Search Documents

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By Steve Dillingham

Whenever misfired holes or portions of misfired holes remain after a blast is fired, a hazardous situation exists until the unfired explosive materials have been disposed of properly. Yet, there are so many factors that can contribute to misfires that it is impossible to give blanket instructions on how to handle them. To complicate matters, misfires today are rare due to reliable blasting products. As such, it isn’t very surprising that many blasters have never had to deal with a misf i re condition. While the likelihood of a misfire occurrence is minimal, you should always be pre p a red to handle a misfire should you be involved in such an event. To begin, every blaster and blasting org a n i z a t i o n should develop a misfire policy which contains the company’s safe operating pro c e d u res, emergency contact list, as well as any regulatory compliance re q u i re m e n t s . Tailgate and/or company-wide safety meetings should communicate the company’s contingent misfire pro c ed u res and any special site-specific precautions BEFORE the start of any project.

Jan 1, 2004

By Victor C. Bryan

One of the most sought after answers in any consideration of blasting activities relative to mines and quarries is how to safely and efficiently use explosives. While that discussion might be relatively straightfonvard in a “site specific” situation. it becomes more complex when viewed from a broad geographic perspective. Such is the case in considering the operations of one United States producer of crushed stone with surface and underground mines spread over a thirteen state area. Differing geologic environments set conditions that dictate to the blaster as now specifically to get optimum results from the blast hole. This treatise is a discussion of the various methods, materials, and principles used in conducting such blasting operations.

Jan 1, 1991

By Douglas A. Anderson

The simplest method used to predict ground vibration from blasting is scaled distance -the distance from a blast divided by the square root of the Pounds per delay. Pounds per delay is defined as the number of pounds of explosive detonated within an 8 millisecond (ms) interval. Based upon this definition, regression plots of peak particle velocity vs. scaled distance have been used to determine likely values of peak particle velocity.

Jan 1, 1989

By Bruce Vandenberg, R F. Chiappetta

"The High Speed 2D Analysis program allows the user to bring in data from several different sources. Of course, keyboard entry is included as a source. Other data is inputted through the serial port (X-2321 of the PC. Two types of data are transferred via the serial port. The first is the tablet digitizer data. The three types supported presently are the GTCO, tablet digitizers. and the Calcomp 2500 and 9100 series To transfer digitized data turn on the selected digitizer and place the cursor on the tablet. Enter the High Speed pmg.ram and select from the Input Program menu the Digitize Inputs(20) option and follow the instructions. TO exit the session, either a keyboard entry or a cursor button is pressed. The second type of serial port input Is from the collectors of the listed survey systems. Typically a file transfer program will be used to send the data from the collector to the PC. This topic will not be addressed at this time."

Jan 1, 1989

By Mark Svinkin

The purpose of this paper is to present an overview of recommended existing criteria of ground vibrations generated by blasting. It is shown that these criteria have limited liability because they were found for specific categories of structures. A new approach based on measurement of structure vibrations is suggested for assessment of damage in structures subjected to blasting vibrations. This approach provides the flexibility of implicitly considering a variety of soil-structure interaction and structure conditions. It is explained a new frequency-independent safe-level criterion of 51 mm/s (2 in/s) for the PPV of structural vibrations. Attention is brought to use seismographs properly calibrated for the required frequency range. Positive flexibility is demonstrated in assessment of structure and component of concern vibrations from blasting.

Jan 1, 2003

By Richard Hosley, James Daley

Every grey haired member of the explosive’s industry has said at least once, “We have to get some younger blood into our industry, I might want to retire someday.” And many a youngster who loves to see explosions has wondered how to get involved in such an exciting, yet intimidating, industry. While there are many answers to these questions, an internship program is a great answer to both

Jan 1, 2014

By Mats Keisu, Bengt Niklasson

The Sofia project has increased the level of knowledge and technique within tunnelling, drifting and contour blasting.

Jan 1, 1992

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 Larry Schneider

"0 ne of the incentives that led to the development of non-electric shock tube initiation systems was the desire within the industry to improve detonator safety. And to the extent that nonelectric initiators are immune to the hazards of stray current and radio frequency energy found on normal blast sites, an advancement in safety has been accomplished. However, as a cautionary note, it is important to realize that there are still many hazards associated with any initiation system. While some of these hazards may differ from those associated with electric detonators, others are identical to those associated with any type of initiation system. For instance, contrary to what some uninformedblasters may believe, lightning remains a hazard when using nonelectric initiation as well as electric initiation."

Jan 1, 1995

By Kai Nielsen

The paper presents the results of several industrial and laboratory blasting, crushing and grinding tests and experiments investigating how blasting can influence the subsequent crushing and grinding operations. The paper also describes how these results can be used in order to optimize the entire comminution process from solid ore to a semifinished or marketable product. Two cases are presented, one looking at the processing of fine grained taconite ore, and the other discussing the processing of raw milling product for cement burning.

