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By David N/A Doucet, Colter N/A Angell, William N/A Joa, Kyle N/A Wagner, Catherine N/A Johnson, Marty N/A Langenderfer

The Kingery-Bulmash (K-B) equations are a widely accepted means of predicting air-blast parameters from surface explosive detonations. The parameters predicted from these calculations include incident and reflected pressure, time of arrival, shock front velocity, incident impulse, reflected impulse, and positive phase duration. K-B calculations are based on curve fitting of experimental data and can be used to predict air-blast parameters for explosive weights from less than 1 kg (2.2 pounds) up to 400,000 kg (440.9 US Tons), and ranges of 0.05 to 40 meters (1.9 inches to 131.2 feet). The K-B equations can also determine the parameters for multiple explosive types using scaled distances and relative equivalency to TNT. An experiment was designed to demonstrate if the measured results for incident pressure, time of arrival, shock front velocity, incident impulse, and positive phase duration equal the expected results reported for the detonation of a small quantity of explosive determined by the K-B Calculator. Three surface-detonated 300-gram (0.66 pound) hemispherical charges of Composition C-4 were observed via high-speed imaging and hydrostatic pressure monitoring. The hydrostatic pressure generated from each charge was measured via piezoelectric pressure transducers at a scaled distance of 10 from the charge epicenter, and at elevations of 0.30, 0.61, and 1.22 meters (1, 2, and 4 feet) above ground level. Variances in experimental values from the K-B predicted values were recorded for each measured blast parameter. Time of arrival, which was redundantly confirmed through high-speed imaging analysis and hydrostatic pressure monitoring, showed the highest deviation from the predicted values at more than double the K-B predicted value. This report compares the observed blast parameters from the test series with the expected blast parameters from the Kingery-Bulmash Blast Parameter Calculator. Differences between the experimental and predicted values are reconciled through analysis and discussion of testing conditions, instrumentation setup, and scaling methods.

Jan 1, 2019

By Denard Brandt, Isidro Martinez, Greg Baker, Laura Slattery, Teddy French

The Dos Pobres Mine is a copper oxide heap-leach mine located near Safford, Arizona. Mine production is 180,000 tons (163,293 tonnes) per day with a stripping ratio of 2:1. During the startup phase of the mine, the required fragmentation size was easy to achieve as the ore was highly weathered and fractured near the surface. As the mine depth increased, the proper fragmentation size became harder to achieve due to less weathering and different rock types. Because copper recovery increases as crusher product size decreases, achieving the appropriate product size at the crusher is the operating priority.

Jan 1, 2010

By Hairong Zeng, Matthew Baumann, Shahram Tafazoli, Edmond Chow

Measurement of rock fragmentation has evolved from a completely subjective and manual process to a statistically objective and semi-automated process. However, ultimately, the vision is to achieve a statistically representative and fully-automated process. From the blast optimization perspective, it is critical to receive reliable rock fragmentation results quickly to incorporate into the planning of subsequent blasts. Since manual rock fragmentation measurement methods tend to be time consuming, a fully-automated method is the practical way to meet these requirements.

Jan 1, 2012

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By Steve Dillingham

Blasting crews, explosive product drivers, drillers, blasters, supervisors, and salespeople all arrive daily at customer blast sites in vehicles of every type whether passenger cars, pickup trucks, or bulk trucks. The majority of these vehicles are company owned and re p re s e n t a substantial investment and risk for the company. That may explain why the costs resulting from blasting incidents is often surpassed by those involving motor vehicle accidents.

Jan 1, 2003

By Weiying Zeng, Shouwei Wang, Jinbei Zhong, Xiangdong Meng, Lingtian Meng

"Due to a drainage problem, the Lanzhou to Chongqing high-speed rail line had been out of service during the 2015 wet season, so a drainage tunnel is to be constructed for the line and required to be accomplished before the 2016 wet season. This drainage tunnel is only 5 meters below the line which is in service, therefore blasting vibration needs to be strictly controlled. This paper introduces all theapplied blasting methods, parameters and detonation throughout the entire project, finally bringing in the electronic detonator stagger phase technique and corresponding time difference for detonation."

