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By Chris Uys, Johan Labuschagne

Sishen Iron Ore Mine, located in the Northern Cape, is an open cast mine excavating approximately 100 million tons rock to produce 25 million tons of high grade haematite ore per annum. The size of the pit is approximately 12 km ‘1.5 km ‘150 metres. The final depth is planned to be around 350 metres. It is hard rock mining operation employing the conventional truck and shovel method. Mining benches are twelve and a half metres in height and are divided into blasting blocks, each consisting of approximately 300 000 tons of material.

Jan 1, 1997

By Tom Treleaven, Andrew Williams

The town of Greenwich, CT, an exclusive suburb of New York City awarded several contracts for the installation of sanitary sewer in the North Mianus section of town. The Valley Road section was the most challenging from a rock excavation standpoint. The cut was up to 14 ft (4.25m), with adjacent utilities [20 in. (500mm) water, 6 in. (150mm) water and 8 in. (200mm) gas] located to within 5 ft. (1.5m) of the proposed sewer trench. Rock types varied but were ultra metamorphic in nature, ranging from quartzites, granite gneiss and various types of migmatities.

Jan 1, 2004

By Sushil Bhandari, Amit Bhandari

Blast optimization in open-pit operations is a task that often remains at a theoretical stage. Indeed, when it comes to operational blast design and onsite implementation, time restrictions and field conditions make it difficult to execute a planned pattern accurately and optimization according to local conditions is even more difficult. For example, adjusting a drill pattern to a complex face geometry is not something that can be easily undertaken on site. Blasters and engineers will do their best trying to distribute boreholes over the bench and even then, it can take them hours to achieve an acceptable layout. Similar situations occur with delay sequences, when trying to adjust them to address selectivity or vibration issues. For these reasons, operational blast design will often remain at a very basic level and the required adjustments are laid aside due to the difficulty of implementing them on site.

Jan 1, 2019

By Dale Preece, C. Mick Lownds

Detonation delay timing has been an important aspect of quality rock blasting for decades. Detonators that enable delay timing have improved over the years especially with the recent advent of precision electronic detonators. The positive effects of precision delay timing have been observed repeatedly in the field with improved fragmentation, heave and overall blast control.

Jan 1, 2008

By L C. Taylor, H U. Lesiste

This paper describes a method for estimating the density distribution in the soil cap as a function of distance from its top at the time of impact with the target. It provides an estimate of the density distribution in the soil on the center line of the soil cap at the time of target impact for a single depth of burial of the charge and two heights of target and shows that, for the heights of target and the depth of burial considered, the thickness of the soil cap first increases from the in situ value and then decreases. The distribution of soil density along the centerline of the soil cap changes significantly with distance from its original position. These results can be used for validating hydro-code computations and the soil models used in the computations.

Jan 1, 2011

By Brian T. Burch, Paul N. Worsey

When fired, submerged Linear Shaped Charges (LSCs) lose all effectiveness in the cutting of steel. Users in underwater applications have reported having to substantially increase the charge size to the point where brute explosive force shears rather than cuts the target.

Jan 1, 2015

By Mark E. Hammele

A number of new thoughts have recently emerged concerning the role of air decks, stemming, gas confinement and gross motion in specific blasting environments and applications. Field research in full-scale production environments is based on the theoret ical work f i rst proposed at the Universi ty of Maryland’s Fracture Mechanics Laboratory.

Jan 1, 1989

By Unknown

More than 60 years ago Lakota (Sioux) Chief Henry Standing Bear asked Korczak Ziolkowski to create a monument of Crazy Horse in the sacred Black Hills. Today, you can see Standing Bear’s dream has grown into enormous reality. Crazy Horse Memorial, mankind’s largest mountain carving in progress, is being carved in the round and when completed will be 641 feet long and 563 feet high. Crazy Horse is only 17 miles from Mount Rushmore National Memorial, giving South Dakota unique boasting rights for having two extraordinary mountain carvings in such close proximity

Jan 1, 2009

By M Scoble

This paper will report on the application of data collected through the performance monitoring of large diameter surface rotary blasthole drii and electric mining shovels, in an integrated approach to blast optimizatiion.

Jan 1, 1992

By Ekin Güngor, Berkant Ozdemir, Erkan Bayrak, Serdar Ergün, Sedat Esen

"This paper presents the final wall blasting practices at Eldorado Kisladag Gold Mine in Turkey. Benchmark and improved wall control designs were explained in detail. Kisladag Mine has been implementing a high quality slope stability program on-site. The quality of pit walls is generally considered excellent, with very few wall failures being evident and with presplit hole barrels prominent in most areas of the pit. However, a minor scale slope failure occurred recently at the north-east section the pit. A project was initiated to diagnose the cause of the crest loss and evaluate ways to limit its effect on final walls. Final wall blasting practices and geotechnical designs were evaluated. The work presented in this paper showed that changes to the blasting and geotechnical parameters are required atthe north-east section of the pit. Geotechnical design changes were 10 m bench heights with 70 ° slope face angle at that specific area. Having implemented several geotechnical and blast design changes (elimination of the subdrill for the catch bench, appropriate primer location, more favorable blast tie-up and delays), the crest loss was minimized significantly (<1.5 m) (<5 ft)."

