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By Geoff Baldwin, Alastair C. Torrance

The use of monitors to assess equipment performance is carried out on a routine basis in many industries. The benefits gained through process control in knowing exactly how the equipment is working far outweigh the initial capital costs of the monitor. In the mining industry several dragline monitors have been developed and installed on equipment through out the world, but to date none has been fully accepted by the industry. This paper describes the use of a sophisticated monitoring system which incorporates an onboard processor to assess both dragline and blast performance. The use of a radio telemetry link for data transfer has removed the need for manual data collection and transfer, leading to a more efficient and powerful system. Significant effort has been put into the development and verification of a dig index to allow blast performance to be objectively assessed.

Jan 1, 1990

By Harry Verakis, Thomas Lobb

This paper is a summary and an update of the underground mine blasting accident investigations and studies previously conducted by the Mine Safety and Health Administration (MSHA) and the former US. Bureau of Mines. Blasting accidents are usually a small percentage of the total number of mining accidents. However, blasting accidents continue to occur and the severity of these accidents is disproportionately high with respect to other types of mining accidents. In 2000, about 5.7 billion pounds of explosives were produced in the USA. The mining industry consumed the greatest portion of explosives manufactured for blasting with about 67 percent used for coal mining. Metal and nonmetal mining operations account for about 23 percent of the use of explosives. The use of permissible explosives in underground coal mines continues to decline (3,373,069 pounds for 2000).

Jan 1, 2002

By Manuel Gutkrrez, Nasslo Gallardo, Arturo Cancec

The study done in Dofia In&s de Collahuasi aims to improve the fragmentation in one of the most difficult rocks to deal with in an operation, It is the Ignimbrita. In order to avoid ejections and to increase the efficiency of the explosive it has been obtained an improvement in the stemming quality by using the Blasting Optimisation Program in Ignimbrita. Different materials were used in the stemming. In 1997 it was used soil material (Paleorrelleno), then in 1999 started the use of crushed gravel and during this year it is being implemented the utilisation of Stemtite only loaded with drill cutting. The first improvement was obtained with the utilisation of gravel, yielding good fragmentation results in comparison with the stemming with detritus material. The stemtite has made easier the blasting operation and it has signiticantly improved the fragmentation.

Jan 1, 2001

By BernardThierry

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts. This new type of model enables us to concurrently simulate the fragmentation of the rock, its movement and the associated seismic levels, all within a few minutes, which is a time compatible with a production cycle. Due to the complexity of the model, this article reveals the main principles and compares the results of simulations with on-site measurements in various sectors, i.e. quarries, mines and tunnels.

By Damien Bretall, William Fourney

Due to the changing face of warfare there is an ever growing need to protect the underside of combat vehicles from mine blasts. This paper presents a new method to better characterize the pressure profiles experienced by a plate as the blast develops. The explosive deformation of a small-scale plate was recorded using synchronized high-speed digital cameras, and then analyzed using 3D Digital Image Correlation software. Time-varying pressure profiles were input into an axisymmetric FEM simulation by fitting curves to data obtained from tests using Kolsky bars to measure pressures. These were then modified to find possible profiles that produce the measured deformations. It was discovered that the final deformation cannot be determined from only total impulse or peak pressures, and that it is very sensitive to the time and spatial decay of the pressures.

Jan 1, 2009

By Sehoon Lee, Duhwoe Jung, Eunsu Cha, Kyeonghwan Jeong

This case study presents the effectiveness of underground rock blasting to facilitate the trench cut in the hard rock layer using a conventional trench cutter for the construction of a diaphragm wall. Rock blastings are pre-performed up to the scheduled depth and then the fragmented rocks can be easily cut using a conventional trench cutter. Two trial underground rock blastings have been performed and the effectiveness of pre-blasting is presented in terms of a cutting rate, a loss of cutter heads and an amount of overbreak. Based on the results obtained from the trial underground rock blastings, the following conclusions can be appropriate: 1) A pre-blasting of hard rock layer located in depth can help to overcome the limitation of the trench cut using a conventional trench cutter. If the hard rock layer is fragmented after blasting, the fragmented rocks can be easily cut using a conventional trench cutter, 2) The speed of cutting works was accelerated and the loss of cutter heads was significantly reduced in the sections where the blastings were applied prior to cutting. 3) The amount of overbreak, expressed in terms of the amount of poured concrete, can be reduced to some extent. However, the location of blast holes in the trench can also contribute to the amount of overbreak. The closer the location of blast holes to the edge of the trench, the more extensive fractured and cracked zone can be formed on the face of the trench. This can increase the amount of overbreak if the trench is left empty for a while.