Jan 1, 2017

By Panagiotis (Takis) Katsabanis, Lyall Workman, Jack Eloranta

The reduction of metallic ores to concentrate consumes a great deal of electrical energy. In the past two decades, a number of case studies have demonstrated a beneficial relationship between powder factor and grindability. However, changes in mill performance cannot be attributed to changes in feed size alone. Blasting energy and the distribution of that energy appears to affect subsequent comminution beyond crushing. This experience has prompted researchers to attempt to duplicate and quantify the mechanisms involved. To date, published reports indicate a measure of success. However, the blast engineer and the mill engineer still lack the tools and basic understanding necessary for full drill to mill optimization.

Jan 1, 2015

By Ethan Steward, Kyle Perry

To test the effects of impact on mine seals, a projectile generator and two seals have been constructed. The projectile generator is a 12-inch (30.5 cm) inner diameter steel pipe with a 4-inch (10 cm) wall, is 8.5 feet (2.6 m) in length, and sealed on one end. Projectiles are propelled by a charge of black powder with a wooden wad and are held in place by foam sabots in the bore. This system, combined with the large bore, allows firing of many different potential projectiles that may be found in an underground mine at a high velocity into the seals.

Feb 1, 2020

By Kristen R. Bingham

"Today, more than ever, drilling and blasting contractors are challenged to manage the ever-changing risks associated with blasting operations. New neighborhoods are encroaching upon mine sites and blasting projects are confronted with increasing scrutiny by permit issuing authorities and nearby residents disgruntled by new construction. The act of transporting explosives material to and from thejobsite is far from easy and trouble-free. At the same time, the pressure to stay in compliance with the growing number of government regulations continues to mount. While new tools and technology are appearing in the workplace to address some of these challenges, losses still occur. Can the datagenerated by this technology help drilling and blasting contractors make better decisions? While basic risk management principles are still applicable, do new tools and technology assist in the effort to prevent losses? What are the downsides? In this age of new technology, is face-to-face interaction still necessary? While technology is certainly a useful component in the drilling and blasting world, can it be helpful in defending claims?"

Jan 1, 2017

By Ron Gilbert

Every day, demand increases with over all population; supply must follow. People must have more food, shelter, and mobility. Raw materials must be mined. Roads, trenches and foundations support the quality of life.

Jan 1, 1996

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 Ann Barron

For millions of people, cold weather is a fact of line – and one that can make a major challenge out of just getting to work. But for those working in the blasting industry, a number of obstacles are created when old man winter blows in. In addition to the obvious concerns regarding personal protection, Mother Nature can throw some very nasty weather at the blasting crew trying to travel with explosives products from the magazine site to the job site. As such, divers need to be familiar with cold, ice, and snow driving conditions both on and off the blast site. It’s critical to know what to expect before you leave. Keep informed of the latest weather and road conditions as they change often; it will help you make the right choice in clothing and driving habits. Remember bridges and overpasses will freeze first even in temperatures above or near the freezing mark due to the effects of wind chill. Plan to take extra time to and from the job site.

Jan 1, 2004

By R W. Thomas

"This paper explores the possibilities of generating radical improvements in the drihing costs andproductivity of blastholes through the efforts of integrated teams as opposed to traditionalcustomer/vendor relationships."

Jan 1, 1996

By Thomas M. Keevin, Gregory L. Hempen, David J. Schaeffer

In an attempt to reduce the potential for fish mortality during the explosive demolition of Locks and Dam 26, Mississippi River, the U.S. Army Corps of Engineers, St. Louis District explored the use of a bubble curtain to reduce the fish kill radius of underwater explosions. Bubble curtains are walls of bubbles rising from a bottom-resting bubbler manifold supplied with compressed air. Demolition engineers have long been aware of the attenuating properties of air bubbles in water. As such, air curtains have been routinely used to protect underwater structures from damage by underwater explosive shock waves. However, their use in protecting aquatic resources during full-scale explosive demolition projects was untested.

Jan 1, 1997

By T Barnes, K D. Sexton, T J. Tope

For the past decade, the U.S. Department of Defense (DoD) has been under increasing pressure from state and federal regulatory authorities to develop management strategies for waste streams generated at its bases, installations, and ranges. Since passage of the Federal Facilities Compliance Act (FFCA) in 1992, concerns have focused in particular on military munitions and energetic waste streams.

