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By R. F. Favreau, P. Favreau

Rock excavation is the first process in the cycle of operation of a mine, and efficient blasting is paramount to the profitability of the mine. The traditional way to design blasts has been by trial and error, based on the experience of the designer. This is probably the only important engineering practice which continues to be done without a precise engineering technique. The efficiency of most other mine processes has been improved by the use of high-tech, while a majority of blast design has not yet profited from the advantages of the computer. However, with the advent of the high-tech blast simulator Blaspa, it has become possible to design the parameters of the blast according to normal engineering practices. Over the last 50 years, the chemical and physical mechanisms which occur during a blast have come to be identified; they are reviewed in section B. Although these mechanisms are complex, they have nevertheless been expressed in terms of mathematical equations which have been assembled together in the computer to create the blast model Blaspa.

Jan 1, 2002

By D T. Froedge

At the 1990 Symposium of the Society of Explosives Engineering, D.T. Froedge, President of GeoSonics Inc., presented a paper entitled "Differential Topographic Vibration Isomapping", which detailed the capabilities of GeoSonics' new Iso-Seismic Service. In this paper Mr. Froedge described how one hundred or &ore free-standing miniature seismographs called Micro-Seis Units, randomly positioned around a blast, could accurately reveal the effects of sub-strata geology on surface ground vibrations. The paper went on to note the "regression analysis of scaled distance versus recorded particle velocity" as being an inadequate predictor of peak particle velocity. This is due to the fact that the calculated "regression analysis" formula for any site is predicted on the wars; case assumption because of a homogeneous and symmetrical sub-strata geology, a condition that rarely, if ever, exists.

Jan 1, 1992

By Dale S. Preece, Stephen H. Chung

Electronic detonators and the attendant precise detonation timing that they facilitate are having a measurable effect on rock blasting in terms of improved fragmentation and vibration control. These improvements are increasingly well documented which is driving the expanding use of electronic detonators. In spite of the growing body of positive evidence concerning the benefits of precise delay timing, very little work has been done to document the impact of electronic detonators on the movement of rock. In this study 3-D computer programs, used to predict blasting induced rock heave, including the effects of detonation timing, are used to simulate the effect of precise timing on rock movement. Implementation includes quick, precise timing between blastholes going down a row and then much longer delays between rows of blastholes. For example an effective blast design might call for precise 3 ms delays between blastholes along a row and then 60 or 72 ms between rows. Several options are studied in this paper using computer simulations to draw some conclusions about the underlying physics affecting the process and how precise timing might have a positive impact on blasting induced rock motion.

Jan 1, 2005

By D T. Froedge

With successive generations of the Iso-Seismic System, we are acquiring more and more information about the actual behavior of blast induced ground, and airborne vibration, as it propagates through the environment. Some of the original “truths” that have been long accepted may have to be \revised.

Jan 1, 1995

By Charles Dowding, Cathrine Aimone-Martin

This article summarizes an investigation of the structural response of a brick façade home in New Mexico. The subject Ricter residence was located some 1100 to 1400 ft away from an aggregate quarry, and was subjected to a maximum peak particle velocity and air blast over pressure of 0.29 ips and 122 dB, respectively. Superstructure (corner) and mid-wall responses to blasting and human induced activities were measured. An existing exterior crack in the brick work was instrumented to measure crack width response to blasting, human induced activities, and environmentally induced changes in temperature and humidity. Crack and structure response data were correlated with ground velocity and airblast excitations. Amplification of ground motions at the upper structure were calculated and compared with values for typical wood frame structures. The natural frequency and damping characteristics of the structure were determined to compare with measured amplification values. Wall strains produced by bending and inplane tension strains were computed from upper corner structure response and compared to failure strains for drywall and brick veneer. Calculated strains were found to be far lower than those required to crack brick and environmentally induced crack response was found to be far greater than that caused by blast induced ground motion or airblast overpressures

Jan 1, 2005

By D Wilson, R R. Vandebeek, R A. Bowes

"As business opportunities are sought around the world, the explosives industry must oftengrapple with the United Nations Transport of Dangerous Goods Recommendations.Canadians have problems in this area that are similar to those of other countries. Thispresentation outlines, through a case study, how a container for shipping ""explosives"" wasdesigned, tested and approved for use by the Chief Inspector of Explosives, the""Competent Authority"" for Canada."

