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By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan, Umit Ozer, Kagan Ozdemir

In the condition that drilling and blasting technique is inevitable depending on the rock mass and material characteristics on mining activities, the fragmentation rate and particle size distribution of the muckpile after blasting has important influences on the performance of subsequent mining activities such as loading, hauling, crushing, grinding etc. and the total costs of that mine. Drilling and blasting is an important step in this process chain and it's results such as fragmentation, muckpile shape and looseness, dilution, damage and rock softening effect the efficiency of downstream processes. There is an increasing body of blasting research indicating significant impacts in these downstream processes.

Jan 1, 2007

By Mark A. Williams, James D. Humphrey

Without question, draglines are one if not the most effective tools available to the surface mining industry for overburden handling. With few moving parts and a two- or threeman crew, this machine silently sits and chews into millions of yards of overburden annually. A 100 cubic yard machine operating for 30 years will excavate three-quarters of a billion yards of material during that time. That is 750,000,OOO yards of material!

Jan 1, 1990

By Roberto Folcht

The obligations of the European Directive 96/82/EC on the control of major accident hazards, the so-called Seveso II Directive, became mandatory within the E u ropean Member States February 3, 1999. Explosive products have been included within the Seveso II Directive, in the categories of substances capable of generating a major accident. In addition to taking “all measures necessary to prevent major accidents,” explosive manufacturers are also obliged “to limit their consequences for man and the environment.” However, for explosives in particular, no pro c e d u res, nor specific re f e rence values for damage calculation, are given either in the Directive or in the corresponding Italian Legislation, “Ministry of the Environment decree of 20 Oct. 1998.” This article presents a simplified but scientifically rigorous approach for the first approximation calculation of the effects on the surrounding area following an accidental explosion. As an example of the method of calculation, the damage areas in a hypothetical explosives manufacturing facility, as shown in F i g u re 1, will be anal y z e d . The method proposed in this article can also be used for the analysis of explosions of gas in tanks or pipelines,

Jan 1, 2004

By Gunnar Persson

The borehole pressure/time history of blasting practice is simulated in a twin pendulum apparatus, where the expanding shotfiring gases force two steel slab swingers apart. A pilot installation built at SveDeFo is described. The relevant factors, that govern the use of this test method as a means of classifying explosives with respect to their toxic fume potential, are described.

Jan 1, 1996

By Jean-Guy Levaque, Robert Ethier, Ron J. Elliot

This paper presents data gathered during a comprehensive study on the impact of improvements to fragmentation in a major Limestone quarrying operation. The full impacts of gains in fragmentation are tracked through the mucking, crushing, and grinding phases of the operation.

Jan 1, 1999

By Scott Orenstein

Construction blasting has allegedly been the cause of property damage in the following situations: (1) When the detonation of the shot hurls rock and debris into the air that causes property damage upon impact; and (2) When property owners notice cracks in their walls and foundations after they experience the momentary vibrations that coincide with the detonation of the shot. The current state of the law for both these situations is firmly established. Blasting is classified as an abnormally dangerous activity, for which the blaster is held strictly liable, whether the damage is the result of flying debris or vibrations and concussions generated by the blast. It is when the alleged blasting damage is supposedly from concussions and vibrations, however, that the courts usually reach the wrong result. The typical scenario involves property owners that thoroughly investigate their property after feeling blast generated vibrations, and find cracks that they believe did not exist beforehand. Most often the truth is that the property owners have never noticed these cracks before because they have never looked that closely before. Any structure has a certain number of cracks due to a variety of causes, such as settlement overtime and temperature and humidity changes.

Jan 1, 2004

By E. Contestabile, R. von Rosen, R. Guilbeault, R. Fouchard, P. Lightfoot

In August 1998, a truck loaded with 18 tons of blasting explosives, including over 13 tons of ANFO, left the road near Walden, Ontario. The crash caused a fire; approximately 30 minutes later a large detonation occurred, causing substantial damage to the roadway and local property. Although nobody was injured in the explosion, the consequences of a similar incident in a heavily populated area could have been catastrophic. Following the Walden incident, Transport Canada and Natural Resources Canada embarked on an extensive experimental program to determine the cause of the detonation. This paper describes part of that experimental program, designed to understand better the thermal decomposition of ANFO.

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 Thomas M. Keevin, Gregory L. Hempen

"Natural resource agencies, under various regulatory authorities, are challenged with permitting underwater explosive use while at the same time protecting aquatic resources. Deciding on whether or not to allow use of explosives requires striking a balance between development and aquatic resource protection. A company’s goal in underwater explosive use is to select methods that are both expedient and cost effective. The use of explosives is often the best alternative for engineering reasons or economic considerations. Over and above legal requirements, indiscriminate destructionof fish and other aquatic resources is not in a company’s best interests because of concerns relatingto public image, as well as the need to secure future contracts."

Jan 1, 1995

By Dale S. Preece

"The computer program DMC (Distinct Motion Code) [Taylor and Preece, 1989a] was developed in 1988 and 1989 to predict the motion of rock following a conventional blast. DMC executes very efficiently on a CRAY type computer due to the high degree of vectorization and also due to the use of spherical elements [TayIor and Preece, 1989b]. Bulking mechanisms developed specifically for use with spherical elements include rotation-induced dilatation and aspect ratio > 1.0 [Preece and Taylor, 19901. Rotation-induced dilatation allows the radius of the sphere to expand as a function ofsphere rotation to simulate the interaction of corners and sides of blocky rocks. An aspect ratio > 1.0 is achieved by kinematically tieing spheres together."