Jan 1, 1997

By Luke Thornton, Jack Janssen

An unconventional drill pattern is used in an aggregate quarry to reduce pioneering costs. The site is the Iron Mountain Quarry, Granite Falls, WA., an aggregate quarry with an annual production of in excess of 1,000,000 tons. The problem is to pioneer a forty acre addition of on top of Iron Mountain. The entire area had a vertical relief of fifty to one hundred feet with no level surfaces. How does one achieve the minimum cost?

Jan 1, 1997

By N. Rouse

Underground raises and slots are a vital part of underground blasting operations. Raises and slots are vertical shafts or openings used for ventilation, ore passes, or creating voids in stopes. In the author’s experience, raise and slot designs can vary significantly from operation to operation or even within a single operation, sometimes for reasons unknown. The results of the various designs can differ depending on drilling accuracy, geology, and the explosives used in the design. The purpose of this paper is to summarize the recommendations found in published literature on raise and slot design in one document, while incorporating some of the author’s own experience with optimizing raise and slot designs in underground operations. Some inspiration is also included from burn round designs; small versions of raises drilled horizontally in development blasting rounds. This document includes discussion points on drillhole diameter and depth, pattern design and relief requirements, explosive types and loading recommendations, and timing. Ultimately, this document can be useful to those looking to design a raise or slot blast for the first time or for those looking to improve on the results from the raise and slot blasts used at their operations.

Jan 1, 2024

By Diogo Fonseca, José Manuel, Nuno Fernandes, Blessing Taiwo

This research focuses on enhancing the synergy between blasting and primary crushing operations in quarries. A blast operation at dstgroup aggregate quarry in northern Portugal was simulated to fine-tune blasting techniques aimed at optimizing fragmentation indicators. The methodology involves conducting precise blast drill hole surveys, generating detailed terrain 3D models, and integrating these models into blast simulation software to enhance accuracy and optimize production efficiency. The study applies these simulations to test blasts, evaluating improvements in cost-effectiveness, crusher power consumption, and fragmentation efficiency using both aerial and terrestrial image analysis technology. The quarry key performance indicators (KPIs) guide the blast design simulations, ensuring practicality and relevance. The case study blast revealed that implementing optimum blasting techniques can enhance crusher throughput, reduce operational costs, and improve safety. This paper is part one of a three-part technical series where we aim to create a sampling procedure and establish a reliable baseline for the current state of operation. This baseline will be used in subsequent follow-up technical papers to make recommendations and improvements. The outcome of this study provides a framework for quarry operations seeking to enhance their efficiency.

Jan 21, 2025

By A N. Gupta, C Joginadham, P Shiva Shankar

Cast boosters made with pentaerythritol tetranitrate(PETN) and trinitro toluene(TNT) give high velocities of detonation and are sensitive to initiation even under high pressures. However, the manufacture of the same involves heating of TNT to its melting temperature and mixing of dry PETN in it.

Jan 1, 1996

By Jamie Delgado, Marco Arelano

The changes of bench angles in an Open pit mine has a strong economical impact in the “mining business”, particularly in its cash flow related both to the decrease as well as to the increase of the global bench angle or the inter-ramp angle. The global vision of bench optimization process currently developed by Compafila Minera Zaldivar (CMZ), includes the interconnection of different processes driving to the completion of the designs. Thus five very influential areas are recognised such as: (1) The physical Surrounding terrain, (2) the strength parameters, (3) the observational model, (4) the acceptability criteria and (5) the operational considerations. One of the important variables affecting this process is Drilling and Blasting (D&B). Increasing the bench angle requires to optimisation of D&B. To achieve this efficiently controlled sub processes must be defined. Three (3) steps can be defined: (a) design parameters, (b) explosive energy distribution and (c) operation results. To control and improve said steps quantitative evaluations of D&B must be performed. One valid evaluation is the “near field vibration monitoring technique” (at bench level). With the application of damage criteria, measurements and modelling of particle velocity a proper definition and optimisation of stages (a), (b) and (c) was achieved, The use of this methodology has enabled to CMZ to successfully increase the inter-ramp angle in three degrees thus obtaining a saving of US$ 36 million in the waste material removed. Also, the efficient control of the bench slopes has resulted in the improvement of the fragmentation operational results. This has resulted in a 26Oh increase in the ore processing by saving energy in the primary crusher due to its performance improvement.

Jan 1, 2001