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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 Robert Hopler

In the annual report under the Explosives Act for 1905, H.M.inspectors state that over 90 percent of the accidents causing death or personal injury occurred in the use of explosives and under miscellaneous conditions to which the controlling provisions of the Act do not apply, and that such accidents caused 43 out of the 50 deaths, and 312 out of 348 cases of injury. The number of accidents grouped under the heading of “Use and Miscellaneous” is less than that for 1904 - viz., 281 against 301. By these accidents 43 persons were killed and 312 injured, as compared with 39 killed and 343 injured in 1904

Jan 1, 2007

By Cceliksirt, V Erkan

This computer program has been developed under the field conditions for use in control of surface drilling-blasting operations. This paper outlines the relevance of fragmentation to quarrying, open pit mining or road cutting and key features and operating principles of the software (DelPat for Windows 95).

Jan 1, 1998

By R. Farnfield, W. Birch

Arguably, some of the most restrictive statutory blast vibration requirements attached to mineral extraction operations can be found in the United Kingdom. Such limitations are, as a rule for the UK, stipulated together with a required statistical confidence that has to be observed in the blast design process in order to ensure total planning compliance. A key element in this procedure is the effect imparted by vibration data scatter from previous blasts as this becomes reflected in the site’s operational standard error statistic and in turn directly influences the maximum instantaneous charge weights that can be justifiably employed. The greater the scatter, the lower the compliant charge weights become.

Jan 1, 2006

By Tom Short

"Construction blasting covers a very extensive variety of explosive applications. I will discussseveral of these with you and then show slides from my collection, starting in 1956, which will betterillustrate the types of blasting under discussion."

Jan 1, 1991

By Lars Arne Granlund

Due to the coarse structure of mining explosives, one has to model a finite reaction zone,contrary to C-J calculations, describing their detonations, i.e they become dependent of diameter and confinement, An effort within the DYNO group has been to investigate if the DSD theory ( originally developed by Bdzil, Stewart / Los Alamos ) can be used to describe major groups of civil explosives.The groups of explosives tested are dynamite, anfo, aluminised emulsion, heavy anfo and straight emulsions.

Jan 1, 1995

By Tony A. Rorke, Joe R. Brinkmann

The application of instrumentation to better understand and improve production blasting is one of the most fruitful areas of explosives and blasting research. The majority of instrumented studies of production blasting have relied on the extrapolation of far field measurements to postulate blast performance in regions of interest closer to the charge where rock breaking takes place. However, the nonlinear and dissipative nature of the quantities being measured raises serious questions as to the accuracy and validity of such extrapolations.

Jan 1, 1991

By George D. Raitt

Anyone who has spent any time in and around the drilling and blasting profession knows that probably the most critical part is the drilling portion. A blasthole is nothing more than a cylindrical vehicle designed and strategically situated to hold and contain an explosive charge so that it can be detonated in the most efficient and optimum manner possible. It matters very little if the latest “State-of-the-Art” explosive or detonation system Is employed if the hole is poorly placed; i.e. excessive burden and spacing, sized incorrectly for desired results, insufficient in depth etc.. This is not to mention that the drilling phase is the most expensive, requiring sizeable initial outlays and upkeep. It’s also true that improper drilling can cause costs to skyrocket throughout the remainder of the work cycles such as excavating and hauling, crushing, screening and so on.

Jan 1, 1990

By Michael Wieland

For shooting rock properly, some relatively fixed quantity of rock work is required from the total charge mass, while keeping the overall toxic fumes to a minimum. The overall fumes weighted for the toxicity of different species and taken per unit charge mass, ??, are represented by a relative fume toxicity (RFT) formula. The worst two contributions are often carbon monoxide {CO} and total nitrogen oxides {NOX}, so the traditional Russian formula RFT-R formula suffices, though a generalized form RFT-G with more terms is worth checking. Using the work-principle model from thermodynamics, the rock work per unit charge mass, ??, is found from the reduction in internal energy for the reaction zone. This resolution technique for rock-work invokes the usual assumption that the quick irreversible process occurs without notable heat transfer to the rock (adiabatic); rock-work is not resolved, when this restriction is untenable. The ratio of ?? to ?? yields the weighted toxic fumes divided by the rock work or the readjusted fume toxicity ??, where ?? = ??/??. For convenience, graphical trends of ??, ?? and ?? were normalized using reference results for a stoichiometric (ANFO) mixture of ammonium nitrate (AN) and fuel oil (FO) shot under nominal rock confinement, noted later.

