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By K. M. Kim, J. B. Kemeny

A case study was conducted with 5 shots with varying pre-blast block sizes and explosive energies. From this case study a site-specific predictive fragmentation model was developed. There are two main innovations in this study. One is using an image analysis program (Split-Desktop 3.0) on the bench face to obtain the pre-blast block size (F80) quickly and consistently. Another innovation is to utilize the Schmidt Hammer Hardness (SHH) to estimate intact rock strength.

Jan 1, 2011

By Hector O. Romero, Paulo C. Fernández A, Christian Rees Prado, Claudio C. Gajardo

In open-pit mining operations, the presence of remnants from past underground labors represents a significant operational challenge, especially if they are in the surroundings of high-grade zones. The existence of uncrushable elements, such as metallic support fragments of abandoned equipment, can trigger critical operational issues if they reach conveyor belts systems or primary crushers, jeopardizing the mine to plant operational continuity. These kinds of incidents lead to expensive unplanned shutdowns, the increasing of corrective maintenance events costs, and risk to meeting expected production results. This work demonstrates the application of a three-dimensional numerical modeling tool for simulating rock displacement post-blasting (by integrating key design parameters, such as blast pattern design, detonating times, charge distribution and pre and post blast surveying). The study was conducted at Andina Mine, operated by Codelco, Chile, and enabled the identification and zoning of areas with potential presence of underground hazards in displaced rock mass, using historical data from previous workings and geotechnical mapping. The displacement results were compared to the actual post-blast surveying, ensuring an acceptability level above 80%, considering both fully confined (bank opening) and free-face blasts. Additionally, this approach allows the determination of an optimal safety offset, initially set at 10 meters and currently under validation for potential reduction. The results supported the determination of safe extraction zones and the design of excavation, loading, and haulage strategies from mine to plant or stockpile, ensuring 100% reliability in the segregation of high risk materials. Implementing displacement simulations underscores their relevance in operational risk prevention and mitigation, adding value to short-term mine planning and strengthening the safety, efficiency and profitability of the open-pit mining production process.

Jan 26, 2026

Electronic detonators are receiving increasing acceptance in the blasting industry. Electronic detonators offer several distinctive features over electric and non-el (shock tube) detonators including better timing accuracy resulting in excellent fragmentation and vibration control, field programmability and digital safety means. Several electronic detonator systems are available commercially today serving the surface, underground and seismic needs.

Jan 1, 2010

By Ron Stewart, Richard Youmaran, Andy Adler

In the current context of heightened concerns with explosives security, there is significant interest in technological controls to improve security. It is important to be able to control what is fired, by whom, where and when. This paper describes research Orica has performed to investigate and test biometric systems to address the question of "by whom". The goal of this research is to incorporate the most suitable biometric system onto the 'blaster' unit of an electronic initiation system. This approach will ensure that only authorized personnel can initiate a blast involving electronic detonators. Requirements analysis: we initially explored many different biometric technologies to evaluate them against the requirements, including security, usability, ruggedness, size, form factor, privacy, and operational temperature range, This analysis identified chip based fingerprint sensors as the best candidate. Development of prototype units: in order to test the identified sensors, we modified standard, commercially-available, electronic blast initiation units ("blaster") to incorporate a fingerprint reader. Testing and evaluation: Biometric We conducted a biometric scenario evaluation in order to determine: 1) security level (measured by false accept rate (FAR)); 2) usability (measured by failure to enroll (FTE) and false reject rates (FRR)), and to 3) discover environment specific issues and challenges (such as temperature, humidity, dirt, or those related to the usage patterns of the user group). Tests were conducted at quarry sites in eastern Ontario, Canada. Results show rates of: FAR= 0%, FTE= 1.67%, FRR= 28.81%. Overall, these results suggest that this fingerprint biometric technology has a good level of usability in this application of electronic blast initiation control.

Jan 1, 2007

By Brian Sandhuas, Robert McClure

All flyrock incidents have the potential to result in injuries or fatalities that can result in loss of company reputation, license to operate with clients, and bear the exposure to high cost liability. From 2007 to 2009, one North American Quarry and Construction Business experienced a series of flyrock incidents. In the spring of 2009, this business declared that the frequency and severity of Flyrock Incidents had reached an unacceptable level. A Flyrock Elimination Program was launched.

