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By Syed M. Tariq, Paul N. Worsey

Presplitting is a now a universally accepted perimeter control technique in rock excavation. The success of presplitting and the smoothness and integrity of the resulting perimeter is largely dependent on the nature of joints in any given formation. Many facets of jointing have been previously investigated. The results of the effects of joints frequency and spatial positioning were presented by the authors at the ISEE annual meeting last year. This paper includes the results of further research into the mechanism of presplit blasting being carried out at the Rock Mechanics and Explosives Research Center of the University of Missouri- Rolla.

Jan 1, 1996

By Robert B. Hopler

First, a definition: “an explosive is called a permissible explosive when it is similar in all respects to the sample that passed certain tests by the national Bureau of Mines, and when it is used in accordance with the conditions prescribed by that bureau. * This was the definition as stated in Miners’ Circular No. 2,” published by the United States Bureau of Mines in 1911, and it is still applicable today. Of course there have been changes over the years, with the name “MSHA Permitted Explosive” now the legal terminology since January 1989, but the old 1911 circular still tells us what the material is. Note that the definition doesn’t even specifically state “coal mining.” A permissible can be required in guy underground operation that is deemed to have a gas or dust hazard, although in 1911 it was certainly meant to refer only to coal.

Jan 1, 1995

By Steve Dillingham

There are some blasters and blasting companies that just seem to have better safety reputations than others. This is in spite of the fact that they are essentially doing the same type of work under similar conditions. To achieve that enviable safety reputation, it simply comes down to a strong safety culture prompted by a responsibility for others, as well as yourself and your company.

Jan 1, 2003

By Rachel Bernau

Water wells, aquifers, and pipelines rarely incur damage from nearby blast vibrations. Extensive ground vibrations may cause a drop in the water table thereby changing an aquifer’s structure or drying up a well. Studies on the reactions of aquifers and water wells have been performed in Montana, North Dakota, and the Appalachia Coal Region. All of these studies reported that vibrations did not change the properties of the monitored aquifers and water wells. Rather, evidence suggests that any incurred damage was caused by block motion and downsloping.

Jan 1, 2001

By Gordon M. Matheson, David K. Miller

Possible impacts to the water quality and production capacity of ground water supply wells by blasting is a common cause of complaints for blasting contractors, mining companies, and local regulatory authorities. The major complaints of changes in well water quality include; turbidity, discolored water (red, brown, black, yellow and milky water), and nitrate and/or coliform contamination. The major complaints for changes in well water production capacity include: loss of quantity production, air in water and/or water lines, damage to pump, and damage to well screen or borehole.

Jan 1, 1997

By J E. (Boet) Coetzee

SAFEX International, as the name suggests, is a global organisation, which has the fundamental objective of improving the safety of operations concerned with the manufacture, storage, transport, and use of commercial and military explosives and pyrotechnic products throughout the world. It is a nonprofit making organisation of manufacturers of explosives from all parts of the world, founded in 1954 with the aim of exchanging experiences within the explosives industry. Every third year SAFEX organises a Congress during which members present papers on selected themes and discuss reports of significant incidents that occurred since the previous Congress. Admission is for SAFEX members only, thereby creating a safe environment for discussing problems “within the family”. The XV Congress will celebrate the Association’s 50th anniversary in Geneva where it was founded. An overview of the Congress indicates its structure and covers aspects such as the training event, technical seminars and the themes for the plenary sessions and associated workshops. The paper also highlights the special event for the chief executives of member companies and the review of incidents that occurred in the industry since the last Congress. The Congress concludes with a social programme for delegates and their partners on the last day.