Jan 1, 2017

By Jackson R. Pressley, M L. Hopkins, R E. Danell, N T. Moxon, Andrew Bowman

Efficient and cost effective blasting is achieved by closely matching the explosive energy to the strength of the material in which it is being used. Although there are many empirical relationships wich approximate this situation complete the blast optimization can only be achieved by quantitatively assessing explosive/rock interactions and explosive performance. The performance of an explosive is essentially governed by its velocity of detonation or the rate at which the detonation wave travels through the explosive column.

Jan 1, 1991

By Robert Lee, Pertti Paavola

Automated vibration monitoring and web-based data distribution has proven itself on the largest single construction project ever undertaken in Finland. The excavation for the Kamppi Center Project in the center of Helsinki was completed in November of 2003 and involved the removal of over 200,000 m3 (260,000 yd3) of rock and over 1,700 individual blasts. A system was installed, incorporating 37 discrete monitoring points located throughout an underlying metro station, and other surrounding underground and surface facilities. After every blast, vibration data was automatically transferred from the monitoring network to a server database. Stakeholders were able to access and review vibration reports on a password-protected website within 90 seconds of each blast. This allowed engineers to verify that recorded levels were in compliance with established limits, before proceeding with subsequent blasts. The data was also imported into a semi-automated Scaled Distance tool for analysis using linear regression techniques. This was used to determine, and adjust for trends in blast-induced vibration.Copyright

Jan 1, 2004

By George Boucher, Simon Williams, Neil McBride

"The aim of these analyses was to utilise the latest available production information for the Wandoooperation to determine the optimal blasting parameters, costing’information and predicted results(fragmentation, muckpile shape and vibra.tton). Much of the data used as input was made availablefrom the information gathered during the excavation of the test pits during 1995. As with any“planning stage” analyses, many assumptions were required to fill gaps in the available data."

Jan 1, 1998

By Robert Martin, Brian W. Stump, David P. Anderson

2We use field measurements to quantify physical processes that accompany different types of mining explosions. The data sets collected include three-component ground motion, acoustic, video and high speed film, three dimensional topography, geological and geophysical properties, design blast pattern and timing, and velocity of detonation in the explosive for individual borehole detonation times. The explosions include simple single-fired contained explosions, ones designed to bulk and fracture material and those that cast material. Our goal is a physical understanding of these sources for the purposes of optimizing blasting practices.

Jan 1, 1998

Since the ecrly 1970's several factcrs have changed. In the East the larger tracts of coal mined with large eauipment are being dePleted, The cost of moving the larger equipment from small tract to small tract becomes eccnomicallv unattractive, Conseauently, the tracts are being mined with smal!er draglines or with loader/truck haulage combination, This has resulted in a major increase in the cost of moving a cubic yard of overburden,

Jan 1, 1989

By Steve Colburn

The CRITERION Survey Systems utilize both theodolite mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environments characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, Windows-based, interactive software program which can be run on’ any standard PC.

Jan 1, 1998

By Ralph Dawson

The following additions to SLP-4 “ALWAYS AND NEVERS” have been approved by the Board of Governors since the last printing 6/97 and will be included in the next printing soon. They are also included in the Second Printing of the 17th Edition of the ISEE Blasters Handbook. Review them and apply those which might be applicable into your blasting program now.

Jan 1, 2001

By John A. Franklin, Tom C. Palangio, Norbert H. Maerz

WipFrag systems I and II have become the world standard in photoanalysis systems to measure fragmentation. Mines, quarries and excavating contractors can now easily measure blast results and track the progress of optimization efforts. This technology was developed and evolved to allow automatic measurements of the size distribution of patiicles on moving conveyors, in truck boxes and on crusher feeds. Production machinery can now be controlled by photoanalysis results and multiple cameras allow various locations to be monitored by a single system. Blast designs can be monitored on a shot by shot basis. Changes in delay times, explosives, patterns and hole sizes can be quickly evaluated. Along with this measurement capability has come a heightened awareness of the importance of “optimum size” and uniformity of particles for lowest cost production and material handling efficiency. In the past, savings in the “drill / blast” cycle of the operation were sometimes overshadowed by downstream production costs related to fragmentation. Now total production costs can be compared with fragmentation sizes which will immediately show the trend towards optimum size for economical production. No cost reduction program can be complete without this critical information.

Jan 1, 1997

By He Guangyi

Combining living examples, the paper introduces the controlled chamber standing shot of more than 3000t explosives initiated at one time with Nonel under complicated circumstances and the experience obtained to keep environment safe and favour mechanical rock cleaning.

Jan 1, 1998

By L C. Taylor, H U. Lesiste

This is a preliminary study of the statistical variation of the pressures on a target above a buried explosion. The data were taken at various distances from the charge centerline for three heights of the target above the soil and one charge depth of burial. All tests were conducted in saturated sand. They show that peak pressures and times of peaks are neither repeatable from shot to shot nor rotationally symmetric within a single shot. The peak pressure and time of peak at each location can be represented by cumulative normal distributions. The paper describes the means and standard deviations of these distributions at eight distances from the charge center for each height of target. These are used to determine the change in standard deviation of the distribution with distance from the charge centerline and height of target. The effect of scale on the mean peak pressures and times of peaks and on their standard deviations at a single scaled distance from the centerline of the charge are explored using various charge weights.

Jan 1, 2010