Search Documents

By Manuel Gutkrrez, Nasslo Gallardo, Arturo Cancec

The study done in Dofia In&s de Collahuasi aims to improve the fragmentation in one of the most difficult rocks to deal with in an operation, It is the Ignimbrita. In order to avoid ejections and to increase the efficiency of the explosive it has been obtained an improvement in the stemming quality by using the Blasting Optimisation Program in Ignimbrita. Different materials were used in the stemming. In 1997 it was used soil material (Paleorrelleno), then in 1999 started the use of crushed gravel and during this year it is being implemented the utilisation of Stemtite only loaded with drill cutting. The first improvement was obtained with the utilisation of gravel, yielding good fragmentation results in comparison with the stemming with detritus material. The stemtite has made easier the blasting operation and it has signiticantly improved the fragmentation.

Jan 1, 2001

By Nikolaos Petropoulos, Ulf Nyberg, Daniel Johansson

A series of signature boreholes were blasted to observe any difference between confined and free face blasts. Four geophones were used to capture the compressive wave. The conventional approach, i.e. the calculation of vectorized peak particle velocity (vPPV) did not show any difference. Also a wavelet transform was tested.

Feb 1, 2020

By Carlos Alvarado, Hernan Narea, Jhon Silva, Bryan Townsend, Katherine Gil, Brayan Caceres, Felipe Pontanilla

With the promising development of new technologies, automation in Drill and Blasting (D&B) is on the horizon. The data generated in all D&B activities, which is currently segregated, can be linked to become information and carry a logical meaning. This information can be used to identify critical activities and make decisions regarding corrective measures to accomplish the goals of D&B. Minera Caserones, supporting Alert2Gain (A2G), and Dyno Nobel, has been working on the development of a quality assurance and quality control (QAQC), system for the mine involving all D&B activities. The main variables in the model for D&B include data from the geology of the deposit, drilling, explosive products, and material loading, among others. To create the model, the mine is divided into blasting polygons. Those polygons are part of a block model. The block model is assembled following different rules, such as: • Block sizes of 4m x 4m x 15m, • Classification of the blocks to a particular blasting polygon using a geospatial intersection algorithm, • Algorithms connect all the pieces of data automatically with the minimum of human intervention and populate the block model, Because measuring data for each block is impossible, another set of rules and algorithms completes the model. Dyno Nobel generates an essential set of data for the QAQC system. Explosive truck loading rates and explosive products, among other data, are also included in the system. The system autogenerates reports every hour, and a summary of the results of each mining day (a mining shift of 12 hours) is distributed by email to all responsible persons to identify the critical tasks and then to make the proper adjustments to accomplish the goals of D&B. The information is updated every hour and available through a dashboard for easy and straightforward interpretation. This paper explains the conceptual details of the QAQC system implemented in Minera Caserones, how the data is aggregated automatically from the different sources, shows examples of the type of information in the dashboard, and presents a successful case where a deviation was detected, and the corrective measures that were implemented to keep the performance of the D&B activity. The paper finally discusses the next steps toward an autonomous D&B system based on new AI technologies, with minimum human intervention.

Jan 21, 2025

By C. E. Johnson, R. L. Bauer, E. M. Johnson

In industry, the strength of a blasting cap is often equated to the type of explosive it can detonate. Comparable cap strength is becoming less important as nearly all caps manufactured today can initiate high explosives, such as primasheet, with ease. Previous studies were conducted to assess the quantity of energy released by various detonators into the directional propulsion of the detonator’s casing. However, the question of how much of this propulsion energy is needed to initiate an explosive remains unanswered. This study will assess the fragmentation size and velocity needed to initiate a high explosive when they are not in direct contact. For this study, primasheet was used as the main charge as it is relatively insensitive and can be situated in different positions relative to the detonator. Electric, non-electric and electronic detonators were used to evaluate initiation potential. The primasheet is observed in response to being in contact with a detonator, and not in contact with the detonator at various distances and angles. This allowed the quantity of energy transferred into the primasheet to be observed and for the initiation of the sheet to be recorded using high-speed video. This study will report the energy necessary to initiate the primasheet at various distances and angles from the charge from a number of widely used, commercial, hot wire blasting caps.