Jan 1, 1993

By Jerry Wallace

The goal: At an industrial site, sever a well pipe containing an interior obstruction in a timely, cost effective manner by using a shape-charge to cut through the casing more than 50 meters below ground surface from the outside, doing so while inside a larger pipe, without damaging the larger pipe. The problem: Pumps and retrieval tools stuck nearly 50 meters below ground surface inside a 305 mm diameter by 9.5 mm wall thickness water well casing. The well, depth of 185 meters, had to be inspected for contaminates then properly decommissioned before industrial expansion could take place overhead. The limitations: A 508 mm diameter pipe had been driven around the 305 mm pipe to a depth of 63 meters. The usable internal diameter of the larger pipe was about 480 mm while the smaller pipe had buckled at one point forming a 350 mm wide spot. The charge thickness was limited to less than one-half the difference. Additionally, water that filled the annular space between the two pipes had to be displaced for the charge to work properly. The solution: Enlist the support of the shape-charge manufacturer to design, build and test a charge to work under the conditions present, then make it work in the field.

Jan 1, 2000

By Matt Slezak, Tristan Worsey, Nathan Rouse, Kyle Hall

As everyone knows, blasters are required to file blast reports of every blast for regulatory purposes. To this day, the authors see many handwritten blast reports. Handwritten blast reports are notorious for containing errors or omissions. This is not because the blaster intends to misreport information. It is because blasters have many tasks to complete in a day, are sometimes in a rush, and could accidentally miscalculate data, omit items, or record incorrect data. In most cases, blasters do not suffer consequences to these errors because blast reports are seldom reviewed in detail. In some cases, such as when a blasting operation undergoes some sort of litigation process, the reports are reviewed in detail and the blaster is ultimately held responsible. If the reports contain errors, the blaster can be fined, have his/her license revoked, or worse. Electronic blast reporting and centralized data management can help reduce or eliminate the potential for accidental blast reporting errors to occur. This paper presents many ways that electronic blast reporting can reduce or eliminate blast reporting errors, decrease time and extra costs spent reporting, and improve efficiencies in the field and the office.

Jan 1, 2018

By A. Karadogan, G. Tuncer, A. Kahriman

Determination of optimal blast parameters have been the priority act for blasters on the field due to financial and technical properties of the operation. Therefore many researchs were done to establish a general formula for many years. These intends could reach some empirical and numerical design frames consisting the rock, geology and explosives properties. Blasting parameters have to be adjusted according to the desired fragmentation rate especially on the mines where particle size distrubition after blasting has a great importance. Therefore the blast designs have to be evaluated considering the particle size distribution after the blasts. The Kuz-Ram model which was modified by Cunningham is one of the tools for estimating the particle size. Although it doesn’t give an accurate result, it can be very succesful on modifying the blasting design parameters by establishing a back correlation between the blasting parameters and the exact particle size distribution results which can be easily achieved by digital image processing system. Within the scope of this study, the particle size distribution after blasting was assessed by Split-Desktop digital image processing system and bench blasting parameters were studied considering the desired particle size distribution at Espey colemanite mine using Kuz-Ram and digital image processing system combination to determine the specific blasting parameters for this site.

Jan 1, 2005

By Raj K. Rajamani, Solomon A. Tucker, Michael K. McCarter

"In a study aimed at exploring possible improvements in operating performance at an Open Pit Copper (OPC) mine in the western U.S., the impact of blast energy changes on crushing performance was evaluated. OPC feeds its 3-stage crushing plant in 12-hour-day shifts with skarn ore from three domains: Pit_B (B), Pit_S Low-Grade (SLG) and Pit_S High-Grade (SHG), in the blending ratio 1:1:1 (B/SLG/SHG). Thecrushed product is fed to a 2-stage ball mill circuit. "

Jan 1, 2017

By Maurice Hunter

The paper outlines recent design developments in the computerization of surface crawler drills for the quarry industry. It references the technology firstly developed for the underground mining and construction industry, where automation and computerization has been in demand for a number of years.

Jan 1, 2003

By Ph. D. Favreau, Favreau Patrice B. Eng, R. F.

Geology is important in mining by helping to identify the rocks which contain sufficient valuable ore to justify their excavation. Geologists give a geological name to each rock type, so geology is a player in blasting; when a blaster has successfully blasted rock of a given geological name at a former site, and he later has to blast rock at another site whose rock has the same geological name, then his first trial often is the same method as he used at the former site, since the geological name of the rock is the same

Jan 1, 2019

By Patrick D. McLaughlin

Crater blasting techniques have had relatively little application in the surface mining industry. This is not surprising, considering the geometry required to efficiently use cratering. The more widely known blasting operations that employ some form of cratering are listed below.

