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By James Rowland, Marcia Harris, Richard Mainiero, Michael Sapko

All explosive materials produce a cloud of reaction products, the most toxic of which is nitrogen dioxide (NO2). In the study reported here, 4.5-kg (10-lb) charges of blasting agent confined in either thin-wall 10-cm (4-in) diameter galvanized pipe or 10-cm (4-in) schedule 80 seamless steel pipe were detonated in a closed chamber. The detonation gases were analyzed for NO2, nitric oxide (NO), ammonia (NH3), hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and methane (CH4). Data were evaluated to determine the kinetics of the oxidation of NO to NO2. Analysis revealed that the only mechanism for NO loss for the conditions existing in the chamber was the reaction 2NO + O2 6 2 NO2. The rate constant was 2.08 ?? 10-38 cm6 molecules-2 sec-1 for the rate equation -??d [NO]/dt = K ?? [NO]2 ?? [O2] for NO concentrations up to 100 ppm. The rate constant is in agreement with that recommended by Baulch, Drysdale, and Horne (1973).

Jan 1, 2006

By Stig O. Olofsson

The problem of overbreak in underground construction and mining is normally approached by a variety of smooth blasting methods. Numerous small diameter, low velocity explosives have been developed specifically for blasting the contour line. Increased mechanization in rock excavation has led to the development of several methods of mechanical explosive loading. A new mechanically loaded smooth blasting explosive was developed in Sweden . However, several limitations were realised, which after several trials resulted in a hybrid smooth blasting method, The Suaer Cautious Contour Blasting Method which will be discussed in this paper.

Jan 1, 1994

By Douglas Bartley, Robert McClure

This paper discusses the advances in programmable, testable high accuracy electronic detonator technology. The operation and safety of electronic detonator systems are required to meet rigid safety standards and withstand the demanding environment of in-field applications. These requirements are discussed through comments on existing safety requirements in Europe.

Jan 1, 2000

By Lex L. Udy

Properties of an explosive which itiuence its performance on rock breakage are analyzed in relation to the rock: hardness and a discussion on the interaction of an explosive with the rock during the blasting process is given. Theoretical concepts regarding ideal and non-ideal detonation are reviewed to explain how the physical and chemical factors of an explosive influence the rate of energy release and its consequence on blasting performance. While a lower velocity of detonation indicates a slowed chemical reaction it does not necessarily mean a loss in energy from the explosive. High density ammonium nitrate (HDAN) can be used effectively in the formulation of modern industrial explosives to slow the energy release rate with its attendant decrease in detonation velocity. Examples of blasting performance using custom formulated explosives with HDAN are presented.

Jan 1, 1995

By P D. Katsabanis

According to Persson(1) steady state detonation along a cylindrical charge can be regarded as a self propagating process in which the axial compressive effect of the shock front discontinuity changes the state of the explosive so that exothermic reaction sets in with the requisite velocity.

Jan 1, 1989

By Xiaoning Yang, C David Pearson, Brian W. Stump

An experimental study of ground motion from explosions designed to remove overburden in an open pit coal mine is reported. The purpose of this study is a characterization of these ground motions in the distance range of several tens of meters to several kilometers. The investigation has focused upon both single cylindrical sources with different explosive configurations as well as arrays of charges in the production mode. Critical to this study of source configuration and coupling is experimental control of the individual explosions, the timing of the explosions and the geological properties. The height of the explosive charges, their depth and charge distribution were monitored in the field. High speed photography as well as velocity of detonation measurements were made on the multiple explosion source so that detonation of individual charges could be documented.

Jan 1, 1994

By D P. Yang, Yang R. G

The laws of throwing and heaping of engineering blast are important for making use of throwing and heaping of thrown body to form certain shape, such as building dams by directional blast. The article is to apply Ballistic theory of single thrown body to take the throwing course of thrown body as the movement of particle system, and then delimit the total of thrown body into units of thrown bodies, and regard the heaping shape of single thrown body as a perfect triangle, and found a quantitative relation between macro-geometry parameters of perfect triangle and designed parameters of explosives. The theory has been adopted in blast practice and gotten good effects.

Jan 1, 1999

By Robert Morgan

With improved methods for designing and detonating shots the potential for flyrock can be significantly decreased, but there are few absolutes in blasting; therefore blasters must learn from the mistakes of others. Blasters must conscientiously employ control measures to minimize the risk of flyrock. The worst case incidents which tend to be widely reported by the media, should serve as a reminder to us all that minimizing the risk of flyrock must be incorporated into the design of the drill pattern and blast design.

Jan 1, 2001

By J Lyall Workman, Peter N. Calder

"Large hole rotary drilling is one of the most common methods of producing blastholes in open pitmining. Large hole drilling generally refers to diameters from 9 to 17 inch (229 to 432 mm), however aconsiderable amount of rotary drilling is done in diameters from. 6% to 9 inch (165 to 229 mm). Thesesmaller diameters are especially prevalent in gold mining and quarrying."

Jan 1, 1996

By Ronald L. Cocklin, Vivian Patz

Blasting techniques are becoming increasingly sophisticated as the need for improving mining efficiency grows. One of the areas of blasting that has never been fully exploited, due to a lack of a control and reliability, is the initiation of explosives. Expert Explosives have taken on the challenge to not only provide an initiation system that offers control and reliability, but also provide benefits that are critical to enhanced mining productivity. These benefits can only be delivered through the medium of electronics and computer controlled systems.