Jan 1, 1998

By Bill Williamson, Doug Richmond, Kerri Kuntz, Gus Gilman, Larry Heywood

This was a description by the poet of what occurred over two centuries earlier to Hannibal’s troops as he passed through the Alps. Interestingly, the pass that many feel is the route that Hannibal chose, Col de la Traversette, is the sight of possibly the earliest avalanche mitigation known. Monastery records describe a tunnel built in 1470, near the top of the pass designed to protect pilgrims from the upper slopes. For the next several centuries, avoidance and reinforced structures were the primary tactics to defend from avalanches

Jan 1, 2009

By Dale S. Preece

The blast-induced movement and final location of geologic layers that may cause environmental problems can be predicted using discrete element methods. This prediction capability can be used by mine operators to locate the material in the muck pile during excavation which would allow encapsulation to prevent groundwater infiltration.

Jan 1, 1994

By Norman Disley, David B. Counter, Lionel Hebert

Misfires in underground and surface production blasts can be costly. Costs can arise from loss of resource, production interruptions, having to redrill or otherwise refire the blast (a hazardous process at best), due to added secondary blasting or breakage, and/or from increased LHD maintenance costs attributable to poor fragmentation.

Jan 1, 1996

By Kwang-Tae Kim, Yong-Kun Choi, Jeong-Soo Chong, Yun-Jae Lee

An annex building at the former Agency for National Security Planning(NSP) complex located in downtown Seoul was demolished by progressive collapse method. This work was done as a part of efforts to restore the landscape of Namsan Mountain which lies in the Center of Seoul. The five-story reinforced concrete structure was razed in 5.5 seconds by the 29kg of high powered explosives which were placed in some 320 holes in the building with floor area of 2,577 m². The asbetos and all the other finishing materials in the building were removed before the demolition and the specially coated wrap minimized the spread of blasting dust. Seismic and air overpressure waves were monitored at 8 points, which were below safety limits and the continuous communication with neighborhood prevented any complaint.

Jan 1, 1998

By Roger "Dean" Skaggs

Mechanical rock drilling is about 150 years old, and the fundamental principles of augering, penetration and dragging, pressure and rotation, and percussion have not appreciably changed. Surface mining blasthole drilling employs relatively shallow blastholes (to about 100 to 130 feet or 30 to 40 meters) with respect to the blasthole diameter and hole alignment while problematical is not a major universal problem. Modem underground mining methods are spacing development levels up to 400 feet (130 meters) apart, to take advantage of high powered mechanical drilling methods, requiring very long blastholes compared with surface mining. Blasthole alignment is a major problem in underground mining and this paper will address the aspects of percussion bit design which impact on hole alignment and drilling and blasting costs, i.e. bit geometry, cuttings removal, penetration-retraction.

Jan 1, 1997

By R J. Johnson

The development of "SANFO" has provided the Mining Industry with a LOW COST HIGH GAS VOLUME, VARIABLE DENSITY, Blasting Agent which can be blended "On Site" in a simple Agitator mixing and charging system by mine site employees.

Jan 1, 1996

By Roberto Folchi

"This article deals with the excavation of a tunnel below the town of Isola LIRI, nearFrosinone, in central Italy. The tunnel was driven into a conglomerate formation, of lacustrine_fluvial origins, consisting in carbonate clasts with a sandy_silty matrix and calcitic cement. ""Drilling andblasting"" had to be adopted in place of a tunnel boring machine which had showeduneconomical performances. Good advance speed rates were achieved notwithstanding thepresence of some above structures to safeguard. The nearest structure (an old votivechapel) was less than 10 meters (33 ft.) far from the tunnel crown; the nearest residentialstructure was at about 15 m (49 ft.)."

Jan 1, 1993

By R F. Hoeberling

"The use of ground penetrating radar (GPR) for geological purposes has been underway for almost two decades. The commercial need for a versatile GPR that can rapidly identify buried objects andunderground voids has been recognized and is an area of research that has already proved useful for several geological activities. Several types of GPR endeavors have been reported in the literature, including exploration of placer deposits (Davis, et al. 1985) and heavy metals (Hammond and Sprenke, 1991), improving oil recovery (Witterholt and Kretzschmar, 1984), investigating coal seams (Coon, et al., 1981), stratigraphic survey (Fisher, et al. 1992), Lunar soils characterization (Olhoeft, et al. 1975 and Strangway, et al. 1977), characterization of rock around mine tunnels (Cook, 1985), location of old mine workings (Scaife, et al., 1992), location of abandoned gas wells in coal seams (Kemerait, 1992) and survey of hazardous waste burial areas (Horton, et al., 1981). Coal seammapping has been developed using a related continuous wave, phase discrimination technique (Stolarczyk, 1990). As the technology for the radar equipment and the onsite computational power has increased, many new applications have become feasible. This article will describe the present status of the GPR technology and indicate some of the exciting possibilities for nearterm prototypes now being constructed."

Jan 1, 1994

This paper is concerned with the blasting of rock in mining. The most common purpose of blasting rock is to cast it or to disrupt its structure sufficiently for effective digging and subsequent removal.

Jan 1, 1991