Jan 1, 1992

By Ed Clah, Catherine Aimone-Martin

The vibration response of a 30 in. diameter high-pressure (845 psi) natural gas pipeline to 11 coal mine blasts was measured. The X-52 steel pipeline was buried 7 ft. below the ground surface. Ground and pipeline motions in terms of velocities were recorded on the pipeline, in the ground adjacent to the pipeline, and near the ground surface directly above the pipeline. These data were used to estimate the maximum stresses and strains in the pipeline occurring during the blasts. Pipeline standoff distances varied from 264 ft. to 3720 ft. Two blast hole layouts and timing schemes were used. One represented highly confined blasts to limit movement of the shot overburden that generated high ground motions at the pipeline. The second represented patterns that provided greater relief and lower the ground velocities at the pipeline.

Jan 1, 2003

By Jean-Guy Levaque, Robert Ethier, Ron J. Elliot

This paper presents data gathered during a comprehensive study on the impact of improvements to fragmentation in a major Limestone quarrying operation. The full impacts of gains in fragmentation are tracked through the mucking, crushing, and grinding phases of the operation.

Jan 1, 1999

By Chad Ducey

The proper utilization of energy in an explosive column is of paramount importance to the success of any blast. Historically, Powder Factor (the weight of explosive per mass or volume of material to be blasted or its inverse), has dictated the blast design. The concept of Energy Factor is a more effective method to design a blast. In order to utilize explosives efficiently, the energy contained in any given product must be quantified. The Powder Factor method, although historically successful, assumes that a pound of cast pentolite affects the material to be blasted the same as a pound of ammonium nitrate / me1 oil (ANFO.) Years of experience and scientific testing have led the blaster in the field to believe otherwise. The next logical technological step is Energy Factor. The Energy Factor method that will be discussed in this paper takes into consideration not only the weight of the explosive, but also the weight strength (Cal/g) and the density (g/cc) to yield a constant relative Energy Factor. The result of such a method is a factor that can be used in the field exactly the same as Powder Factor, but that reflects the relative energy of any given product in terms that will reflect the relative cost benefit of that explosive selection. The Energy Factors associated with different available explosives make it possible to compare the difference in the amount of energy per loaded pound in each unit length of borehole. This paper will examine the concept of Energy Factor in an in depth manner and also compare this quantification method to that of Powder Factor. It will also demonstrate the value of using Energy Factor and how it can improve the efficiency of a blast design. The misconceptions that come along with using Powder Factor will be examined and comparisons will be made between boreholes loaded using Powder Factor and those that are loaded using Energy Factor. This paper will clearly define the differences between these blast design methods and allow the reader to realize the production, quality, and economic advantages of using the Energy Factor method.

Jan 1, 2000

By C B. McCampbell, R W. Jr Bickes

Sandia National Laboratories has developed a semiconductor bridge (SCB) igniter for the ignition of a variety of explosive materials. When subjected to a low-energy current pulse, the bridge bursts into a plasma causing rapid ignition of the explosive material pressed against the bridge. Despite the low energies required for ignition, SCB components have proven to be explosively safe, meeting both no-fire and electrostatic discharge (ESD) safety requirements.

Jan 1, 1991

By V. Petr, G. G. W. Mustoe, T. G. Rozgonyi

We introduced a numerical method that is applicable for the analysis of static and dynamic deformations of elastic media. In this numerical study, each elastic body is modeled with a system of several hundred rigid particles that are joined together elastically. Maximum shear stress fields due to external loading are obtained and compared with those obtained by photoelastic experiment. Preliminary results are presented for the stresses generated in circular disk shaped bodies idealized with connected systems of particles. Extension of this simulation method to fragmentation of brittle materials is also illustrated in an example.

Jan 1, 2000

By Daniel Ko, Ian Bell, Shahram Tafazoli, Bahram Sameti, Aylin Azmin

Image-based remote sensing of rock fragmentation in mining and quarry applications essentially treats each rock in the image as a data object in order to determine the rock size distribution. An obvious challenge after rock delineation in a 2D image is the scale of the delineated objects. Conventionally, either objects of known size are placed in the scene or parallel laser pointer are used, both making some assumptions, to calculate scaling factors. These assumptions are applied to the whole scene rather than sensing individual rock attributes.

Jan 1, 2015

By Thomas Zukovich, Robert Morhard, Thomas Gelormino

The ExploTrack Explosives Tracking System is a sophisticated integration platform designed to track explosive products in both fixed locations and mobile environments globally, in real-time, on a 24/7 basis. The system utilizes active and passive RFID (Radio Frequency Identification Devices) installed within or applied upon explosives materials and explosives articles and incorporated within explosives packaging and logistic transport mechanisms. The system is designed for real-time inventory on an enterprise level and also across the globe providing explosives tracking, monitoring and explosives security from manufacturing throughout the logistics supply chain through use. The system can also track and monitor all known persons coming into contact with RFID enabled explosives materials and articles at the production level, at the magazine level, at the logistics level and to final use enabling a complete and real-time auditable chain-of-custody.

Jan 1, 2007