Feb 6, 2023

By Braden Lusk

Vibrations as a result of blasting practices in mining engineering are a complex phenomenon controlled by many variables. Mine blast vibration modeling and prediction is becoming more important as a consequence of the general negative perception of mining activity by the public. Many communities (all over the world) close to mining activity often complain about airblast and vibrations produced from blasting activity. It is important for the mining industry to have tools and understandable methodologies to model and predict blast vibration. These tools can then be used to control vibration at neighboring structures.

Jan 1, 2013

By Goran Lande, Bernt Larsson, Dennis Clark

The effects of vibrations on close surroundings has been studied in Europe and the United States extensively in the past three to four years due to the ever increasing demands of environmental control. Therefore, "routine measurements" or "standard vibration consulting services" are being carried out by numerous firms with widely different qualifications.

Jan 1, 1983

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 Jeremiah Cohn, Rachel L. Bauer, Catherine E. Johnson

Water is frequently used in explosive applications to increase explosive performance and reduce air overpressure. Water tamping can enhance cutting abilities of shaped charges in demolition and increase impulse of kicking or breaching charges. In explosive disposal, water is used to suppress air overpressure and reduce noise. Despite its widespread use, the specific effect of water placement, whether in front of or behind the explosive, has not been studied. This work evaluates the directional effects of water placement on blast performance using 400-gram sheet explosive charges in five configurations: no water (control), rear-only water (tamped), front-only water (pushed), water on both sides (confined), and a thin front-and-rear water layer (low mass confined) to assess reduced mass effects. Water was sealed in plastic bags and held in position with custom 3D-printed cages to ensure consistent geometry and contact. A modified ballistic pendulum consisting of a hanging steel W-beam was used to evaluate impulse transfer, with high-speed video capturing swing velocity. Air overpressure was recorded using a seismograph microphone. Rear-only water (tamping) increased beam swing velocity by 69% over the control while confinement with water on both sides increased performance by 12% at a 2:1 water-to-explosive ratio and by 50% at 4:1, though it still underperformed the tamped-only configuration. Pushed water alone did not increase beam momentum and reduced tamping effectiveness by 19% when combined. Seismograph microphone data showed that pushed and low mass confined water configurations produced some of the highest air overpressure levels (up to 139.2 dB), while tamped and control charges produced lower levels (~134–136 dB), suggesting that pushed water may amplify, rather than mitigate, air shock transmission. These findings show that water placement has a strong directional influence on blast dynamics: water behind a charge enhances energy transfer to the target, while water in front provides limited or potentially counterproductive mitigation. This study advances understanding of water–explosive interactions and will lead to more effective charge designs for breaching, disposal, and demolition.

Jan 26, 2026

By Jaime Herrero, Santiago Gómez, Pablo Segarra, José Ángel Sanchidrián

This paper presents a mathematical model for the study of the 2D movement of blast bench faces based on the high-speed video analysis of three blasts at El Aljibe quarry (Spain) recorded at 2,000 frames per second. In these blasts, a set of bags of 0.75 × 0.75 m were placed in front of a selected blasthole defining a reference plane in which to study the kinematics of the movement. The burdens range from 3.86 m to 5.54 m, with a bench height of 12–13 m. An affine transformation system was calculated to convert coordinates from the video images into actual spatial coordinates. The problem is established from a multi-objective minimization approach in order to simultaneously optimize two defined objectives: trajectory fitting using Total Least Squares regression, and time–displacement regression using Ordinary Least Squares. Muti-objective minimization formulation produces Pareto plots of non-dominated solutions, i.e., optimal combinations of initial velocities and response times, (i.e. time between detonation and the onset of bench face motion). From the Pareto frontier, the most balanced solution is selected. Blast response time lasts only a few milliseconds and appears so brief at the frame rate used that it is difficult to detect visually. In this context, the bi-objective optimization-based approach proves to be a more robust tool than frame-by frame survey for quantifying such a rapid event while also maintaining a strong performance in the trajectory fitting task. Root Mean Square Error (RMSE) for the two minimizations average 0.22 m and 0.13 m, respectively. The initial velocities obtained range from 4 to 17 m/s, and the response times 0.7 ms to 21.7 ms. An analytical model is also presented for predicting fragments initial velocity and response time as functions of blast geometry and rock mass properties, explaining approximately 87% of the total variability.