Jan 1, 1995

By N/A N/A

Aw a rd winners from the University of MissouriRolla. Back row from left: Seok Bin Lim, Chris B o l l i n g e r, Adam Kre s l e r, Scott Geer, Joseph Cohn, and James (Buck) Hawkins; Front ro w f rom left: Dr. Worsey, Trish Robertson, and Fio G i a n a

Jan 1, 2004

By Zach Ellis, Dusty Fisher

Lightning is a major concern in the explosives industry. The enormous amount of energy delivered to the Earth from a single bolt of lightning is more than capable of detonating explosives. Although explosives incidents caused by lightning strikes are rare, lightning is of great concern to blasting professionals who spend many hours working on or near loaded blast patterns.

Jan 1, 2015

By Robert Benedetti

This paper describes various mitigation methods in order to reduce the maximum acceleration of the floorboard of hulled vehicles when explosive charges buried in water saturated sand were detonated beneath them. The effects on floorboard acceleration of adding a vehicle hull, several types of floorboard bracing, the use of foam to fill the gap between the floorboard and hull, and the use of foam to isolate the floorboard from the hull have been investigated. Small scale testing was conducted, which used bar magnet velocity gages to measure the velocity as a function of time of the center of the floorboard, directly over the charge, where the acceleration was expected to be greatest.

Jan 1, 2012

By John Haviland, Richard E. Danell

"BHP Australia Coat Pty Ltd (BHPAC) operates seven large open pit coal mines in the Bowen Basin ofCentral Queensland, Australia. These mines have operated for periods ranging from 16 to 37 years. All of these mines have dipping seams to varying degrees and are facing increasing overburden removal in an effort to maintain production. To ensure the economic viability of the operations, this increased level of overburden removal must ah.0 be conducted at lower unit costs."

Jan 1, 1995

By Narendra Gupta, Gaurav Srivastava, Abhinav Sharma

From the days when plain detonators and safety fuse were used for initiation of commercial explosives, the commercial blasting and mining industries have made rapid strides. With the advent of electronic detonators in the late ‘90s, the face of commercial blasting was changed forever. The Mining Industry in India initially took a while to embrace Electronic Blasting Systems (EBS), however, more recently the industry has taken to EBS in a big way.

Jan 1, 2015

By Mike Lovitt

New Gold Inc. had commissioned Orica to assist with the design of the drawbell blasting at New Afton Underground copper/gold block cave at Kamloops, British Columbia, Canada. Orica have had much success in developing the single-shot drawbell method at Freeport Indonesia in 2001 in the Deep Ore Zone and they will be using it exclusively in their new Grasberg Underground Operation. RioTinto Northparkes have also used the single shot drawbell blasting in their Second Lift E26 Project and even in the E48 orebody which is a post undercut block cave, realising the safety and operational benefits of this blasting method.

Jan 1, 2013

By Brian W. Stump

"Seismic waves from explosions can be used to characterize physical processes in and around the source. The quantification of absolute levels of ground motion is important for minimizing impact on nearby people and structures. We contrast work in characterizing seismic radiation from contained nuclear explosions with ground motions from multiple explosion quarry blasts. A physical basedunderstanding of the explosion source function allows prediction and extrapolation to new environments where experimental data may not exist."

Jan 1, 1990

The underwater test method for the determination of energy content of explosives is a very useful method. It’s also the only one which can separate shock and gas heave energies from each other. The total energy can be determined as a sum of these partial energies. Because of this special feature, the test method can be used to develop the energy content of explosives for different purposes; the military high explosives should contain more shock energy whereas the gas heave energy is a very important feature for the blasting explosives. The goal of this study was to find out the effects of aluminium and sodium perchlorate increments to the shock, gas heave and total energy values of an emulsion explosive and detect the particle size effects of two different aluminium powders to the total and partial energies as well. Both partial energies as well as the total energy were observed to increase linearly as a function of aluminium (A-80) concentration. The fine aluminium powder (A-100) (6%) also seemed to increase the shock energy of the explosive slightly whereas the gas heave energy was observed to remain unchanged to compared to the normally aluminazed (A-80) (6%) emulsion explosive. Therefore the fine aluminium powder also increased the total energy, but only very silightly. The fine aluminium powder can probably take apart to the chemical reactions more easily during the detonation. (3%) of sodium perchlorate (NaClO4) mixed with (6%) of (A-80) aluminium powdered emulsion explosive was observed to effect to the gas heave energy content of the explosive, but only very slightly. The shock energy was observed to remain unchanged.

Jan 1, 2005

By Jack Elorenta

We often hear that, "Blasting was an art, but now blasting is now a science". 'Scientific' blasting implies that we have quantified and reproducible measurements of the feedstock and product of the blasting process. However, the industry's reluctance to adopt two key technologies, drill monitoring and optical size analyzers, sheds doubt on the claims of scientific blasting.

Jan 1, 2003

By Dennis E. Mitchell

The need to develop and field explosive, pyrotechnic and propellant initiating systems that have high reliability and extraordinary safety requirements has led to the exploration and development of several materials and initiation systems at our laboratories. Our approach to initiating device development encompasses five main areas; energetic materials development , device physics, theoretical analysis and model development and experimental verifications

Jan 1, 1995