Jan 1, 2012

By B. Winterberg, C. Lewis, M. Starkel, C. Johnson

Non-electric systems, specifically shock tube, have become the pyrotechnic detonator of choice over electric due to their safety regarding accidental initiation from stray radio signals. Typically, the best practice when hooking up shock tube systems is to have direct contact to ensure initiation. When gaps are introduced to the explosives chain, there is potential for detonation to come to a halt. It is understood that direct coupling is required between the various elements in the explosive chain to ensure detonation. This holds true whether tying in non-electric detonators, loading holes in a mining related blast, or priming a block of C-4. Poor contact and gaps in the explosives chain can lead to detonators firing out sequence, leading to increased vibration, air overpressure, and other undesirable blast results. Furthering work conducted in previous experimentation, a new study was conducted at the Missouri University of Science and Technology’s Experimental Mine in Rolla, Missouri to observe the initiation potential of an air gap and fragmentation on non-electric shock tube. A series of small test blasts were conducted using 50 grain detonating cord and fragments from a blasting cap to initiate a non-electric shock tube across an air gap of varying distances. The data collected in the high-speed imagery was used to analyze the velocity of the pressure fronts and blasting cap fragments used to initiate non-electric shock tubes across an air gap. It was found that the shock tube was sensitive to 50 grain det cord at a 5cm (1.97in) distance while parallel and 10cm (3.94in) when perpendicular as well as sensitive to frag from the electric cap out to 2.4m (7.87ft).

Jan 1, 2024

By Stephen Mansfield

In metalliferous mining operations, subdrill is that portion of the blast hole that is drilled below the target grade elevation, and in most cases loaded with explosives. Its primary aim is to enable efficient excavation down to the target floor level. Subdrill is often described as being expensive and that excessive subdrill should be avoided, as it can result in damage to the subsequent floor, lead to difficult drilling conditions and higher vibration levels. As a result, many operations aim to apply the bare minimum amount of subdrill in order to excavate to the target floor

Feb 1, 2020

By Mark Spaniel

Computer 3D modeling to evaluate the potential underground blasting fragmentation performance based on rock within calculated damage radii along drillholes, as well as the burden distance from explosives along each drillhole. The results estimated from the 3D computer models closely predicted results found in the real world testing.

Feb 1, 2020

By Randall M. Wheeler

Many blasting companies are using simulated production ground vibration waveforms to aid them in the control of their vibration effects. The simulations are typically produced by using a seismograph to record a signature waveform from a single hole shot and subsequently applying the various delays to be used in a proposed production design. The ability of this simulation method to give good results usually depends on three primary factors. These are: 1) the homogeneity of the seismic travel path from hole to hole; 2) the consistency of the seismic energy release per unit of explosive from hole to hole; and 3) whether or not the delays fire as planned.

Jan 1, 1991

By J. Sigler

A series of small scale tests have been performed to establish the effect of powder factor and initiation timing on the grindability of rocks. The blasts were performed in high quality granite blocks, which were cut from stone prepared by dimensional stone quarry operations. Three different types of granite were tested. The charge configurations included detonating cord placed in five holes with water as a coupling medium or concentrated charges of equal mass, placed in the same number of holes, fully stemmed or air decked. The powder factor was varied from 0.4 to 1.2 kg/m3. Typically all charges were detonated simultaneously; however, in some experiments, detonation waves collided in the middle of each borehole and in others a small delay was used between charges. All fragments were collected and screened, and drop weight impact tests were performed on selected size fractions, using different impact energy, to calculate the resistance of the rock to impact breakage. The work index of some of the blasted samples was measured using a standard Bond mill arrangement. The experiments generally showed increased softening of the rock with powder factor, which appeared to be the dominant factor. Charge configuration as well as in-hole collisions of detonation waves affected the initial fragmentation but had little effect on the impact breakage of the samples.

Jan 1, 2008

By Gary Anderson, J. P. Remi Proulx

Rio Tinto’s Colowyo Coal Mine produces 2.1 million tons per year in northwest Colorado. Colowyo uses the terrace mining method to recover up to seven coal seams ranging in thickness from 5 to 20 feet. Coal recovery in the 6 foot thick high grade C-seam has recently been challenged due to large variations in the pitch and roll of the seam. As well, some coal damage was seen due to an increased thickness of the overburden consisting of a hard sandstone channel.

