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By Kaby K. Kabongo

The paper is drawn from a project intended to explore a technique of prediction, control and optimization of fracture in coal induced by blasting. It evaluates the fines generated in coal submitted to dynamic loading stresses in an impact stamp mortar. The aim is to analyze a complex phenomenon of coal response to blast-generated stresses from a series of discrete simulations of shock and gas actions in controllable processes.

Jan 1, 1995

By D. K. Ingram, G. L. Mowrey, T. R. Rehak

This paper summarizes flyrock and blast area security fatalities from 1989 to 1999 and examines the causative factors. Coal and nonmetal mining used about 43 billion pounds of explosives and blasting agents between1989 to 1999. A majority of this consumption was used at surface mines. Accident data indicates that flyrock and lack of blast area security were the primary causes of blasting related injuries in surface mining. Fatal injuries due to lack of blast area security were attributed to: failure to clear blast area; failure to follow instructions; inadequate guarding; inadequate blasting shelter; and unsafe location.

Jan 1, 2002

By John Watson

Overview: Intro and Product Use Trends ?? Packaged Explosives ?? Bulk Explosives ?? Initiation Systems – Conventional Initiation Systems – Electronic Detonators ??Q&A

Jan 1, 2006

By Calvin J. Konya

There have been many different brands of high precision caps introduced on the US market in the last five years. High precision timing definitely effects the performance of the blast. One should be able to optimize fragmentation and minimize environmental effects with the use of high precision caps and selection of the proper time period. The consumer who purchases the caps may not be fully aware of the tolerances in firing times of caps used in the field. This paper will discuss results of field tests of cap tolerances from an independent study conducted by Precision Blasting Services.

Jan 1, 1989

By Terry Graf, Bill Thompson, John Guenther

SYNCRUDE CANADA LTD.. operates the largest synthetic crude oil production facility in the world. Over 60,000,000 Bank Cubic Metres of oil sand is mined each year from their open pit located in Fort McMurray, Alberta. Despite the extremely cold temperatures encountered during the winter months and the problems associated with frost buildup, SYNCRUDE has continued to operate on a 12 month per year basis. In 1989 SYNCRUDE mine management embarked on a comprehensive Frost Blasting program to improve mine production of their oil sand moving equipment. The following paper will discuss the development of their frost blasting program to its current status.

Jan 1, 1993

By J R. "Dick" Daniel

In the fall of 1988, The Cannon mine decided to investigate a central blasting system based on conventional electric blasting detonators being used to initiate rounds primed with Nonel detonators. The advantages of this hybrid detonator system were viewed as being safety and cost effectiveness. A study was done reviewing the safety aspects of utilizing a permanent blasting line installed throughout the main haulage drifts to a central blasting station located at the mine portal. The study addressed the following potential safety hazards: radio frequency induced current, stray current from both electrical utilities and transmission lines, galvanic and electrostatic sources of extraneous current.

Jan 1, 1989

By Michael S. Wieland

This report discusses the U.S. Bureau of Mines research regarding the desensitization and malfunction of cap-sensitive explosives deployed in underground coal mines. Delay blasting in underground coal generates severe shock waves and rifting forces that fracture and heave coal. These dynamic interactions can damage other charges still remaining in the delay pattern. The debilitating impacts precipitate degrees of reduced charge performance ranging from misfires to weak detonations or out-of-sequence firings. Damaged charges react poorly, perform less useful work, and/or generate atypical fumes with higher toxicity.

Jan 1, 1993

By Kenneth Eltschlager, Steven V. Crum, David E. Siskind

The Bureau of Mines was funded by the Office of Surface Mining (OSM) to determine how blast vibrations from a local surface coal mine were affecting homes in the towns of Daylight and McCutchanville, located in southwestern Indiana near Evansville. Although Daylight was about two miles from the blasting and McCutchanville four to five miles away, many residents claimed that blast vibrations were damaging their homes. At least one citizen felt that the vibrations worsened at the time the mine began cast blasting.

Jan 1, 1992

The breakage mechnism of a spherical charge greatly differs from that of the cylindrical charge used in underground mining. The advantages of the spherical charge could not be utilized until INCO Metals Company, Ontario Division, introduced large diameter holes to their operation.

Jan 1, 1978

By Jaki M. Wilson, Neville T. Moxon

The detonation pressure of ANFO can be significantly reduced by the addition of low density materials such as polystyrene, bagasse, sawdust or perlite. Laboratory and field test results have shown that homogeneous mixtures of these low density explosives can be produced in a bowl truck and loaded into a blasthole without segregation. The detonation pressure of the mixture can be altered to be more compatible with the material in which it is being used by varying the quantity of low density additive incorporated into the mixture. Field results have shown that these low density explosives can lead to significant cost savings without compromising fragmentation or production.

