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By William Clark, Rick Taylor

"Ajax Contracting was awarded the project to drill, blast and crush 100,000 tons of quarryrock for the Forest Service In Elk City, Idaho, during the summer of 1992. This projecttakes place in an area where environmental groups opposing any development in NorthernIdaho forced the Forest Service to look for road rock In any place they could get it. Theresult was that a quarry could not be developed. It was decided that rock would be takenfrom a road cut (under the guise of straightening the road) on the main artery of Elk City,Idaho making the drilling and blasting a very sensitive issue to the local truckers haulingtrees and lumber to and from a mill."

Jan 1, 1993

By Donald H. Matthews

I wish to preface my remarks with the warning that I, in no way profess to be an authority on the U. S. Department of Transportation, Hazardous Materials Regulations, 49CFR Parts 100-199, nor attempt to advise any one on the regulations or how they should conduct their business in relation to the regulations. I merely wish to convey my interpretations of the regulations and some of the procedures adopted by my company to comply with these regulations, with the hope that this information may help others to better understand the regulations and help them formulate their own procedures for compliance. I will cover nine problem areas and furnish sources of information for anyone concerned with explosives transportation.

Jan 1, 1977

By Mark S. Stagg, David E. Siskind

Five major environmental effects of rock blasting are ground vibrations, airblast, flyrock, dust and fumes. What makes them "environmental" as opposed to occupational health and safety issues is that their impacts are felt off the mine, quarry or construction site. For some impacts, safe zones are defined through experience, flyrock being a good example. Flyrock at a mine can be 1) rock thrown beyond the blast area or expected hazard zone, 2) rock thrown beyond the permit area, or 3) rock thrown more than 1/2 the distance to the nearest non-mine structure (OSM rule for surface coal mines). Rock throw of less than the "flyrock" range is then a safety issue.

Jan 1, 1997

By Vilem Petr

Optimization blast design parameters for rounds used at surface mines, quarries or cast blast has taken on a new importance with the increased the cost of the explosives and electronic detonators. This paper addresses the fundamentals of blast design and optimization explosive energy utilized for fragmentation. This laboratory studies shows that one key variable-the strain energy set up in rock mass by blast vibration – can be used to predict the extent of damage done to the rock strata, the degree of fragmentation of the broken rock, and the velocity of the broken rock. It also shows how the dynamic strength of the rock strata is influence the fragmentation size distribution as well as the blastability.

Jan 1, 2008

By H Fukui, K Ichikawa, K Aikou, E Suzuki

An electronic delay detonator (EDD) consisting of a digital-base electronic delay module and a conventional instantaneous detonator module, designed for series connections with a special adjustable-output blasting machine, is described and shown to provide a delay time accuracy some four to twelve times higher than that of pyrotechnic millisecond and decisecond delay detonators, together with the other performance characteristics necessary for practical use. Also described is a blasting design system which allows effective reduction of ground and air vibration, through the use of EDDs with optimum delay times as determined by accurate computer simulation based on wave form and other data obtained from an on-site single-shot test blast.

Jan 1, 1989

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 C De La Cruz

The use of a thin-film piezoelectric stress gauge to determine the pressure profile in a detonating explosive has been demonstrated. These PVDF gauges have measured, in the borehole, the Chapman-Jouget pressure and the release adiabat of the detonation products for several explosives including ANFO and ANFO/emulsion mixtures. The technique can provide: (1) a direct measure of the blasting stimulus, (2) a sensitive QA tool for the blaster, and (3) a means to examine the magnitude and effects of preshock from adjacent bore holes. The PVDF pressure gauge is self powered, can measure pressure from a few bars to 400 kbars, has high time resolution (0.05 µsec), and is easy and economical to use.

Jan 1, 1997

By Sean Paterson

The purpose of this paper is to demonstrate a method of delaying and loading a shot. Since entering the construction industry, I have learned that cover is needed on a lot of blasts. When in close having to cover shots was new to me and it seemed time consuming and wastefull. Until I really needed it and didn’t have it. So What To Do??? Remember that safety comes first, if you have concerns cover it. Even if you have to sit on your shot all night to wait for cover. This method is not a replacement for cover, but it will help keep your rock down. Do not bet your life, others lives or your career on it.

Jan 1, 2001

By John Brennan

The Avalauncher has been an integral tool for avalanche mitigation work for close to 50 years. With their ability to place a kilogram of high explosives up to two thousand meters away, they routinely serve as a short range alternative to military artillery. The Avalauncher’s roots can be traced to a pneumatic baseball pitching machine used by Major League Baseball teams in the United States in the late 1950s. Throughout the decades, many modifications have been made to both the launcher and its projectiles. Current technology has allowed the Avalauncher to attain greater accuracies and operational range. In this paper I plan to cover not only the history of the Avalauncher but also explore its potential future.

