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By M Lemieux, R Mason

The SABREX blast modeling program was introduced to I.O.C.C.'s Carol Lake Iron Ore Project in December 1987. As part of CIL's Technical Services, SABREX was used to implement an optimization program designed to analyze and introduce various grades of MAGNAFRAC at a constant pattern while maintaining acceptable blast results.

Jan 1, 1989

By S. Mansfield, A. Sharma

At a large open cut copper mine, in pit crushing and conveying is used to shorten haul routes and minimise stockpiling of ore. This strategy decreases capital expenditure by reducing the number of haul trucks and excavators required and reduces the need to rehandle ore from stockpiles with a secondary load and haul fleet, with an overall goal of lowering operating costs and carbon emissions. As the mine has developed and expanded, it was necessary to extend the conveying network and install a fourth, semi-mobile crusher to increase the output of the operation, while maintaining the operational efficiencies. This required the blasting of a new tipping bench and pocket for the installation of one of the largest and most powerful semi-mobile, crushing plants. Fed by 360 tonne (396 ton) ultra-heavy class haul trucks, the KB 63-130 Pro gyratory crusher is the highest capacity available in the market. This paper describes the holistic process that was applied to model, design and execute the blasts required to create the pocket for the semi-mobile crusher, the surrounding tipping bench, plus the conveyor corridor and access ramp used by the ultra-heavy class trucks.

Jan 1, 2024

By Paulo Couceiro

Highly non-ideal explosives usually tend to react expressively below their ideal detonation velocities. In these cases, dimensional effects and product heterogeneities become important to proper model the detonation state. Although Direct Numerical Simulation (DNS) techniques can provide a complete and exact solution for this problem, its actual computation cost is still not practical for industrial applications. In order to minimize these constrains, a simplified two-dimensional steady non-ideal detonation model for cylindrical stick explosives is developed. Based on an ellipsoidal shock shape approach, the proposed model uses the quasi-one dimensional theory for the axial flow solution and combine the post-shock sonic flow criteria with some limiting conditions for the explosives’ unconfined radius determination. Due to its attractive fitting capability for unconfined detonation experimental data, the model offers the possibility to predict the non-ideal detonation state for any diameter, resulting in a full mapping of the diameter-effect curve of the explosive. Thus, the proposed engineering approach is used to model the main properties of some of the most common ammonium nitrate-based explosives used in mining and quarrying industries, including the complete axial flow solution.

By Marlyn G. King, Robert L. Martin

Blasting activities in all four pits at Thunder Basin Coal's Black Thunder Mine are focused on cast blasting. With widths varying from 190 feet to 265 feet and bench heights varying from 90 feet to 175 feet, casting efficiencies vary with different geometry's. For example, the percent cast to final in the 200 foot pit is on the average higher than the 270 foot pit. The powder factors are somewhat higher in the narrower pits, thus increasing the cost of blasting. This leads to a very detailed look at the actual benefit of cast blasting and the associated cost of these benefits.

Jan 1, 1995

By Karl E. Burgher

Accidental explosions occur throughout the world. They can happen at chemical plants, fireworks plants, grain depots, or as a result of collisions involving volatile or hazardous chemicals. It is interesting, as we know as blasters, that we can take two very harmless products and mix them under certain conditions and produce a violent explosion. It is often very difficult for the investigator to determine the magnitudes of blasts after the fact. However, an estimate must be made to settle vibration and airblast damage claims. The blasting consultant or technical representative is often called upon to act as an expert to mitigate these claims.

Jan 1, 1993

By Hubert den Dikken

ache, especially when it comes to forwarding of small quantities. Air transport is limited to 1.4 explosives on cargo aircraft and 1.4S classified explosives on passenger aircraft, so most samples cannot be transported by air. Ocean transport is a possibility, but due to stowage and segregation regulations of the IMDG code, a very expensive one. Road transport is often the only solution, but high explosives require special trucks with licensed drivers. The solution to these logistic problems is solved by creating a 1.4S (Class C) classification for all high explosives, when packed in special containment vessels.

Jan 1, 1995

By Baron Fidler, Dave Lilly, Matt Budin

Cumulative sum (CUSUM) statistical process control methods have been used in many industries to monitor quality control results. CUSUM charts are a method to determine when small changes in data indicate a major change in results. E.S. Page at AT&T developed the method in 1954. In many blasting situations, vibration and air blast readings vary slightly from blast to blast. Whether the change is significant or not can be hard to interpret from the raw data. CUSUM charts can assist in determining whether a major change is taking place and when the change began.

