which is major rock unit of overburden at Sivas Celestine open pit mine. First of all, the engineering (mass, and material) and digging difficulty classifications of gypsum were done according to the current classification systems by using the results of field and laboratory studies. Then the blasting system which was being used on all rock units, was considered, and the necessary data were obtained. After previewing the site properties, predesigns were done, and applied by adopting Langefors design model. The necessary adjustments were done before, during, and after the shots, and the applications were observed. In order to determine, and record the data from each shots properly, a practical form was developed, and all data were transfered to these forms which give information about the blasting results such as muckpile displacement, and height, average particle size, back break, and rock fly existence, number of boulders etc. The blasting parameters such as burden, hole diameter, hole inclination, the amount and position of primers, bench height, delay sequence, and blasting geometry were considered for the iteration of each shots. During the applications, ANFO, gelatine dynamite, and electric delay detonators were used as explosives.

Jan 1, 2004

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 Bonifacio Degay, Mike Lovitt

PT Freeport Indonesia is a block cave mine that now utilizes an advanced undercut method to set up the min in the Deep Ore Zone (DOZ). In this method a slice of rock (undercut) is broken such that it sits on top of the drawbell level. The drawbells are developed to channel the broken ore into the extraction level and to enable the caving orebody to be drawn out in an even and controlled manner. These drawbells are difficult to form due to the small amount of void that can be developed in the low strength rock before firing. Starting with two rises of 2m square, the void ratio for the entire drawbell around 6%, which would normally result in a frozen and unproductive blast. Orica -Mining Services have worked with PT Freeport in a collaborative effort to find a solution to the mining problem. With excellent control of timing of the blasting it is possible to get fluid flow of blasted rock out of the draw points such that more void can be made available for blasting the remaining parts of the drawbell. The i-konTM electronic blasting system gives the exacting control of timing within the blast to achieve this Dynamic Void Generation (DVG). The solution stops the need to charge close to brows in the drawbells and reduces the cost and time related to developing initial blast voidage. This paper identifies the results of the trials including design, photographic evidence and vibration analysis. The flexibility and accurate timing of this electronic blasting system has enabled single hole initiation rather than 4 or more holes being initiated together, thereby reducing the damaging vibrations to the extraction level.

Jan 1, 2004

By Dale S. Preece, Ruilin Yang

Shock wave physics is an important part of air-deck behavior since the bulk explosives in the column impart a shock into the air-deck where the air shock then passes through the air-deck at a rapidly attenuating velocity. Through both high-fidelity modeling and shock physics theory it is shown that the resulting pressure in the air-deck is two orders of magnitude less than the detonation pressure of the explosive. The induced air blast reflects from the bottom of the borehole and this reflected pressure, even though doubled, is still approximately two orders of magnitude less than the detonation pressure. Air-shocks will ring back and forth in the air-deck for a few tens of milliseconds while the adjacent explosive column(s) are detonating. Transmission of the initial shock through the air along with reflections is an intensive energy consuming process. Energy balance results in shock heating of the air and a temperature increase. However, the increased temperature of the air is also orders of magnitude less than that of the explosive detonation products immediately behind the detonation front. Replacing high energy explosives with zero energy air-decks in a blasthole will always have a negative impact on the adjacent rock fragmentation and movement.

Jan 1, 2016

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 Manish Uttarwar, Rajendra Yerpude

India is the third largest producer of coal and the fourth largest in terms of coal reserves in the world. However, new research quite ironically projects that despite the continuing growth in domestic coal production, the country’s exploding economic growth will position it to be the biggest coal importer by 2020. India’s inability to meet the domestic coal demand is mainly attributed to low rate of production, increasing stripping ratio, non use of appropriate technology etc. of coal mining operations here. Presently Indian surface mines which have to shoulder the onerous responsibility of augmenting the coal extraction rate at an even brisker pace are mulling bigger, better and more efficient operations ensuring commensurate rise in stripping work as well. This mammoth task can be accomplished only by deploying smart technologies. In this perspective, cast blasting of overburden emerges on the horizon as a promising alternative for enhancement of the production and productivity of Indian open-pit coal mines.

Jan 1, 2009

By Norman Paley, Finn Ouchterlony

Detailed fragmentation data for different blast delay timing tests at the Red Dog mine in Alaska are analyzed. This work is a continuation of previous work in which the crusher output was found to be better described by the three-parameter Swebrec function than by the Rosin-Rammler function. For a crusher model, the x50 variable sufficed to describe changing crusher input while b and xmax could be considered fixed. For the crusher output from aggregated stockpile rock, as measured by digital image analysis using Split-Online, the constancy of b was not as apparent. In this paper detailed stockpile data, single Split data series, and sieved belt cuts of crusher product are analyzed using the Swebrec and truncated Rosin-Rammler functions. The variability of b is confirmed. By using specific fraction passing sizes a shortcut is presented that removes the need to do curve fitting to determine the three Swebrec function parameters.