Jan 1, 2009

By Randall M. Wheeler, Kenneth K. Eltschlager

Blasting Seismographs use microphones to measure air overpressure from blasting. The microphone height above the ground has been the object of some controversy. The current ISEE “Field Practice Guidelines for Blasting Seismographs” specify microphone placement within 1.2 inches of the ground or over 3 feet above the ground. In this study, air overpressure measurements were taken at different height intervals and compared. Blasting seismographs constructed to the ISEE “Performance Standards for Blasting Seismographs” were used to monitor construction, quarry, and coal mine blasting. Near and far field measurements were taken to obtain representative spectral and amplitude ranges. The comparative analysis shows that microphone height has negligible impact on air overpressure measurements.1

Jan 1, 2005

By John Watson

The earliest known records related to mining document in dramatic terms the fact that mining methods have undergone significant change over the centuries. Wooden wedges, hammers and chisels, “fne setting”, to name a few, were the frst tools used to extract ore .or quarry rock for civilization. These inefficient tools and unsafe practices have been replaced today with some of the highest technology known to man. At the heart of most mining operations is the blasting program which utilizes one of the most efficient tools ever invented.. . explosives. Ever since they were invented, miners have been searching for more efficient products and methods with which to harness this “tool” and make it safer, reliable, and more eficient to use.

Jan 1, 1997

By Stanley Griff, William Herrera, William O. Seals

"The Navy initiated liquid propellant research in the early 1940's. The first promising Navy liquid propellant, Otto Fuel II, was developd in the early 1950 as a potential torpedo fuel. Later, the Navy developed a HAN based liquid propellant designated NOS-365, a hydroxylammonium nitrate, isopropylammonium nitrate and water formulation. A large gas volume generated by this propellant produced a large wake behind the torpedo. As one can readily understand, this negated the useof the propellant for this application. Recognizing the large gas volume as a desirable propulsion system for guns, the Navy embarked upon a gun propellant proqam. Utilizing a bulk loaded gun sysytem, the program failed when the gun was destroyed by the propellant detonating."

Jan 1, 1990

By Advanced Initiation Systems Inc

10 years in R&D Last 5 years available commercially Worldwide Met strict approvals for manufacturing and use

Jan 1, 2004

By Romel Villanueva, Juan Vasquez

We present the results of our field research on the variation of the density of the gassed explosives and their influence on the blasting results in the Peruvian mines: Yanacocha, Toquepala and Antamina. Currently, 90% of Peruvian mines uses gassed explosives, for their economic and technical benefits. But new practices and design criteria have had to be adopted, and the most important a careful control of the in-hole density, whose variation in the depth of the hole strongly affects the detonation process. For gassed explosives the density varies gradually according to the depth in the hole, due to the pressure on the bubbles by its own weight. The density at the bottom of the hole can reach critical values, which directly affects the start of the detonation in the booster zone with a high probability of nitrous fumes formation. On the other hand, density translates into the amount of explosive and energy available. Therefore, for the optimum performance of the explosive, the minimum and maximum values of the in-hole density must be determined. For the cases studied, the maximum in-hole density and the maximum charge length have been determined. When the charge length is greater than 7.0 m [ 23 ft.] special care must be taken with the cup density, which as a general rule should not exceed the value of 1.15 g/cm3 [71.8 lb/ft3] at the risk of losing the sensitivity at the bottom, also increasing the probability of nitrous fumes, bad fragmentation and finding intact explosive after blasting. In the large holes in Toquepala and Antamina mines, where the charge length can be greater than 9.0 m [29.53 ft]. If the cup density is greater than 1.15 g/cm3 [71.8 lb/ft3] the in-hole density can easily reach a high value of 1.30 g/cm3 [81.16 lb/ft3].

By Fumihiko Sumiya, Yukio Kato, Yoshikazu Hirosaki

Secluential blasting is one of the most popular methods in blasting. tiowever, it is well known that an emulsion explosive can be dead-pressed by dynamic pressure generated by the previous detonation. It is difficult to gain the expected blasting performance due to tb.e malfunction of explosive caused by deadpressing and shock desensitization. Such malfunction of an explosive is undesirable for safety blasting operation. Voids in the emulsion explosives will considerably affect the performance of explosives such as sensitivity, detonation velocity (DV), pressure-resistance and so on. To clarify the detonability and the performance of precompressed emulsion explosives, the DV was measured. Three types of microballoon or micro bubble ; two types of glass microballoon(GMB), resin microballoon@MB) and chemical gas bubble ; were used as sensitizers for the sample emulsion expiosives. The underwater explosion test was carried out to load dynamic pressure into the sample explosives. The dynamic pressure was generated by the detonation of a donor explosive, and the DV of the sample explosives as acceptor was measured by ionized gap terminals. The dynamic pressure level and initiation interval for the donor and the acceptor were chosen as experimental factors. The detonability was carefully investigated at short initiation intervals taking into consideration the interaction between same delays caused by the deviation of the ignition time of the electric detonators. From these experiments, the following results were obtained ; A) The DV of precompressed emulsion explosives was low compared with that of uncompressed emulsion explosives in all pressure conditions. B) The decrease of DV in the sample explosives sensitized by GMB s was larger than that of DV in the sample explosives sensitized by RMBs or chemical gas bubbles. C) The recovery of the detonability occurred rapidly in the sample explosives sensitized by RMBs and chemical gas bubbles. However, a long period was needed for the recovery of detonability in the sample explosives sensitized by GME! s. It was concluded that the type of microballoon and micro bubble significantly influenced the detonability of precompressed emulsion explosives.