Jan 1, 2005

By A Brodbeck, AT Spathis

Australian regulatory control of ground vibration and airblast arising from mining, quarrying and civil construction operations is spread across a number of federal, state and local authorities and across a number of departments with various jurisdictions. The Australian Standard AS 2187.2 contains an informative appendix on damage-related criteria and it is the primary reference for the regulators. The complete standard and the informative appendix is currently undergoing major revision with a focus for the latter on implementing frequency-dependent criteria for ground vibration. Certain directions for change have been raised for consideration by the standing committee, ranging from fundamental issues of measurement and interpretation and others that overlap human comfort criteria. It is anticipated that some of the suggestions will eventually make their way into future standards after an adequate period of consultation and consideration by both the Australian public and others involved in the associated industries.

Jan 1, 2005

By R. K. Wharton

The paper reviews the development of European harmonised standards for fireworks, recent major incidents involving the bulk storage of fireworks which led to research funded by the European Commission, progress with the forthcoming European Regulation on pyrotechnics and potential issues relating to the certification of products within the scope of the new Regulation.

Jan 1, 2005

By David R. Ziegler

The concept and facts concerning "threshold blast damage" are not considered "general knowledge". Perhaps because of a lack of knowledge, understanding, and experience of blasting effects, property owners and lay-persons may attribute a wide range of common cosmetic conditions to "blasting damage".

Jan 1, 1997

By Fumihiko Sumiya, Kunihisa Katsuyama, Yuji Ogata, Yuji Wada, Yukio Katoh, Yoshikazu Hirosaki

In our previous work, the results of photographic observation using a high speed framing camera showed that the difference between precursor air shock wave velocity and detonation velocity was primary factor for the channel effect. It is assumed that the decreasing precursor air shock wave velocity can prevent the channel effect in charge hole.

Jan 1, 1996

By Douglas A. Bartley, Davey Bickford, Raphael Trousselle

The long awaited arrival of a high accuracy detonator to reach the explosives end user will provide new opportunities the blasting community to become better equipped and able to improve upon the current approaches and methodologies used in blast design as they apply to the mitigation of adverse effects from blasting. This paper will detail the approach and findings throughout a several month research project to quantify the high accuracy detonator benefits and to mitigate a long standing vibration problem at a hard rock stone quarry in the state of New York. The tests conducted in this study were designed to provide important information as to the relationship between the use of high accuracy detonators and overall blast performance in terms of ground vibration prediction, control and improved rock fragmentation.

Jan 1, 1998

By Greg Parker

"As the Explosives Industry continues to evolve and condense, those involved, such as Blasters,Contractors, Distributors and Consultants, continue to be challenged by both internal and externalforces. Increased pressure by government agencies, higher safety standards, new levels of technology and mandatory certification programs, are forcing us to expand our awareness and increase our levels of efficiency. These higher standards require increased awareness. Increased awareness requires better training programs and better supervision with emphasis on production and the employee. This means the desire to improve must be instilled from the top down. this paper will explore the current impediments to this goal and discuss the possible solutions for achieving greater safety awareness, increased production and higher levels of personal achievement. Through the use of audio/visual aids, I will attempt to show the discrepancies as well as the solutions."

Jan 1, 1999

By Douglas A. Anderson

It is quite common for people exposed to blast vibrations to ask questions such as "How big was that blast on the Richter Scale?" Although it is tempting to dismiss such questions out of hand, for the lay person it is understandable that something which shakes their house should have some sort of measure attached to it. Since a layman doesn't usually know about particle velocity, frequency or the other terms used in describing and regulating blast vibration, the Richter Scale is usually the only measure they can relate to.

Jan 1, 1994

By Lyall Workman

"Many new technologies, useful to the mining and quarrying have recently come to market. Some are applicable to drilling and blasting operations. Others apply to subsequent mining unit operations and can generate data for objective assessment of blasting results. These new technologies can accurately capture the information component of blasthole drilling, andindeed of each unit operation. Knowledge can be extracted from this information and passed forward and back through the mining system to improve operations and factually assess results. This leads to an evolving and improving system."

