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By John M. Bolger, Keith E. McMaster

Excessive salt fines are undesirable in underground salt mining as they are considered a costly waste byproduct. This paper describes an extensive explosive application program conducted at The Canadian Salt Company Ltd, located in Pugwash, Nova Scotia, Canada. The prime objective of the program was to reduce the quantity of fines generated from this company’s underground production blasts. The program was known as the “The Fines Reduction Program”.

Jan 1, 1996

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 J. Esterle, J. Kruttschnitt

Fragmentation modelling in soft rocks presents a challenge due to their propensity to further fragment after blasting during normal handling. Coal and some iron ore deposits are examples of materials that undergo significant degradation during the extraction, hauling and dumping process of the mining operation. The Kuz-Ram model is an empirically derived predictor of size distribution from blasting hard rock. Little breakage occurs during excavation and subsequent sizing of hard rock, so the measured Run of Mine (ROM) size distribution is essentially the same as the post-blast (before excavation) size distribution. However, for soft rocks, each step of the excavation and hauling operation imparts energy to the rock particles so the measured. ROM size distribution will be significantly different from the postblast size distribution. In order to calculate the ROM fragmentation at any stage of the extraction (or sizing) operation, the JKMRC has developed a model that combines both blast fragmentation and degradation through subsequent handling.

Jan 1, 2001

By A B. Jr Nunn, W C. Gould

Good community relations is a major concern at this central Virginia aggregate quarry. In this paper, the authors describe the use of a new electric millisecond delay initiation system that has reduced the average level of vibration by 27% since its use began in late 1984.

Jan 1, 1986

By Hu Wenjun

This paper changes the section of copper of copper to aluminum adapter bar into aluminum plate covered one face or double face with copper coat, and changes the conductor material of knife switch, fuse box, plug and socket into steel plate covered one face or double face with copper plate, and manufactures the composite (two layers or three layers) metal plates by means of explosion welding with the plates installed horizontally. Introduced in this paper are the blasting designing technique, manufacturing process and the electrical performances of the explosion bonded products. Besides, this paper presents the designing and manufacturing technique of cumulative charges and their time detonating units for cutting off the retired nuclear submarine pipes. Experiments on cutting off the stainless steel pipes by cumulative flow and on the time detonation are made. Keywords: explosive welding, electric, explosion bonded products, retired nuclear installation; pipe; blasting cutting; cumulative charge; time detonation

Jan 1, 2000

By C. Pelley, S. Kelebek, G. Kunzel, P. Katsabanis

Small blocks of granodiorite have been subjected to blast loads from a single borehole and from a series of boreholes detonating at various timing intervals. The damage of the blocks was assessed through P-wave velocity monitoring, measuring the change of the point load strength index of the rock after dividing the large blocks into smaller ones and measuring the work index of the material at different distances away from the blasthole. Numerical modelling with the AutodynTM code enabled visualization of damage. It was shown that damage is optimum at a small delay time between successive holes while it drops rather drastically after this point.

Jan 1, 2003

By John Manka

Emulsion manufactures often spot buy the diesel fuel used in their fuel phases from various sources. Because their diesel source changes, there can be large fuel variation which may affect the quality of the resulting emulsions. This paper shows that the diesel fuel used in manufacturing emulsion explosives has a significant impact on emulsion stability and that the fuel additives dosed into the diesel fuel as it is made also have an impact on the emulsion characteristics and stability. We found that fuels with higher distillation ranges improve emulsion stability. We also found that while none of the diesel fuel additives affected the initial formation of the emulsion, some fuel additives did affect the characteristics and stability of the emulsions as measured by emulsion viscosity, droplet size, high and low shear testing, bin storage testing and freeze thaw cycling.

Jan 1, 2002

By Dale Preece, Stephen Chung

Development of DMCBLAST-3D is continuing and now includes the capability to simulate the detonation of multiple blastholes in multiple rows that make up a conventional bench blast, either in a rock quarry or a surface coal mine. DMCBLAST-3D is a three-dimensional extension of the proven twodimensional rock blast modeling code, DMCBLAST. DMCBLAST has been under development since 1987 and has successfully predicted the physics, mechanisms and results of a number of different types of rock blasting including, coal mine bench blasting, mineral mine choke blasting and underground stope blasting. Substantial effort has gone into the qualification and verification of DMCBLAST by comparing computer code predictions with real blasts in the field. Comparison with field data has also provided significant guidance to the development of the code.

Jan 1, 2002

By Harry Verakis, Thomas Lobb

A great deal of information has been presented and published on the danger from flyrock created from blasting operations. The creation of flyrock is not specific to any one blasting operation. Flyrock is certainly not a stranger to blasting operations conducted in the mining industry and its effects are well known. Flyrock is among the leading causes of mine blasting injuries. Awareness and diligence is the message that must continue to be stressed and followed to reduce the potential for creating flyrock from blasting operations and to reduce the hazard it presents. A recent accident that resulted in a serious injury at a limestone mine in Pennsylvania bears witness to the ever-present danger of flyrock created from blasting operations.

Jan 1, 2007

By Salah A. Taqieddin

The blast casting technique of removing overburden is an innovative technique which was successfully used in the mining of certain surface coal and quarries. This method was found to be efficient in minimizing the labor and equipment cost while accelerating mining operation with safety. This method was successfully applied to horizontal as well as to dipping coal seams. Also it was practically applied to single as well as to multiple ore bodies

Jan 1, 1992

By P Albert

A wedge-shaped underwater rock plug has to be blasted in order to tap the reservoir and furnish water to a new underground powerhouse at Manicouagan-5. The paper deals with the design and engineering aspects of drilling and blasting of this plug where the topographical configuration is extremely difficult. In this study small diameter vertical holes are considered with the OD-method and a fixed platform is recommended for drilling and loading operations.