Jan 1, 1991

By G K. Jorkenson

Blast designs to cast a percentage of overlying waste rock off coal seams differ greatly from conventional blast designs for surface coal mines. Today, blasting engineers can benefit from computer simulations to test various blast designs and reduce cost and time spent on the old trial-and-error method.

Jan 1, 1989

By Stephen Chung, Graham Mustoe, Joe Haid

In an open cast coal mining operation, a 305 m (1000 ft) long by 49 m (160 ft) thick overburden cast blast can produce more than a million cubic yards of broken muck that needs to be removed before the coal recovery process can start. In the Powder River Basin of Wyoming, it is common to see 30 to 40 percent of the overburden cast to a spoil that does not require rehandling with heavy equipment. Therefore, the higher the percent cast, the better the cast blast is rated. However, depending on the shape of the muck profile, there is often 20 to 30 percent of the muck standing in front of the high-wall. This portion of muck would require a number of dozers to push down to the dragline pad level. From the mine operator point of view, it is believed that for a given muck profile, there should be an efficient dozer pushing method such that a dragline pad can be developed in the shortest time. As a tool for analyzing this dynamic problem, a 2-D discrete element model, i-PushTM, has been developed to simulate a dozer pushing operation. This mechanistic model takes into account the dozer blade geometry, the dozer operating procedure (e.g. cut-depth, blade fill distance, forward and reverse speeds at specific slope angles), material density and cohesion. To demonstrate how i-PushTM can be used to help determine the most productive push routine, this paper presents three dozer push methods to compare the effectiveness of pushing at 3:1, 4:1 and 5:1 push angles.

Jan 1, 2006

By Donald F. Rapp, Thomas E. Brown

The application of commercial explosives in an underwater environment, sometimes referred to as submarine blasting, presents the blaster with a unique set of demanding conditions which require exacting detail in design and application. There are two basic methods for removing rock under water: 1) "the drill and blast method"; and 2) "the dobying method." Because it is a far less effective method of blasting, dobying will not be addressed in this 'paper but suggested criteria can be found in the 16th Edition of the **DuPont Blasters' Handbook" page 371. Some examples of submarine blasting utilizing the drill and blast method include channel expansions, harbor construction, bridge pier footer excavations, utility excavation and demolition work.

Jan 1, 1994

By C. Anderson, Mike Michaelis

Ammonium Nitrate (AN) - based commercial explosives are non-ideal explosives. This is because the chemical and physical structure is heterogeneous on a distance scale comparable to, and in many cases larger than, the reaction zone in the detonating explosive. Such systems consist of inter-molecular fuel-oxidizer systems. Attempts have been made to minimize the heterogeneous nature (inter-molecular distances) of these explosives; emulsion systems are the latest examples of these commercialized AN-based explosives which balance cost, utility and performance. This latter factor (increased performance) is a direct result of increasing the contact between oxidizer and fuel.

Jan 1, 2003

By N. Jayaraman, V. Srikant, A. Radhakrishna

Addition of a 500 MW unit to the existing units at Ramagundum Thermal Power Station requires blasting of large volumes of rock very close to sensitive installations like Turbo generator, Generator transformer and Power cycle equipments. Levelling of the areas and excavations for footings are, therefore, to be carried out cautiously. The existing sensitive installations should be protected against ground vibrations and flyrock. The paper describes the details of a few of the many blasts carried out successfully wherein the ground vibrations were restricted and flyrock was avoided.

Jan 1, 2003

By William Hustrulid

Pre-split blasting is a primary technique for creating slopes with a minimum amount of unwanted damage to the remaining rock mass. Rock slopes created in such a way have both safety-related and economic advantages. The applications extend from road cuts to rock quarries to large open pit mines. For example, as deep open pit mines approach the end of their operating lives, slope steepening is one option to be considered. To be able to safely achieve and maintain steepened final slopes, good blast design techniques must be available and applied together with close operational control. Pre-split blasting is an important element in this slope creation process.

Jan 1, 2007

By James H. Owen

Because of price structure, ANFO is normally considered to be the most cost effective explosive used in quarry blasting. Results indicate that bulk smulsion can be more cost effective in applications where hole sizes range up to 6.5 inches in diameter while providing the simplicity of single product loading and storage. This can be accomplished without any fragmentation and/or movement loss usually in patterns which are about twice the size of ANFO patterns, allowing the combined drilling and blasting cost to be less when using bulk emulsions. Examples are presented supporting this concept using actual field results along with some simple calculations which take into account differences in the products such as density, matrix and detonation velocity.

Jan 1, 1998

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 Paul Worsey, Seokbin Lim

There are two major types of shaped charges, conical and linear (Ref 1, 2). Conical shaped charges are used to perforate targets and are mainly used by the military as anti armor weapons and by the oil industry for oil well perforation. In contrast, linear shaped charges are primarily used to cut metal in the demolition industry with other uses including separating devices in the space industry. There is a large amount of material published on conical shaped charges because of the high level of defense industry research and funding, however in stark contrast there is very little published on linear shaped charges.

Jan 1, 2003

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