Jan 1, 2001

By Steve Dillingham

Change occurs all of the time. In fact, it’s fair to say that change is a constant. Sometimes the change is inconsequential, but sometimes the change impacts us d i rectly and severely. Take regulations, for instance. Complying with regulatory requirements is just part of the job for those involved with explosives. But in recent years, it seems as if new or revised regulations in areas such as hazardous materials training, drug and alcohol testing, security issues, or local licensing/permitting standards are changing the way we operate on a recurring basis. Simply keeping track of all of these regulations has become a full-time job.

Jan 1, 2003

By James Rowland, Isaac Zlochower, Richard Mainiero, Michael Sapko

The National Institute for Occupational Safety and Health (NIOSH) carried out exploratory laboratoryscale studies to identify factors that may contribute to nitrogen oxides (NOx) production associated with non-ideal detonation of blasting agents. Explosive admixture with drill cuttings, loss of fuel oil in ammonium nitrate and fuel oil (ANFO) from wicking, ammonium nitrate dissolution with water, degree of explosive confinement, ANFO density, and critical diameter were identified as contributing factors to increased NOx production under the laboratory test conditions. Experiments were also conducted to examine the effectiveness of various additives in reducing the NOx production from ANFO, emulsion, and ANFO/emulsion blends. Aluminum powder, coal dust, urea, and excess fuel oil in ANFO formulations were tested and were found to reduce both the nitric oxide (NO) and nitrogen dioxide (NO2) production. Fumes measurements were obtained in the NIOSH underground closed chamber from the detonation of 4.5-kg (10 lbs) charges in schedule 80 seamless steel pipe and from detonations in light weight galvanized steel stove pipe. Some exploratory tests were also conducted with 0.8-kg (1.8 lbs) charges of pulverized ANFO initiated with 0.08-kg (0.18 lbs), 50/50 (Pentolite) boosters (in the NIOSH 12-ft (3.7-m) diameter steel sphere) to measure the degree of fumes production associated with post-detonation oxidation. Ammonium nitrate, emulsion and Pentolite boosters were also detonated in an oxygen-poor environment.

Jan 1, 2002

With the ever increasing problems of narrowing profit margins, and increased liability, a solution/option to SEE members is needed. It is essential that all members understand the benefits of utilizing explosives in combination with other methods of achieving the required result on difficult rock or concrete removal projects.

Jan 1, 1995

By Norm Tienkamp, Normand Martineau

Through the normal course of operation, mine operators are living situations where blast results need to be measured. It becomes the supervisory group responsibility to select evaluation parameters with appropriated and available technics. In Mine Selbaie's case, we have retain the following parameters: rock fragmentation, oversize fragments, rock pile movement, grade rupture.

Jan 1, 1996

By Lyall Workman, Jack Eloranta

Blasting has an important impact on mining and milling well beyond the necessary ability to dig and load the ore efficiently. There is an increasing body of blasting research indicating significant impacts in crushing and grinding. These include increased production through higher output and fewer delays for bridging and jamming by oversize. In addition, fragmentation better suited to the crushing and grinding system is indicated to lead to reduce energy consumption by these activities, an important result in today’s environment. An important component of optimum fragmentation for this purpose appears to be micro-fracturing within individual fragments. This differs from fragmentation criteria for loading which focus mostly on fragment size. Therefore, one must analyze blasting broadly to obtain satisfactory results throughout the operation.

Jan 1, 2003

By Jeff Peterson, Alastair Grogan

During the winter of 2001/2002, a number of seismic exploration projects were carried out in the Mackenzie River Delta area of the Northwest Territories, in Canada. The purpose of the seismic projects was to identify potential drilling targets for subsequent drilling programs, using explosives as a seismic source. Recent changes to fisheries regulations meant that blasting under lakes, the Mackenzie River and offshore from the delta, was not allowed to induce water overpressures in excess of 100 kPa in these water bodies, and that a water overpressure monitoring program had to be conducted to confirm that this requirement was being met. This paper describes the water overpressure monitoring program on one of the exploration projects, presents the results of the monitoring, and discusses the challenges of carrying out this work in the middle of an arctic winter.

Jan 1, 2003