Jan 1, 1989

By Richard Scales, Giles Hellyer, Ian Travers, Dean French, Peter Bellairs

"The Mt Whaleback iron ore mine is located in the Hamersley Province situated about 1OOOkm to thenorth of Perth, the capital city of Western Australia. A small but significant portion of the waste in Mt Whaleback presents problems due to its ability to react with normal commercial bulk explosives resulting in premature detonations, two of which occurred at the mine in 1983 causing great consternation as well as disruption to the mining operation. The techniques and procedures developed to overcome this problem were based on the use of tough durable, acid and heat resistant liners to provide a physical barrier separating the explosive from the rock togetherwith the development of an accurate down the hole remote temperature logging technology. The liner technology was developed due to the inability to produce a reliable inhibited ANFO despite exhaustive mine based testwork."

Jan 1, 1999

By Tassilo Baur

Explosives are used in the entertainment industry in a wide variety of applications. Live performances such as automobile races, air shows and the like have incorporated the use of explosives into their programs. Even art work has been created employing explosive materials and techniques. The primary entertainment use of explosives, however, remains in motion pictures, television, theater and related fields where it comes under the auspices of special effects. Much of it falls roughly into the category of demolition, though the object being demolished may range from a cigarette in a person's mouth or clothing worn by actors to large objects such as automobiles, aircraft, or boats. This paper will attempt to provide an overview of the materials and methods by which these special effects are created as well as highlight the unique problems encountered in this field and their often equally unique solutions.

Jan 1, 1992

By Paul V. Sterk, James Wieser

Mining in underground situations requires constant change due to changing ore bodies and economics. The Homestake Mine in its 122 years of existence has gone through numerous changes due to these factors. Recent sustained low prices in gold and ore bodies that are smaller or within mined out areas have forced the mine to reevaluate how these ore blocks will be mined. This paper will describe the design, drilling, and blasting of a complex ore block using the blind raise uphole bulk mining method.

Jan 1, 1999

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 Everett Clausen, Richard Walker

CIL/EVANinc and the Canadian Explosives Research Laboratory of the Government of Canada have evolved a concept developed by Research Energy of Ohio, into a landmine neutralization system that is the most innovative to date.

Jan 1, 1999

By Chantale Doucet, Yves Lizotte, Alan Cameron

A joint Federal Government-Industry research project on the effect of geology on the fragmentation of rock excavated by blasting in underground developments was conducted at the CANMET Experimental Mine, near Val d’Or, Quebec. A total of thirteen (13) blasts were studied from November 1994 to February 1995. The analysis of each blast was divided into three stages: pre-blast characterization, including structural mapping, assessment of Rock Mass Ratings (RMR), Tunneling Quality Indices (Q), blast design documentation; blast characterization comprising blast vibration monitoring and analysis; and post-blast assessment comprising fragmentation assessment by digital photoanalysis, calculation of half cast factors and measurements of bootlegs.

Jan 1, 1996

By Christopher Smith

The critical nature of detonator function in blast design and its effects upon performance and safety of a blasting operation are well documented. Numerous laboratory and field studies have shown dynamic shock waves, generated by the detonating explosives in a shot, to be detrimental to the performance of the explosive columns in the adjacent boreholes. Laboratory tests conducted in Japan have explored the possible effects of dynamic precompression upon cartridges of emulsion explosives, which had been sensitized with different hotspot void producing methods. These tests uncovered significant differences in the magnitude of the dynamic shock wave pressures measured inside the different emulsion explosive cartridges, and demonstrated these pressure differences by crushing detonator shells inserted inside the emulsion cartridge. Basically, the results of these tests clearly showed the magnitude of the compressive force applied to the detonator inside the primed explosive cartridge to be a function of the mechanism that had been used to sensitize the emulsion (i.e., glass microspheres, plastic spheres, chemical gassing). The current study was designed to further explore the actual detonator failure mechanism in these dynamic precompression tests using live detonators inside the emulsion cartridge as opposed to empty detonator shells. The testing involved inserting commercial delay detonators inside emulsion charges, which had been sensitized with common hotspot void producing agents, and subjecting the primed explosive cartridge to the dynamic pressure wave generated by an underwater donor explosive charge. The effects of variations in the emulsion’s sensitization method upon the damage inflicted to the detonator were studied. Depending upon the degree of detonator damage, detonator crushing can lead to varying degrees of detonator malfunctions, ranging from sympathetic initiation of the detonator, to a reduction in delay time accuracy, to reduced detonator output, to complete detonator failure. Each of these malfunctions can have serious detrimental effects upon the performance and safety of a blasting operation.

Jan 1, 2006

Jan 1, 2002

By Claude Cunningham

AEL’s Electronic Delay Detonators are in routine use and growing in both volume and breadth of application in Africa. This trend will continue and grow internationally owing to increasing pressure on rockbreaking operations to conform to sustainable development principles. A fundamental breakthrough has been achieved, bringing production blasting into line with technologies, which leverage performance through tight monitoring and control. When moving from pyrotechnic systems, benefits are normally realized without having to adopt different timing patterns, but significant additional benefits are realisable by using the flexibility and precision of the electronic units to enter windows of timing previously closed. The higher price and increased care needed are a worthwhile investment, enabling operations to cross the chasm to stronger revenues, but the system must be robust and suited to the application and personnel. Economic models are vital for keeping track of the potential and achieved benefits of these systems. Some resistance can be expected from those who stand to lose income as a result of the improved efficiencies.

Jan 1, 2004