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By Finn Ouchterlony

"Recently detailed fragmentation data from blasts fired with electronic delay detonators (EDDs) in the Red Dog mine in Alaska were presented. They include a comparison with pyrotechnic detonators fordifferent in-­-row delays in a standard pattern and EDDs in an expanded pattern. Fragmentation was measured on the belt after the primary crusher. The Rosin-­-Rammler function (RR, two parameters) was used to describe the crusher product. This was combined with the JK SimMet crusher model and the CZM blast model (Crushed Zone Model, three to five parameters) to estimate a reasonable crusher feed (muck pile fragmentation or run of mine, ROM) for each fitted product. In this way the effect of delay timing and electronic detonators on the median fragment size x50 and uniformity coefficient n for both crusher product and the blasted rock was determined. "

Jan 1, 2012

By Michael Karmis, Syed Muhammad Tariq, Zeshan Hyder

Secondary or boulders blasting is a regular feature of quarrying operations in Pakistan, especially in cement and stone crushing industries. The main reason for secondary blasting is the production of a large number of boulders during the production blast. These boulders are larger than the feed hopper of crushers and require further breaking. The complex geometry of boulders, relative lack of restraining burdens, and the availability of number of free faces make this kind of blasting more hazardous than production blasting. Secondary blasts have generally unpredictable results and may cause flyrock, airblast, and over-crushing of rock material. Thus, it is essential to have an appropriate amount of explosive charge/powder factor, and for it to be properly distributed in the blast hole. The greater the amount of explosive over the required amount, the more violent is the blast, which will result in more flyrock, airblast, and excessive crushing of boulders.

Jan 1, 2012

By Daniel Vargas Quispe, Yorhinio León Robles, Marco Jauregui Vargas, Helen Espinoza Bailon, Oshin Quispe Luya

This project describes the methodology applied during the execution of tests to determine the multiple controls that mitigate damage to the final walls of the pit. The different tests were executed on production pattern, which considered: modification of the angle of pre-split drill line, damage evaluation in individual drills with different load designs, varied detonation sequences, capture and analysis of elementary waves. After the evaluation and analysis of the results obtained in the tests, we are in process to standardize various damage controls such as; the combination of pre-split drill line angles at 80° and 90°; charge design in buffer drills that reduce the angle of action of the explosive and a detonation sequence that involves the creation of a relief filter that is made up of the detonation of two rows next to the pre-split drill line, which will have the function of filtering the waves of vibrations produced by the detonation of the production drills and at the same time it modifies the direction of damage towards the blasted material. The analysis of the different controls, as well as their combination, will allow us to improve the compliance results of the formation of benches.

Jan 21, 2025

By Tyler Rockley, Carla Reyes

Autonomous fragmentation measurement systems designed for shovels have been in operation for nearly two decades, however fragmentation systems capable of performing in the dynamic conditions of the front-end loaders (FEL) were only recently introduced to the market. This paper presents an in-depth evaluation of an automated digital fragmentation measurement system specifically designed to perform under the dynamic operational conditions of the FEL in two of Teck’s mine sites. As early adopters of this novel application, Teck embarked on a Proof-of-Concept (PoC) trial phase, defining a set of key performance indicators (KPIs) to qualify the performance of the digital solution in tough mining operating environments. The KPIs focused primarily on the hardware robustness, quality of image and segmentation, both day and night, availability of the system and sample ratio. The benefits expected from using this technology include increasing the safety of the current fragmentation measurement process, improving the quality of the analysis, increasing the sample representativeness, and using the attributes of the system to create an oversize detection alert to inform the loading operation process. A critical part of the evaluation was verifying the system’s effectiveness on the particle segmentation algorithm as this element often gets overlooked, especially when dealing with the large number of samples autonomous systems can generate; minor misclassifications due to inadequate segmentation are often dismissed as they might not be statistically significant, however systematic misclassifications can cause unacceptable deviation in the data and limit the intended application of the technology. The system’s performance was further validated through several tests that involved identifying objects of known sizes to ensure the reliability on the consistency of the particles’ segmentation.

Jan 21, 2025

By Eric R. Achelpohl

The paper follows the introduction of a college student into the explosives industry. The opportunity of experiences from classes and work at the University of Missouri-Rolla, along with summer internship experiences are highlighted.