Jan 1, 1984

By FM Murray

SAFEX International is a global organisation with more than 85 members, all of whom are manufacturers of explosives. On joining each member signs a declaration saying that they are willing to exchange information with regard to any accidents or near misses they may have in order to prevent the recurrence of the incident. SAFEX International was formed 50 years ago in Europe and has now built up a database of more than 700 accidents in the explosives business. Once every three years, an International Congress is held in which members address specific safety themes associated with the explosives industry, and also give details of "what went wrong?", "why?", and lessons learned. The next Congress will be held in Amsterdam between the 29th May and the 1st June 2002. This paper describes the operation of SAFEX International, which is dedicated to the international exchange of experience on industry connected accidents of the explosives business.

Jan 1, 2002

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 Francis O. Otuonye

A time series and system analysis modeling technique was applied to signals from strain egages mounted on a fully grouted resin roof bolt and signals from accelerometers mounted on the bolt head and roof rock to determine the roof bolt's response to repeated blast loading. The derived model gives a comprehensive quantitative description of the modes of vibration of the roof bolt response to each blast loading. The damping ratios and natural frequencies of the modes of vibration can reveal the alteration of the process dynamics due to the deterioration of the roof rock and can be used to identify the incipience of instability in the roof bolt system.

Jan 1, 1987

By P A. Gibson, J R. Brinkmann

The South African gold mining industry fires approximately 800 000 sloping blastholes daily. A programme aimed at characterizing the stope blasting process is underway in order to identify areas for improvement and to provide blasting related information for the design of mechanized sloping systems.

Jan 1, 1985

By Dale S. Preece

A discrete element computer program, DMC (Distinct Motion Code), has been used for several years to simulate blasting-induced rock motion. Recent enhancements of DMC's capabilities have included addition of an algorithm that couples together rock motion and gas flow. This allows the user to specify a particular explosive which also specifies equation-of-state and other parameters necessary to model explosive gas flow from the blastwell. Rock loading by the flowing gas is calculated automatically. The mechanism for calculating the rock loading is the subject of this paper. The rock motion effects the gas flow calculation by changing the porosity. DMC is currently being used on a SUN SPARCstation 2 computer workstation.

Jan 1, 1993

By Stephen H. Chung

Direct visualization of rock movement during blasting is an important key to understanding the blasting process, as well as optimizing blast designs and explosives performance. To achieve this, a digital camera system (HSIS-500) has been built. It is a custom made high speed solid-state camera employing an advanced charge coupled device (CCD) and dynamic random access memory (DRAM) technologies. It handles like a regular video camera but requires no film or tape as the image is recorded in digital form on memory chips and transferred to the system hard disk for storage. The system consists of two components: the camera body and hardware, and the image processing unit.

Jan 1, 1996

By Zhang Shixun, Wang Xuguang, Wang Guoli

A massive millisecond blast at an open-pit mine of large scale can be realized by using the blasting technology of pre-loaded explosives, which can enlarge production scale, reduce the frequency of blasting and of large production equipment movement, and raise the production efficiency. The reason why application of this technology is restricted at high sulfide ore deposits of variable and complex geological conditions is that an exothermic reaction will take place when explosives contact sulfide ores, which could lead to accidents such as spontaneous burning and detonation of explosives pre-loaded in boreholes, influencing blasting and production safety. The thermal decomposition reactions of emulsion explosives of different prescriptions in contact with pyrite have been studied by differential thermal analysis (DTA), kinetics parameters calculation and accelerating rate calorimetry (ARC), and on the basis of the above studies, the safety of emulsion explosives used in sulfide mines has been evaluated with the safe contact time of different emulsion explosives with pyrite determined.

Jan 1, 1998

By C. Partouche, T. Bernard

Blasting engineers are mainly concerned about fragmentation issues. Even further, this is the final goal of using explosives. A lot of models have been developed for controlling fragmentation distribution, but most of the time, they are based on physical phenomena using field data as input for rock characteristics. Fragmentation is a result of two phenomena: waves from the borehole, damaging and cracking the rock, and gas pressure, widening those cracks and spreading out rock fragments. This model simulates the P wave escaping from boreholes and the cracks created by these P waves. It takes into account rock characteristics, provided by digital imaging, and explosive characteristics coming from VOD measurements. What we need to focus on, is the interaction of P waves coming from each borehole related to different timing sequences. This paper presents several simulations that show the influence of the timing and the sequence accuracy on the fragmentation distribution.

Jan 1, 2002

By Paul E. Thompson

Current magazine regulations are designed to avoid injury or property damage caused by accidental detonation as well as to store explosives securely. The primary emphasis appears to be the avoidance of unintended detonation or in the event such detonation occurs, the avoidance of damage to surrounding property. Adherence to these regulations largely serves the purpose intended but has caused difficulty in magazine sitting in built up areas. To the extent that magazine siting is too heavily restricted, other more significant dangers such as storage of explosives in more dangerous and less secure places may be encouraged. In summary, the regulations have served rural magazine locations well but may need further study for urban settings.

Jan 1, 1990