Jan 26, 2026

By H P. Rossmanith

This contribution addresses the advanced blasting technology which is based on wave propagation theory and fracture mechanics. The new concept of sonicity and the principle of maximizing sonicity in blasting as well as the energy or work of a blast operation will be introduced. It is shown that - in contrast to common belief – it is not the velocity of detonation which controls the blast but the relationship between velocity of detonation and the wave speeds, in other words, the Mach numbers of the blast operation. Based on numerous practical blasts in Germany, the authors show that, when using wave dynamic concepts, there is a linear relationship between peak particle velocity and the work of a blast operation and this linear relationship is controlled by the sonicity of the blast. Extensions to layered and faulted rock masses are presented. It will become clear that a second change of paradigm is enforced, the first one being the implementation of short time delaying. Again, the acquisition of knowledge in wave progation theory and fracture mechanics becomes mandatory in advanced blasting technology, where the art of blasting is now fully transformed into a science of blasting with little room for methods of trial and error.

Jan 1, 2010

By J. Silva, M. Kotraba, F. Pontanilla

Blasting is the application of highly complex science that, in some cases, could be viewed as an art. Many variables are involved in a blast, including geology, pattern design, timing and firing sequence, and explosives selection. Assuming that better results can be achieved by only increasing the powder factor is inaccurate. The Drill-to-Mill (D2M) concept has been in the mining industry for over two decades. The D2M approach is commonly viewed in an oversimplified manner, assuming that by simply increasing drilling and the amount of explosives used (both of which add operational costs), the downstream value will be created. An optimized D2M initiative should combine the smart application of explosives at the beginning of the mining process, matching the dynamic properties of the rock to the explosive selected to improve the efficiency of the energy created by the explosive to the rock mass being blasted, and to bring benefits to the mining operation across the entire mining and processing value-chain. This paper reviews the principles behind matching the shock impedance of the rock and the explosive and compares the traditional use of explosives versus the smart application for two hypothetical blasts.

Jan 1, 2024

By John Wall

The use of electronic detonators in civil tunnelling applications, to reduce vibration is small firings has been successfully utilised for a number of years. As part of the mining industry’s commitment to reducing blast damage during the development cycle in underground mining applications, a series of development blasts using eDevTM electronic detonators in typical mining applications was conducted in North Queensland, Australia.

Jan 1, 2012

By Jonathan Heiner

Rio Tinto Bingham Canyon Mine started its South Wall Push Back (SPB) in 2011. This push back will mine through the only road to the pit bottom (the 10%). The pit bottom is the main ore sector for the mine and supplies about 80 to 90% of the ore. In late 2017 the mine set off a blast in SPB that created a small wedge failure on the high wall between SPB and the 10%. This wedge failure released a rock approximately 20 minutes after that blast that rolled down the wall landing on the 10% near and then contacting a light vehicle