Jan 1, 2012

By Daniel B. Conn, John L. Floyd

PhotoSeis™ is a blast analysis method that combines the advanced technologies of high speed motion picture photography and digital seismology. When fracturing rock with the use of explosive energy, the human eye cannot detect the details of the process due to its short duration. An extended time base is required to accurately quantify the response of the rock mass to the detonation process. This time base is provided by the use of high speed motion picture cameras. The control of ground vibrations and airblast is an important consideration when developing efficient blast designs. High vibration and airblast levels can be an indication of improper design, inaccurate detonators, or adverse geology. Since many factors can elevate airblast and ground vibration, a greater understanding of the site specific response to the blast design is needed that is beyond the scope of simple seismographic recordings. By synchronizing the photographic record provided by the high speed motion picture cameras with the airblast and vibration information from digital seismological monitoring, the Photoseis™ technique can be of great assistance in controlling airblast and vibration and optimizing the use of explosive energy for rock fragmentation.

Jan 1, 1990

By Alex Jankovich, Darren Thornton, Sarrna Kanchibotla, Cam Grundstrom

The Porgera joint venture and Dyno Noble have commissioned a joint project to optimise the drill and blast operations to increase the overall profitability of the mine. One of the aims of this project is to increase the throughput of semi autogenous (sag) mill by optimising the blast fragmentation, The work done so far clearly indicates that significant improvements in sag mill throughput can be achieved by optimizing the blast fragmentation. This paper discusses the planning, implementation and results achieved so far in this project.

Jan 1, 2001

By Sayantan Chakraborty, Kaushik Dey, SaKaushik Dey tyabrata Behera

Drilling and blasting is a popular excavation technique in the drift of underground mine. Faster completion of drift reduces the gestation period and thus longer blast pulls are attempted with longer drill holes. This compels the blasters to initiate higher charge quantity with higher confinements and ultimately results into blast-induced cracks beyond the desired periphery line of excavation. Assessment of the extent of these crack networks is difficult and often neglected. Near-field ground vibration models are often used as damage predictors (Dey, 2007, Yang et.al 1993, Holmberg et. Al 1979) but not necessarily deals with the positions of the cracks. Qualitative measurement of actual damage extent often measured using some geophysical tools, namely, P-wave velocity (Tezuka, 1995), seismic imaging (Dey, 2011), bore hole pressure monitoring (Brent and Smith, 1996), electrical resistivity (Grady and Kipp, 1993), GPR (Adams et.al, 1993) etc. Ground Penetrating Radar (GPR) is a similar geo-physical tool, which uses Electro-magnetic (EM) pulse for characterizing the medium. Similar to other geo-physical tools, GPR also comprises of a transmitter and one/multiple receivers to generate the EM pulse and receive the same after reflection/refraction from the medium(s) respectively. After its development in 1970s, GPR gained increased popularity due to its application in many important fields, namely, identification of buried objects, geological characterization, identification of geological disturbances etc. Thus, it is felt that GPR technique can be used to detect the invisible cracks inside the rockmass from the rock surface (wall and roof) itself. Understanding the same, field experimentations are carried out in an underground manganese mine in Central India, which operates on the ‘cut and fill’ method of mining at a depth of around 300m from the surface. Wedge cut blasting is carried out in the horizontal drifts of the mine using suitable blast design. A 1.6 GHz antenna was used for the GPR scanning, in which GPR transmitter transmits signals predominantly of the said frequencies. The signals get reflected back from any type of interfaces between materials in the target area, with different dielectric properties and is received by the receiver part of the ‘trans-receiver’ antenna and memorized in the Data Acquisition Unit (DAU). The data acquired is processed using a software. Ground vibration monitoring of the blasts are also carried out to develop a vibration predictor. The numerical analysis of near-field vibration predictor model results into the estimated vibration levels at the point of identified cracks. Introduction

