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By Roger N. Prescott

The Bureau of Alcohol, Tobacco and Firearms (BATF) is sponsoring legislation requiring the addition of identification taggants to commercial explosives. These are plastic particles with color coded layers that theoretically can be used to identify the explosive by date shift code.

Jan 1, 1980

By Alan R. Gadberry

Good mine planning is critical to the success of a safe, cost effective mine. Many factors contribute to the overall success of an open pit mining operation: proper pit location and development, good drilling and blasting practice, and well conceived short range and long range mining plans.

Jan 1, 1981

By Michael David Wilkins, Paul N. Worsey

Little research has been published on stemming blast holes, particularly what happens during the process. Previous work has concentrated on the performance of the inert material to find the best way to seal the hole and retain the explosive energy, at the exclusion of determining what happens during the loading and stemming process.

Jan 1, 1998

By John S. Manka

Of the various methods used to reduce the density of emulsion explosives prior to detonation; ammonium nitrate prill addition, glass micro-balloon addition and chemical gassing, chemical gassing is the method most often selected by emulsion explosive end users. Chemically gassing emulsions costs less than adding micro-balloons and chemically gassed emulsions have better water resistance than emulsions that add ammonium nitrate prills to reduce the bulk density. Unfortunately, the chemical gassing of emulsion explosives can be intricate and is often more art than a science. To gain a better understanding of chemical gassing, we investigated the factors that may affect the chemical gassing of emulsion explosives. Variables investigated as having an effect on gassing were the pH of the oxidizer phase, the amount and type of nitrogen in the emulsifier, the composition of the oxidizer phase, the use of pH buffers in the oxidizer phase, and how the gassing reagents are added to the emulsion.

Jan 1, 2004

By J Lyall Workman, Larry R. Fletcher

Blasting methods have been proposed for reclaiming abandoned underground coal mine sites having unstable conditions. The objective of blasting is twofold: the permanent stabilization of an area by the collapse of underground workings to prevent any future subsidence, and the use of blasting to close existing sinkholes.

Jan 1, 1991

By George Pittman, Dan McCutchen

When an explosive manufacturer in the USA wants to put a new explosive formula or detonator design in the toughest proving ground in North American, it is Florida. Florida conditions have baffled many creditable blasting experts. This paper deals with some of the methods used to overcome these problems.

Jan 1, 1995

By E E. Cloete, R I. McCrindle

Permitted explosives were previously nitroglycerine based and cap sensitive. Due to safety, health and environmental requirements, water-containing explosives, such as watergels and emulsions, were used instead. However, in order for these explosives to perform at their designed level during blasting, a more powerful stimulus than is delivered by detonators on their own is required.

Jan 1, 1999

By Jaime Huidobro, Michele Hall

The desensitization of an explosives column by the transmitted effects of the earlier detonations in nearby explosive charges is of vital concern to the explosives and blasting industries. Stress waves from detonations of borehole charges have the capacity to desensitize adjacent delayed borehole charges. This desensitization can be of a transient or a permanent nature.

Jan 1, 1994

By Thomas L. Barkley

This paper describes an unusual design for a 12 foot diameter, 30 foot deep circular shaft shot in a close in urban environment less than 100 feet from occupied structures. It uses diagrams, video footage, and vibration results to describe a 3 deck, 17 hole burn round used to pull 17 feet in one lift.

Jan 1, 1994

By Frank Sames

Blast vibration and airblast overpressure signals are generally rated and compared only by their maximum amplitude and the principal frequency associated with the peak pulse. The scaled distance concept is often used to predict peak amplitudes and can be applied for blasts in the same area of a mine to evaluate the statistical properties of a set of readings.

Jan 1, 1997

By R DeLon Hunsaker

In the past, quarrying and other small operations have not been able to take advantage of the lower cost, convenience and better performance of bulk slurries. However, with the introduction of repumpable emulsion slurries and their ability to be stored in containers as blasting agents, bulk slurries are now available for small operations with small diameter boreholes and are producing excellent results. This same concept is being used successfully in larger underground operations.

Jan 1, 1984

By Richard N. Snyder

In this system for connecting blasting caps to the initiation source, the need for a redundant design structure provides more reliable method of explosive initiation. This is accomplished by using a complete system starting at the blasting control, through the initiation line structure through the initiation line and connecting blocks to the blasting cap. The connecting structure between the initiation device and the blasting caps may be connecting blocks or other means.

Jan 1, 1995

By Shulin Nie

The dead-pressing phenomenon in emulsion explosives is wellknown. Research work on this subject has been carried out at the Swedish Detonic Research Foundation for the last few years. Several experiments with emulsion explosives under dynamic pressure condition have been carried out both in iron pipes and in blast holes in rock. The main object was to study the critical amplitude and duration of the pressure causing the explosive to be dead-pressed.

Jan 1, 1993

By Michael Swisdak, John Tatom

In a quantitative risk assessment (QRA), the ability to accurately model real-world situations is obviously critical. In the end, the model must be able to represent the effects produced by the detonation of the donor and the consequences on the target. The science that goes into such a model must be carefully thought-out and based on as much data as possible.

Jan 1, 2007

By Mike Cammack

Western South Dakota is predominately an agricultural area, with exception of the mining and timber industries in the Black Hills region. With precipitation rates averaging below fifteen inches per year, water is a precious commodity to the livestock industry. There is a constant demand for the construction of earthen water storage facilities (dugouts) to catch snow and rain runoff, or developing natural springs.

Jan 1, 1993

By D T. Froedge, Michael J. Nutting

A system consisting of an unlimited number of biaxial geophones that measure peak particle velocity and frequency has been developed and utilized at surface mines, quarries and construction sites. An ability to accurately measure ground vibrations completely surrounding a blast and to construct a vibration topograph has facilitated the study of blast design parameters and geologic factors on the resulting generation and propagation of the vibrations.

Jan 1, 1990

By Thomas E. Brown

With the ever increasing public sensitivity to our environment, the blasting industry can no longer be concerned with just drilling and blasting. Government regulations, augmented by public pressure, require that the industry must be more diligent in preventing spills, disposing of distressed products and packaging materials, controlling fumes and dust, preventing product contamination, developing environmental impact studies, and preventing unnecessary regulations. These liabilities in conjunction with those of vibration, air overpressure and flyrock will continue to greatly impact the industry.

Jan 1, 1995

By Yoshiharu Tanaka, Keita Morooka, Masaaki Yamamoto, Katsuhiko Kaneko

Smooth blasting is the standard method for underground rock excavation, to reduce over break and remaining rock damage. We already utilized the high accuracy of the electronic delay detonator to investigate its effect on over break remaining rock damage, and surface smoothness. And we presented at 11th annual symposium on Explosives and blasting Research.

Jan 1, 1998

By Hans Florin

This paper describes the modification of a nonelectric detonator which is ignited by a signal tubing. The heart of the new detonator lies in a so-called ignition transmitting element. The construction of the transmitting element is such that the detonator remains closed even after the signal tube has functioned. Due to the sealing of the delay element, this nonelectric detonator achieves the same accurate delay timing as high tech delay electric detonators and will not fail due to a sudden pressure loss.

Jan 1, 1988

By Dale Preece, Stephen Chung

Mining and quarrying industries recognize blasting as the most effective method for breaking and removing large volumes of rock. However, the economics of blasting are often offset by the costly trial-and-error approach. Researchers in the field of blasting therefore design models to help eliminate the number of trials before finding the best feasible solution. Because of the complexity of blasting, a capable model would allow the designer to look at more than one variable at a time so that the most critical factor can be tackled.

Jan 1, 2002