Jan 1, 2019

By Tyler Rockley, Cara Rosen

Blasting at a granite quarry in eastern Maryland produces elevated air blast readings that can fall into the cautionary zone for the state of Maryland environmental regulations on a semi-regular basis. When designing blast patterns in this quarry, challenging geology creates rough and uneven blast faces that can be difficult to capture with 2D laser profiling fully. Utilizing several methods known to manage high air blast results like pattern adjustments, decking, and timing changes have not achieved consistent outcomes. Accurately capturing and modeling this geology is the key to controlling high air blast. 3D modeling and profiling by drone is the solution to understanding accurate face profiles and real minimum burdens. Using 18 months of blasting data and air blast results to establish a baseline, the comparisons between blasts designed with 2D profiling and blasts designed with drone 3D profiling show improvement in air blast levels. Additionally, shots with completed drilling were drone profiled to understand precise amounts of burden for each borehole. This 'audit' of a blast allows for custom loading of explosives, accommodating the amount of burden present on the blast face. 3Dprofiling is not a new tool in the blasting industry, but a drone alleviates some of the restrictions ground systems face. Controlling and managing air blast, as it pertains to face burdens, requires an understanding of those burdens from all angles. A drone provides that distinct level of insight. The results of this study indicate that drone profiling is managing the customer's air blast readings, allowing the customer to maintain their license to operate within the community.

By PHILIPP HARTLIEB, Peter Schimek, Thomas Seidl, Pablo Segarra, José A. Sanchidrián, Juan Navarro

This paper develops a new Blastability Index to assess hole-to-hole fragmentation in bench blasting based on a new Rock Factor exclusively obtained from drill-monitoring data, that can provide an automatic assessment of rock structure, strength, and waste/ore, the effective energy factor of the explosive and the delay time per blasthole.

Feb 1, 2020

By Alyse Munro Hindley

The increasing negative public opinion toward blasting has led to stricter regulations and increased costs. This paper outlines alternative methods of rock excavation and the safety regulations and certification required by blasting professionals. Most importantly, however, it showcases the benefits and accomplishments that controlled blasting bring to society, giving the public a better understanding of the necessity of blasting in modern society.

Jan 1, 2015

By Tyler Rockley, Cara Rosen

Blasting at a granite quarry in eastern Maryland produces elevated air blast readings that can fall into the cautionary zone for the state of Maryland environmental regulations on a semi-regular basis. When designing blast patterns in this quarry, challenging geology creates rough and uneven blast faces that can be difficult to capture with 2D laser profiling fully. Utilizing several methods known to manage high air blast results like pattern adjustments, decking, and timing changes have not achieved consistent outcomes.

Feb 1, 2020

By Randall Wheeler

In early 2008 we were asked by a quarry to become involved in a conflict with a pipeline company concerning blasting near one of their underground high pressure gas lines. The pipeline company, without the quarry’s knowledge, had sought and obtained a temporary restraining order against the quarry forbidding them from blasting near the pipeline.

Jan 1, 2011

By Philemon Desrochers, Ken Qian Liu

Following the success of the West Ore Zone distress mass blast in 2001 at Brunswick Mine, a similar approach was taken to distress the North Regional Pillar (NRP) which contained over 3 million tonnes of high grade ore. The NRP is located on the 1000 m Level with very poor hanging-wall (H/W) rock mass qualities. After an extensive geotechnical review, the distress slot is located close to the foot-wall (F/W) of the NRP in order to have the competent ore as H/W. The longitudinal area to distress covers 115 m along the strike and 85 m high from 1000 1-sub to 850 Sill. Prior to the final mass blast, 3 voids were created to allow rock swelling: the North void, the South void and the trench just below the mass blast. After over one year of preparation, the mass blast of 202,000 tonnes was successfully initiated on February 7, 2003 with 1561 electronic detonators and 210,000 kg of emulsion explosives. The blast achieved its objective of distressing the NRP as indicated the mine-wide micro-seismic monitoring system. This paper describes different stages of the project from void preparation to the mass blast itself, as well as some detailed aspects such as muck-pile prediction for mucking sequence with the help of DMC_Blast simulation code and electronic detonators.

Jan 1, 2004

By Thierry Bernard

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts

Feb 1, 2020