Jan 1, 2013

By Jason Wilkinson

Drilling operations are a vital component of surface mining, directly influencing productivity, safety, and cost efficiency. This paper explores a multi-faceted approach to drill optimization, focusing on minimizing delays, and enhancing operational effectiveness. Key areas of inefficiency such as shift changes, fuel and water delays, and time lost between drilling holes are analyzed to identify actionable improvements. Equipment related factors, including the frequency of drill bit and drill steel changes, as well as the condition of deck bushings, are evaluated for their impact on downtime and performance consistency. Additionally, the integration of smooth drives and shock subs is examined for their role in reducing vibration related wear and improving drilling precision. Optimization of pattern approach strategies is highlighted as a means to reduce non-productive movement and align drilling with blast design more effectively. To support continuous improvement and accountability, the implementation of a driller scorecard is proposed. This tool enables the measurement of individual performance based on key operational metrics, fostering a culture of data driven management. Through a combination of field data analysis and best practice recommendations, this study provides a comprehensive framework for enhancing drilling productivity in mining operations. The findings aim to support mine operators in achieving higher efficiency, reducing operational costs, and extending equipment life through targeted optimization strategies.

Jan 26, 2026

By Amos Bryant, Jesse Davis

This paper compares the predictions of the latest Institute of Makers of Explosives Safety Analysis for Risk (IMESAFR) model versus physical test data recovered from ISO-1 and ISO-2 tests in Woomera, SA. ISO-1 testing included placing 1054 kg (2324 lbs) of ANFO (ammonium nitrate-fuel oil) inside an ISO container on a flat bed truck. ISO-2 testing was identical except the NEW was 4000 kg (8818 lbs). The IMESAFR predictions are based on model runs using the best match available to the actual donor type involved in the test. This type of debris analysis is not the standard output of IMESAFR, as the program is designed to assess the probability of human fatality. However, all of the IMESAFR predictions presented were obtained from the use of the actual model equations and algorithms without adjustment. Test results from ISO-1 and ISO-2 will be presented as well as findings from the comparison between model results and actual explosive results from the ISO testing efforts.

Jan 1, 2010

By Jean-Sébastien Lambert, Serge Roberge

"At the end of 2014, Holcim Canada (Demix Aggregates Division) considered the possibility of drillingand blasting a big volume of rock in order to expose a high-quality limestone bench in one of their urbanarea quarries in Laval, Quebec (Canada). The project includes many challenges and has thus been qualified as a high-risk operation."

Jan 1, 2016

By Francisco Sena Leite, Raquel Sobral, Vinicius Gouveia de Miranda, Céu Jesus

"The urgent need for improvements in the control and mitigation of environmental and social conditions associated with the extraction and processing of raw materials is increasingly a demand imposed by legal entities and institutions. Therefore, this present article proposes an improvement of the estimation in the magnitude of the vibrations resulting from rock blasting methodologies in the surrounding areas,incorporating the heterogeneity caused by uncontrollable parameters, such as geological andgeotechnical characteristics. This methodology combines the use of empirical vibration attenuation lawscommonly known and with terrain discretization techniques using Voronoi’s decomposition. For thevalidation assessment of this methodology, the data set collected and compiled is composed by 87 vibration measures collected in 16 sample points in one area of study of which 2/3 of the samples were used to create the model and 1/3 for the validation. Using normality tests for statistical residue analysis,it is possible to infer that this present model has null residual mean, as well as a smaller sum of residualerrors. Comparing the methodology present in this paper with the procedures executed nowadays, areduction of the errors associated with the estimation is obvious, highlighting a better characterization of the behavior of the vibrations associated with rock blasting."

Jan 1, 2017

By Shazad Hosein, Rob Farnfield, Bill Birch, Liam Bermingham

The propagation of a shock wave through air as a result of quarry blasting consists only of one type of wave, the compression wave. This is in marked contrast to seismic waves where a number of different types of wave are generated by the one blasting event. Even so the interaction of the burn time of a single hole and the resulting air overpressure is still too complicated to be able to be accurately modelled from first principles. It is considered that the best way forward is to monitor an individual single hole to obtain a signature wave form that has resulted from this complex interaction. Once this wave form is known, the variation in geometry of a mutli-hole blast and the timings of the successive detonations can be modelled to give a sufficient degree of accuracy to recreate the likely magnitude, duration and wave form of a multi-hole quarry type blast. This can then be directly compared with actual air overpressure wave forms from quarry blast to verify the model.

Jan 1, 2012

By Benjamín Cebrián, David Flores, María Rocha Gil

This document shows the evolution of drilling and blast digitization process, savings and trends in a mine, using new technologies that creates business opportunities and general improvement of D&B process.

Feb 1, 2020

By Mick Lownds, Ruilin Yang

The potential advantages of electronic detonators with accurate timing have been increasingly recognized by the blasting community. However, in comparative blasts the results with pyrotechnic timing are sometimes comparable to those from electronic timing. Statistical variation in blast results is a plausible cause of these observations.

Jan 1, 2011

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 O Omidi

Selection of delay times to optimize fragmentation has been a controversial topic among researchers and blasting practitioners. This paper reviews previous experimental information and presents the results of new tests conducted in small blocks constructed using a commercial grout. The effect of the delay on the average fragment size, coarse fragmentation and uniformity of fragmentation is discussed. Fragmentation was coarser at extremely short or extremely long delays, while a fairly constant average size was obtained at a variety of intermediate delays. Uniformity, defined as the slope of the fragmentation distribution through the average fragment size, was poor at short and very long delays and relatively constant at the intermediate delays. Some tests attempted to minimize the effect of gas penetration by lining the boreholes with copper tubes. When this was the case average fragmentation changed marginally, while uniformity was significantly affected by delay and was typically smaller than in the unlined tests.

Jan 1, 2014