Jan 1, 2000

By Yeon-Ho Jin, Eui-Haeng Heo, Yun-Seok Park, Sung-Oong Choi, Hyung-Dong Min, Min-Su Jeong, Seung-Joong Lee

As rock fragmentation in bench blasting can affect the following process such as loading, hauling and crushing, its good control is essential for assessment of blasting efficiency and production cost.

Jan 1, 2015

By C Yeung, G Fitz, R Heater, P D. Katsabanis

Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction can range from sympathetic detonation to desensitization and modification of firing times of conventional pyrotechnic detonators.

Jan 1, 1994

By Peter P. Harvey

The Nonel Primadet is a non-electric delay blasting cap initiation system. The most recent field application of the system in the Southwest has been at the Magma Superior Mine, Superior, Arizona.

Jan 1, 1978

By Stuart Brashear, Lee Schettler

"The effect of water on several ANFO/emulsion blend ratios is documented by both physicalobservations and analytical testing to demonstrate the effect even small quantities of water canhave on water resistant blends."

Jan 1, 1996

By Rick W. Bellenie, Ronald L. Woolf

The Gregg River mine is located 40 kilometres (25 miles) south of Hinton, Alberta, approximately 330 kilometres (205 miles) west of Edmonton and lies against the Front Range of the Rocky Mountains.

Jan 1, 1994

By Peter Reinders, Dirk Hummel

This paper describes a newly developed Surface Remote Blasting System (SURBS) for electronic detonators, which is currently being introduced into surface blasting applications. The rationale for developing the SURBS was to meet key needs of mine operations, such as minimizing the shutdown time and the capability to conveniently initiate blasts in difficult terrain from a safe distance. Increased distance from the blast site, combined with a good overview of the site enables maximum safety during blasting. The system also removes the inconvenience of running long firing cables. The SURBS consists of the field-proven detonator and equipment technology of an existing electronic detonator system, a Surface Remote Blasting Box and a Surface Remote Blaster. The Surface Remote Blaster is the Master unit and controls the Remote Blasting Box via encrypted radio communication using a sophisticated safety technology, which guarantees that the highest safety standards are maintained.

Jan 1, 2005

By Ronald Thomas

The scope of this paper is to examine the growth of safety in an individual and offer new goals in that development. The paper will examine the individual's natural growth and show how it parallels the individual in a safety environment. An individual's new goals for safety include more than the standard accident-free conditions. The new goal strives for a safer working environment where unsafe acts are eliminated through independent knowledge and an individual's growth of interdependency in safety related areas of concern. It will explain how this goal cannot be reached unless driven from the top down in an organization but empowered from the bottom up. Various reference or support organizations will be covered. These organizations deal with safety in mining and explosive use of manufacturing. Other support organizations exist but since this paper is "Back to Basics" only a few major groups will be covered.

Jan 1, 2001

By Peter Bellairs, Anthony Bubb

The Porgera Gold Mine is located at an altitude of 3000m in the central highlands of Papua New Guinea some 600 km Northwest of Port Moresby the capital city. Access to the mine is via a five hour trip on an unsealed road from Mount Hagen the nearest regional centre or 40 minutes via air. The mine operates on a fly in - fly out basis and currently produces ore from both opencut and underground operations with the former providing the bulk of the mill feed. Opencut mining utilises conventional truck / shovel, drill and blast methods on both 10 metre and 14 metre bench heights with the larger benches being restricted to the stripping areas. This paper presents the strategy used and the results of a blast optimisation process in the opencut that was a joint effort between the mine personnel and the explosives manufacturer/supplier.