Jan 1, 2006

By Z X. Zhang

Ground vibrations from the blasts of the LKAB mine at the Malmberget town had reached 18-19 mm/s from year 2000 to 2002. From 2004 to 2010 the maximum vibrations had been reduced to 9 mm/s and most vibrations lowered to about 5 mm/s, indicating that the technical measures used in the mine are effective in vibration control. The major measure that has always been used in Malmberget mine is the method called Changing Initiation Sequence (CIS in short). Another method named Dividing Ring Blasting (DRB in short) is often applied to some special blast rings in the mine. Both methods have been proved to be successful in vibration reduction, and they do not need any additional costs. Because of the two methods, both maximum vibrations and average ones have been reduced by around 50% since 2004.

Jan 1, 2012

By Paul Kunze

For some of us, the most disagreeable part of being the blaster- in - charge is doing the required paperwork. Cost coding on time cards, drilling reports, magazine inventory logs, and blast records all eat into our time. When all goes well, which I suppose is 98% of the time, the blast records are submitted and filed, probably never to be seen again. Sometimes a progressive operation will use the information documented in the blast reports to evaluate blasting effectiveness and improve results. When the report is consistently used in this fashion, costs can be reduced and other efficiencies will be realized. A blast report in times past was a simple form that mainly was used to keep track of the drill footage and of the powder used in the shot. However, as the population and consequences of careless blasting increase, multiple levels of blast documentation are now being required nearly everywhere, during all phases of the drill and blast process. We are now compelled to create preliminary blast designs prior to commencing work. We are required to submit pre-blast plans before each shot, and we need to generate post-blast reports that document the details and results of each shot.

Jan 1, 2004

By David Cole, Paul Cooper, Dale Preece, Jerome Stofleth

The Explosive Destruction System (EDS) has been designed at Sandia National Laboratories for the disposal of chemical munitions (phosgene, mustard gas, sarin etc.), many dating back to World War I. EDS is a portable system that is trailer mounted and consists of a vessel into which a chemical munition can be loaded and opened for neutralization with linear and conical shaped charges. Gases are contained within the sealed chamber. The linear shaped charges split the munition in two and the conical shaped charge (CSC) is aimed at the explosive burster, in each munition, which is detonated by the resulting shaped charge jet, Toxic chemicals remaining in the vessel following detonation are neutralized and disposed of. This paper documents the development of a new CSC needed to reliably detonate explosive bursters in an expanding array of chemical munitions that are beyond what the EDS device was originally designed to eutralize. Design of this new CSC was controlled by the need to deliver energy above the detonation threshold into the explosive after penetrating the outer steel casing, fluid, the burster casing and finally the explosive. Design considerations were driven by jet conditions at the steel/explosive interface inside the burster. Parameters to consider in CSC design include: 1) diameter, 2) liner thickness, 3) liner position in body, 4) explosive weight, and 5) liner shape or interior (apex) angle. The effects of these parameters on final CSC performance are examined in detail. CSC’s that meet the design specifications have been manufactured and tested. The performance of these charges are compared with the original design requirements.

Jan 1, 2002

By Don Novotny, Dana Spencer

In this workshop our intent is quite simple; that is that we will introduce a relatively new technology that may have applications in blasting applications. This technology is the laser initiation of explosives. This workshop course is not intended to suggest ways in which specific blasting problems can be resolved. That is the purview of experts within each of your fields.

Jan 1, 1994

By Yang Jun, Qu Mei, Zheng Yao-wu, Chi Li-yuan

Due to the necessity of the prediction of blasting seismic effect around strip mine bench blasting area, the paper provides a method to predict the blasting seismic effect by employing the superposition of seed waveform at different monitoring points. The method assumes that blasting vibration waveform per hole is similar to seed waveform at monitoring point. Therefore seismic wave consists of the superposition of the waves from all of blast holes. Firstly, via sensors multiple seed waveforms can be achieved at different distances from signature hole. Then, by using the given dose and the distance, the vibration waveform of a certain blast hole can be calculated by the corresponding seed waveforms. Finally, the initiation delay time interval per hole is added to the propagation time to the predicting point. The predictive waveform at the whole blasting area can be obtained by superimposing all of the single waveforms. Considering the vibration waveform of a single blast hole changes greatly with the distance, under different distances condition the seed wave employed to superimpose is achieved from the similar distance. The experiments demonstrate that based on the method the predictive vibration waveform and spectrum are basically consistent with monitoring results around near-field blast. Compared with single seed wave method, the superposition method of multiple seed wave is more reliable to predict the duration of blasting vibration, the peak particle velocity, dominant frequency and frequency distribution.