Jan 1, 2009

By Syed M. Tariq, Paul N. Worsey

Pre-splitting is now widely used to minimize overbreak and to protect final surface rock excavation profiles in large scale civil construction projects, open pit mining and quarrying. Jointing has been shown to affect the success of pre-splitting and the smoothness and integrity of the resulting rock face. Many facets of jointing have been investigated in detail, including the inclination of joints with respect to the desired pre-split plane, the effects of various filling materials, etc. However, the effects of joint frequency and spatial positioning has been paid little attention. The paper addresses this issue.

Jan 1, 1995

By Frank Wilder, Mark Ferrero

One of the challenges currently facing the explosives industry is how to transition its workforce and its business systems to respond to the increasing pressures for improved inventory and records management. The pressures applied by many U.S. federal and state agencies, such as the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and the Department of Environmental Protection (DEP), as well as regulatory agencies around the world, are increasing the need for accurate inventory accounting of explosive materials and blast documentation. With blasting companies now facing regular documentation audits, potential liability issues may arise due to the inconsistent or missing documentation.

Jan 1, 2006

By Kenneth Eltschlager

Post-blast assessment techniques using off-site data which includes location, seismograph and photographic data were discussed during the Blaster’s Weekend at this year’s ISEE Conference. Blast and property locations with commonly available GPS units allow for the spatial relationships surrounding the blasting to be documented. When distances are coupled with the charge weight per delay, the scaled distance can be calculated to any structure for either compliance with the rules, or to project limitations. When blasting seismograph data is obtained, the scaled distances are then able to be plotted against ground and air vibration levels for post-blast assessment purposes.

Jan 1, 2007

By P D. Katsabanis

Image analysis has been proposed to be an accurate and convenient means of measurement of blast fragmentation. The paper compares the results of image analysis to screening using laboratory scale rock piles. The muckpiles ranged from uniform distribution samples to well graded samples following the Rosin-Rammler distribution.Deviations between screened and imaged distributions were observed in most cases due to the loss of fines. Addition of fines in the system improved the result derived by image analysis considerably. It is suggested that techniques for the prediction of fines be evaluated for modifying the size distributions produced by image analysis.

Jan 1, 1999

By Bill Runner, James T. Ludwiczak

During the last few years, there has been a flood of local, state, and Federal government regulations concerning blasting. Many of the laws and regulations were written by individuals who know little about explosives, the purpose of blasting, or blasting vibration and damage. I feel that the special interest groups responsible for some of these regulations are not trying to regulate blasting, but to stop it completely by unreasonable, non-flexible, regulations. The most recent being the Office of Surface Mining regulations that are already spreading to the quarry industry and will, no doubt, spread to all blasting involving disturbance of the surface.

Jan 1, 1979

By Pierre Mousset-Jones, Jaak Daemen, Songlin Zhang, Jon Hurley

Most western United States open pit gold mine ore bodies are disseminated deposits. The mineralization is so irregular that it is difficult to visually identify the ore/waste boundary. Blast hole samples are used to interpolate digging polygons based on the pre-blast position of the bench. Dilution caused by blasting is of major concern at these mines, since blast movement can mix and dilute the ore and move it beyond flagged digging polygons established on the blasted rock according to their pre-blast location. Typically, mines try to reach a compromise between blast fragmentation and movement.

Jan 1, 1994

By Robert E. Miller

Mass blasting of open stopes and pillars is a normal operating practice at Isa Mine. Three main parameters are used to classify the types of mass blasts. These are type of explosive used, blasthole diameter and system of initiation. Both electric and non-electric initiating systems are currently employed. The advantages gained by large firings are many. More efficient utilization of manpower, due to the concentrated and continuous charging, is achieved. There is no requirement for men to re-enter areas where localised ground conditions may have deteriorated and exposure of ringfirers to stope voids is reduced.

Jan 1, 1980

By Richard J. Mainiero, James Q. Wheeler, Lewis H. Kopera, Yael Miron, Solin S. W Kwak

The research reported here was part of an effort to evaluate the safety of a process to recover TNT from MK-9 depth bombs by the autoclave meltout process. In this process the depth bombs are heated to 121oC so that the TNT will melt and run into a vat. Unfortunately, asphalt lining the inside surface of the bomb also melts and flows out with the TNT. Prior to this study, it was not known what effect the asphalt contamination and the higher than normal process temperatures (121oC) would have on the sensitivity of the TNT.