Jan 1, 2019

By Ronald Joseph

Windows-based automated blast loading systems have long being conceptualised and never really taken off in the surface mining sector. However, with the introduction a windows-based automated blast loading and reporting system onto the Mobile Manufacturing Units (MMU’s) at Debswana Diamond Company operations in Botswana in August 2004, a project to automate blast loading (charging) and reporting ensued. This work was pioneered over three phases at Debswana’s Jwaneng Diamond Mine by African Explosives (Botswana) (Pty) Limited as part of the African Explosives Limited’s (AEL) integrated-mining (i-mining) concept. The first phase of the project involved the blast reporting system, at which time an average amount of explosives were loaded into all blastholes and all blast loading information was saved to a Microsoft Access 2000 database on the MMU computer. The second phase of the project, which ran until the end of the second quarter of 2008, involved manual blast plan loading and reporting system using flash disks, and the third phase which was installed and commissioned in the third quarter of 2008 and is currently operational at Debswana’s Jwaneng Mine, involves the automated blast loading and reporting system via Wireless Local Area Network (WLAN). This system is now routinely used to achieve operational and mining efficiency goals at the mine with respect to blasthole charging and blasting, and this paper briefly summarizes the status of this project at Jwaneng Diamond Mine where this technology is currently being monitored and also illustrates the positive mining impact that this innovation brings to the mining operation, both from an economic and efficiency perspective.

Jan 1, 2009

By Dave Harrison, Phyllis Hasser, Ken Eltschlager

The beginning There was the video:– “Understanding Vibrations from Blasting” – 2002 to 2004 in development – Dale Ramsey ad hoc Public Education committee chair – Available At the ISEE bookstore Public Education and Public Relations Committee • Standing ISEE committee 2004 • Co-Chairs – Ken Eltschlager, Dave Harrison • Purpose: "Develop and conduct programs on public education and public relations. Public education programs will focus on public awareness, understanding, and appreciation of the explosives industry. Public relations programs will concentrate on providing blasting professionals with the tools to assist in the public's understanding of the explosive industry and in the appropriate ways to respond to local community issues."

Jan 1, 2007

The common approach of designing blasts on a trial and error basis is quickly coming to an end. When utilizing the full scale blast environment, trial and error can quickly become cost prohibitive and leaves much to be desired in terms of true blast diagnostics. In these situations testing is usually only continued until a perceived improvement is achieved and when the gross undesirables in blast results are removed. This does does not preclude, however, that further improvements of up to 100% or more can not be obtained.

Jan 1, 1991

By Andrea Brickey, Ethan Marcoux

The South Dakota School of Mines and Technology (SD Mines), located in Rapid City, South Dakota, is one of only a few universities in the United States that offer a Bachelor of Science in Mining Engineering. The Department of Mining Engineering and Management (MEM) at SD Mines teaches courses that introduce students to concepts related to mining, including a course covering explosives engineering. Students are taught the basics of explosives theory and application in the mining and construction industry through a series of lectures and assignments. With limited field experience, many students find some topics difficult; these include: flyrock, ground vibration, timing, and others. Some US mining schools have an experimental mine in which they can simulate field conditions and conduct hands-on training, but not all universities have such facilities. For those without, teaching certain concepts can be more challenging in a pure classroom environment. To counteract the lack of an experimental mine, the mining department at SD Mines implemented Paradigm (Version 18.4.4984.0; McKenzie, 2017) a computerbased blast modeling software to improve the learning environment.

Jan 1, 2019

By Michael Wieland

Delay blasting in underground coal generates shock waves and rifting forces that damage charges remaining in the blast pattern. Damaged charges detonate poorly, raise fume toxicity and reduce coal breakage. Such circumstances could be prevented by using explosives resistant to cross-hole interaction damage. The design of rugged explosives is fraught with contradictory requirements, but tradeoffs related to hard-particle size characteristics prove useful. Hard particles, related voids or trapped bubbles represent reaction nucleation centers which strongly influence the performance of coal mine explosives.

Jan 1, 1992

By Paul Worsey, Gillian Worsey

The explosives industry is about to reach a critical turning point in human resources. The average age of employees of the largest US explosives company is over 50 and an estimated 5,000 engineers are due to retire from the mining industry over the next decade, with less than 200 mining graduates per year nationally. Not just in the USA, this is a worldwide problem. In Canada the Mining Industry Human Resources Council (MIHRC), reported that older mining engineers are retiring early – at the age of 59.5 on average. It predicts that mining companies will need to hire 370 mining engineers by 2016 and 665 by 2021. The Minerals Council of Australia has predicted the need for an additional 86,000 mining professionals and skilled mine workers by 2020, and the Indian mining industry is also facing a shortage of between 2,500 to 3,000 engineers per year.

Jan 1, 2014