Jan 1, 2015

By Christopher Cloete Uys, Luis Manuel Poinha Valentim

The purpose of this workshop is to describe and demonstrate the use of SPEEDWAVE, a high speed data recorder, its VOD enhancements, and the software which binds the system together. The system was designed by TLC Sohware, SOUTH AFRICA. TLC is a company spedalising in the solution of engineering problems, using computertechnology as a base. TLC was founded in 1987, and has since been involved in many different.measurement, control, simulation and modelling projects. Wth respect to the blasting industry, TLC has, in conjunction with AECI South Africa/ICI, developed a tunnel mining design aid, a ring blasting design aid, a multkhannel seismograph and a laser surveying program. In 1989, TLC designed and built the BA800. a microcomputer-based high speed recorder. These recorders are still in use and are producing valuable results. Based on improved technology and with the field experience of the BA800, TLC has designed and developed the data recorder SPEEDWWE.

Jan 1, 1995

By O E. Jr Crenwelge

Frequency domain, single-charge vibration signatures are used to interpret the characteristics of explosive impulse excitation and ground vibration transmission. The effects of charge height, charge splitting, and different blasting agents are first discussed. Then the effects of rate of change with distance of overburden material properties and layer or surface geometries are illustrated.

Jan 1, 1988

By Randy Wheeler

The importance of having full wave form information for recorded blast events cannot be overstated. Knowing the peak particle velocity and the frequency at the peak are the tip of the iceberg. This presentation will focus primarily on using the FFT (fast Fourier transform) for detailed frequency analysis. Employing linear superposition to evaluate timing effects on amplitude and frequency will be discussed.

Jan 1, 2005

By W. J. Birch, A. Wetherelt

The scaled-distance model for blast vibration analysis is the standard method employed throughout the surface mining and quarrying industries to model Peak Particle Velocity (PPV) data. Although empirical, the method is widely accepted and through the simplicity of its application and ease of graphical verification is set to remain a popular option. The validity of the technique relies principally on the fundamental parametric assumption that blasting data is normally distributed. Throughout the evolution of scaled-distance modelling, this is an issue that has most often been presumed rather than proven (most likely due to the tediousness of the calculations involved). In the few cases when normality has been given some degree of consideration, the result has been the product of a simple visual inspection of frequency distributions: clearly unsatisfactory. However recently the soundness of this assumption has been brought into question, with obvious connotations for blast modelling in general. This paper considers this fundamental issue and seeks to investigate the normality hypothesis within the blasting context through an in-depth statistical analysis of what possibly can be described as an ‘ideal’ blasting dataset. This being a rare case study concerning an opencast coal site in England, where for the entire life of the site every single blast was monitored and recorded through the use of permanent monitoring stations. This has provided a unique ‘total population’ dataset of considerable size from which the assumptions of normality are put to the test.

Jan 1, 2005

By John Vynne

Too often, a mine’s operations, including drilling, blasting, loading, hauling, crushing, processing, etc., are considered independent steps, rather then a continuous process. In fact, these are interdependent operations with each step in the process having an impact on subsequent operations. If the effectiveness of the drilling and blasting operations can be improved, they will impact the entire mining process. Some of the resulting improvements include: level benches on grade; fragmentation and diggability with the result being reduced loading times; haul cycles improvements; and the crushing and milling operations will be more efficient and less energy consumed. Thunderbird refers to this as “Drill to Mill” information cycle or process. This paper focuses on two of the technological enhancements Thunderbird has added to its drill monitors that allow the mines to impact the “Drill to Mill” concept. These enhancements are: incorporating global positioning satellites into drill monitors; and radio off-loading of data.

Jan 1, 2001

By Michael F. Barber

"Highway slopes are intended to remain stable over a long period of time. Unexpected slope failures can be costly in terms of human life and property damage or loss. Cleanup of failures can prove to beextremely expensive."

Jan 1, 1999