Jan 1, 1996

By S Burchell

During the past few years, high-speed cameras, laser surveying equipment and photogrammetry have become standard tools for recording blast geometry and results. While laser profiling yields accurate 3-D measurements, most cameras capture only two-dimensional images. Attempts to extract 3-D information from photographs have been unsatisfactory. Recent advances in electronic imaging and computer programming have made it possible to develop a 3-D computer based analysis system which can capture and measure 3-D images quickly and accurately. This paper describes the technology to create 3-D images and to analyze blast geometry before, during and after the blast.

Jan 1, 1992

By Paul Worsey, Ron Ecklecamp, Scott G. Giltner, Ronnie Inman, Terry Drechsler

A blast monitoring program conducted at Chemical Lime Companys new lime calcining facility near Ste. Genevieve, Missouri is discussed. The purpose was to develop blasting criteria for the construction and operation of the lime plant within the quarry operated by Tower Rock Stone. Further, it was imperative to accommodate production requirements into the blasting criteria. The major concern was the effect of blasting on the curing of green concrete during the construction of the storage silos and kiln stacks. In addition to discussing the susceptibility of curing concrete to blast vibrations, the paper also details how this varies with time.

Jan 1, 1996

By K. G. Holley

Blasting is usually required to produce easily-excavated broken rock, while leaving surrounding rock masses as undamaged and stable as possible. In mining applications, it is common to utilise production blasting in the centre of an open pit, and specially developed limits blast designs when blasting adjacent to the excavation perimeter. In open pit blasting, limits blast designs generally include pre-splitting, trim blasts, or buffer blasts, all of which are designed to limit, or eliminate, damage beyond the designed pit wall. This paper reports on the findings of a study of the profile of damage in rock masses surrounding blasts, determined by a combination of vibration monitoring, displacement monitoring using extensometers, and video inspection of open holes drilled at various distances behind blasts. The results obtained suggest that the profile of damage may extend for the full depth of the bench, for distances of up to 12 to 15 metres behind blasts. This suggests that entire berms may be affected by blasting, displaying loss of friction and cohesion along joint and fracture planes. The study has considered production blasts and trim blasts with small diameter blastholes and pre-splits.

Jan 1, 2004

By S S. Kahlon

India is a large and growth market for explosives and accessories, which has dramatically changed from complete import dependence to self sufficiency, and now has an exportable surplus. The largest single user is coal mining which is continuing to show a healthy growth with opencast mining becoming increasingly dominant. The explosives industry has kept pace with mining and today all the well renowned explosives technologies of the world are available in the country. While slurry explosives are popular in large diameter, NG based explosives continue to be preferrred in small diameter usage. Emulsion explosives have had a good market response. ANFO usage is limited due to local reasons. As the mine size is increasing, the demand for bulk-on-site explosives is growing. Prices of explosives and accessories are cheap compared to international levels. The user industry is mainly Government owned mines whose profitability is not satisfactory. Explosives industry is over licensed in terms of manufacturing capacity, which is likely to put pressure on the viability of some of the explosives manufacturing units. Scope exists for optimization of blasting parameters through the use of computerized blasting models. The explosives industry is faced with new challenges and opportunities.

Jan 1, 1987

By Ruilin Yang

Techniques for the study of blast vibrations, such as monitoring, analysis, and modeling are often misused between near field and far field blast vibrations. This paper discusses the differences between near-field and far-field blast vibrations in terms of these techniques. A typical example of a near-field blast vibration problem is a blast vibration in the crest of a new highwall behind a cast blast. In such a case, the blast can be a couple of hundred feet long and the distance from the blast holes to a monitoring station may only be 100 feet or less. In this situation, the size or spatial geometry of the blast is not negligible compared to the distance from the blast to the vibration monitoring point. On the other hand, a typical example of a far-field blast vibration problem can be a quarry blast with a nearby residence house. In this case, the distance from the blast to the house may be several thousand feet. The size of the blast is less than a couple hundred feet long and negligible compared to the distance from the blast to the vibration monitoring point.

Jan 1, 2007