Jan 1, 1997

By Brian W. Stump

The cessation of testing of any nuclear explosive devices in all environments is the goal of the Comprehensive Test Ban Treaty. In order to assure compliance with such a treaty, an international monitoring system has been proposed. This system will include seismic, infrasound, hydroacoustic and radionucleide monitors located throughout the world. The goal of this system is the detection of any nuclear test. In preparation for this treaty, a series of monitoring system tests, focusing primarily on seismic observations, have been undertaken. The most recent of these tests, Group of Scientific Experts Technical Test Three (GSETT-3), provides valuable data for assessing future monitoring systems. During the course of this experiment, seismic events associated with earthquakes, nuclear explosions and mining explosions have been recorded. This presentation will discuss the numbers and types of mining explosions triggering the system, in a particular area. Possible implications for the mining industry will be explored.

Jan 1, 1997

By Harry Verakis, Thomas Lobb

Widespread use of ammonium nitrate compositions for mine blasting operations has led to various bulk transport vehicles designed especially for the explosives industry over the past half century or more. The advancements in explosives technology and continuing developments in bulk transportation have resulted in a variety of blasting agents and, more recently, oxidizers being transported and used from specially designed bulk transport vehicles. It is estimated that about 2000 bulk transport vehicles are used in mining operations. Many of the bulk vehicles carry about 15,000 to 33,000 pounds (6808 to 14,968 kilograms) of payload and some can carry up to 50,000 pounds (22,679 kilograms) for large open cast mines. Thus, it is imperative that detailed knowledge and safety instructions are available from the blasting personnel and mine management should an unplanned incident such as a fire occur with a bulk transport vehicle at a mine site.

Jan 1, 2008

By Dadan Munawar, Benny Gunawan

Blasting at Sebesi in Central Tutupan Pit area in South Kalimantan, Indonesia is planned to be using emulsion, where used oil makes up 50% of the total emulsion fuel. The significant amount of used oil from various mining operation units had been of deep concern since it might be reused to implement environmental programs by substituting 50% of fuel with used oil in emulsion, thus decreasing fuel consumption and increasing efficiency by reducing fuel cost. Used oil must pass laboratory test to meet the Indonesian National Standards (SNI) No. 7642:2010 of used oil specification. Other considerations include the location which is adjacent to the mine office facilities with a radius of <1,750 meters (5,741 feet). Thus, appropriate methods must be performed to meet the SNI No. 7571:2010 of vibration threshold in order to implement safe blasting technique and prevent potential damage.

Jan 1, 2015

By Kevin Phelps, Jason Baird, Philip Mulligan, Dominique Nolan

The basic metric for linear shaped charge performance is the amount of cutting distance that the charge can effectively yield given a specific standoff and target. Due to its size and restricted production runs the 10,500 grain/foot (2,232.25 grams/meter) linear shaped charge has had only limited studies that examine cutting performance and standoff. This article covers research regarding cutting performance verses standoff as the charge is applied to common structural steel. Specifically this study uses A36 mild carbon structural steel blocks of 10.16 cm by 11.80 cm by 35.56 cm and standoff distances of 0.5, 1.0, 1.5, and 2.0 charge diameters. Data presented includes the presentation of actual cutting performance numbers, comparison of that data to projected performance based on currently recognized industry guidelines, and a discussion of what may contribute to the performance found in this study.

Jan 1, 2013

By Adrian Moore, Alan Richards

A real-time system for prediction of the effect of meteorological conditions on airblast overpressure levels has been established in the Hunter Valley Coalfield in Australia. Real-time meteorological data from continuously operating sounding equipment and a predictive meteorological model is input to an atmospheric refraction model that enables the effect of meteorology on airblast overpressure levels in the area surrounding the blast site to be evaluated. Graphical outputs from the model, which are superimposed over a scaled airphoto of the mine and surrounding area, show the extent that airblast levels will be increased. When combined with inputs that quantify the effect of blasting specifications, the airblast levels that will result in the surrounding area from the combined effect of blasting specifications is determined. The model permits those responsible for blasting to make more accurate decisions on suitable times that blasting may take place to conform with applicable airblast limits.

Jan 1, 2009

By David E. Siskind

"This report describes recommended vibration monitoring and assessment practices at blasting sites.Intended is regular monitoring, tracking of trends, responding to complaints of alleged damage, and the technical and data aspects of addressing lawsuits."

Jan 1, 1999