Jan 1, 2002

By Tom Snyder, John Brulia

PART 3 – UN Identifi cation Markings for the Highway Transportation in Commerce of Bulk Explosives, Oxidizers, and Combustible Liquids

Jan 1, 2015

By Ajoy Singh

A study was conducted to investigate the damage potential to underground multi-seam openings caused due to vibration generated by open-pit coal mine blasting. The objective was to recommend optimal explosives weight per delay to be detonated in open-pit blasts to ensure the safety and stability of underground openings. Sixteen blasts with varying charge weights and initiation sequences were conducted at Samleshawari open-pit mine and eighty four blast vibration data were recorded in the Hingir Rampur underground colliery in India. Analysis of vibration data showed that roof of the underground openings vibrated with higher amplitude of vibration compared to pillars and floors. The amplifications of vibration in the roof at the junction were upto 4.3 times the pillar vibration. It was observed that coal chips detached from roof when the peak particle velocity reached 131 mm/s or high. The vibration magnitude recorded was higher in upper seams openings than in below seam openings. Rapid attenuation of vibration was recorded in below-seam openings at similar locations. Appropriate particle-charge weight-distance equations were established to calculate the safe explosive weight per delay to be detonated in open-pit mine for safety of multi-seams workings of underground mine. The support for the galleries and junctions were further modified for the working seams to ensure greater safety.erground Coal Mine

Jan 1, 2012

By D. Fry, S. Hunsaker

Ammonium nitrate in explosives and sulfides in reactive ground have the potential to react at ambient and elevated temperatures resulting in premature detonations. The Australasian Explosives Industry Safety Group (AEISG) published, in 2006, a Code of Practice1 for elevated temperature and reactive ground. This paper reviews the chemistry, general reactivity of various ground types, elevated temperature hazards, and testing protocols contained in the code, that are industry best practices for managing ammonium nitrate-based explosives in elevated temperature and reactive ground conditions. In addition to reviewing the 5th edition AEISG Code of Practice, data is presented validating the recommended sampling guidelines within the code. Dyno Nobel has been screening reactive ground samples and performing sleep time testing since the code of practice was first released. Test results demonstrate the effects of samples that are allowed to oxidize before testing and are shown to be subsequently less reactive and not representative of the actual hazards facing mining blasting operations. Results also show that for a given reactive ground sample, reaction times decrease with increasing temperature. Data also quantify the delay in reaction time given by inhibited products. These results emphasize the importance of proper sampling and preparation of samples to accurately characterize elevated temperature and reactive ground hazards. They also demonstrate the efficacy of inhibited products in managing these hazards

Jan 1, 2024

By Ajoy K. Singh, B Mohanty, P K. Singh

A study was conducted to investigate the damage potential to underground multiseam openings caused due to vibration generated by open-pit coal mine blasting. The objective was to recommend optimal explosives weight per delay to be detonated in open-pit blasts to ensure the safety and stability of underground openings. Sixteen blasts with varying charge weights and initiation sequences were conducted at Samleshawari open-pit mine and eighty four blast vibration data were recorded in the Hingir Rampur underground colliery in India. Analysis of vibration data showed that roof of the underground openings vibrated with much higher amplitudes compared to those in pillars and floors. The amplifications of vibration in the roof at the junction were upto 4.3 times the pillar vibration. It was observed that coal chips detached from roof when the peak particle velocity reached 131 mm/s or higher. The vibration magnitude recorded was higher in upper-seam openings than in belowseam openings. Rapid attenuation of vibration was recorded in below-seam openings at similar locations. Appropriate particle velocity-charge weight-distance equations were established to calculate the safe explosive weight per delay to be detonated in open-pit mine for the safety of multi-seams workings of underground mine. The support for the galleries and junctions were further modified for the working seams to ensure greater safety.

Jan 1, 2011

By Joshua Hoffman, Rhys Baker, Tim O’Brien

Numerous agencies in the Executive Branch of the United States Federal Government have regulatory jurisdiction over the explosives industry. These agencies develop the rules by which the explosives industry must operate, and many have the authority to enforce those rules. Likewise, there are entities in the Legislature that have oversight of those agencies and develop the laws that agencies must operate under. These entities in the Legislative Branch are Congressional Committees. Each committee has their respective jurisdictional authority over various agencies and issues. There are several Congressional Committees with jurisdiction over the agencies that govern the explosives industry and they differ slightly between the House of Representatives and the Senate. This paper discusses this division of power as it relates to the explosives industry. Each branch is responsive to the public and the processes through which each promulgates regulation and legislation require public input in different forms. Options for civic involvement for engaging each of these bodies of power in their respective processes are presented. The differences between legislation and regulation are highlighted along with the processes by which each are promulgated. A proper understanding of the governmental mechanics that affect the explosives industry are critical for the industry to be able to be proactive in playing a role in these processes in a democratic way.