Jan 1, 1998

By C. B. Navalkar

The optimization of blast design under consideration is for the conventional driveways in under ground coal mines with respect to board & pillar workings in India. Basically The Blast Design includes following parameters: AA> Drilling Pattern. BB> Charging Pattern. CC> Material & Method Of Stemming. DD> Selection of type & quantity of explosives. EE> Initiation system & Blasting Sequence.

Jan 1, 2002

By J MacPhail, H Gardner

This paper discusses reasons why users of rotary air blast hole bits encounter premature bit failure due to bearing failure. It also discusses a lubrication system designed for rotary rock bits to combat bearing failure.

Jan 1, 1996

By Mike Cammack

Western South Dakota is predominately an agricultural area, with exception of the mining and timber industries in the Black Hills region. With precipitation rates averaging below fifteen inches per year, water is a precious commodity to the livestock industry. There is a constant demand for the construction of earthen water storage facilities (dugouts) to catch snow and rain runoff, or developing natural springs.

Jan 1, 1993

By A Lance McAnuff, Andrew Curic

Until relatively recently, underwater blasting operations for channel deepening, dock construction and pipeline crossings of lakes, rivers and streams were conducted without much regard for the potential side-effects on aquatic organisms.

Jan 1, 1997

By Winfried Rosenstock

Following successful trials at Chuquicamata / Chile from February to May 2000 and from February 2001 onwards at Burton Coal Mine, RAG International/Thiess Pty Ltd., Queensland / Australia a significant advancement in blasting technology was achieved using electronic detonators. The mine now uses electronic intiation for the majority of overburden blasting.

Jan 1, 2002

By Patricia Mendoza Watson, Lundquist Robert G

The velocity with which the burden moves after blasting is of concern for safety and economic reasons. Models developed for motion velocity by various researchers were reviewed and likely model parameters were used to develop statistically significant models. Regression analysis and residual analysis were used to determine the model coefficients and the accuracy of the models.

Jan 1, 1990

By David Davison, Richard Johnson

Metal-oxidant blends are ordinarily unsuitable as diiect replacements for explosives, because the reaction occurs too slowly. Oxide coatings protect metals, preventing or delaying reaction. By contrast, the electrically-activated reactive composites described below are configured as metal fibers or foils in close proximity to oxidants, with continuous electrical paths from one end to the other. By quickly vaporizing the metal component with an electrical pulse, a reactive composite will be activated, and the reaction will occur rapidly.

Jan 1, 1999

By Sharon K. Reamer, Yvan Sifre, Klaus-Gunter Hinzen

"Three case studies are presented that illustrate the successful application of firing timeoptimization (hybrid modeling) in the quarry environment and for a construction site. In allcases, the method requires the measurement of at least one in situ, single hole explosion asa representative model of the desired blast design."

Jan 1, 1993

By W. Reisz

Blast area security is the responsibility of everyone involved in the blasting operation and goes well beyond simply controlling access by unauthorized personnel.

Jan 1, 2009

By O E. Crenwelge

Seismograph measurements are usually made near blasting operations solely for the purpose of monitoring compliance with governmental regulations. However, recordings of seismograph signals have far greater potential than this, if the proper procedures are used for analyzing the transient data.

Jan 1, 1991

By J P. F Warkentin, A W. Bauer

Recently, significant improvements have been made in both blast design methods and blasting accessories. The introduction of extremely accurate blast delays now allows proper implementation of advanced blast designs. Thus the onus for future blasting improvements has moved from blast design to the need for ensuring that explosives quality is of the highest order. One measurement commonly used to assess explosive performance is the velocity of detonation (VOD).

Jan 1, 1991

By E. A. McCullough, Jackson B. C., S. K. Metz

Public perception is a significant challenge facing the explosives industry. The public often perceives that its needs and interests are in direct competition with those of blasting companies’, leading to conflict between corporations and the community. This misunderstanding lends to unnecessary political and regulatory hardship, and ultimately, social discontent. Although individual corporations implement strategies to address conflict, many of these techniques are insufficient. Consequently, stakeholders resort to expensive litigation. If blasting companies could reduce or eliminate the volume of judicial disputes, valuable resources could be re-directed to more productive activities.

Jan 1, 2015

By Shulin Nie, Mats Olsson

The mechanism of rock fracture by explosive is a fundamental in rock blasting. It is generally believed that the shock waves from the detonation initiate the fractures. Then the detonation gases penetrate into the fractures and elongate them. However, our previous researches indicated that the detonation gases do not contribute significantly to the fracture propagation. In our latest experiment, blasts have been carried out in 8 large granite blocks. The main goal was to study the fracture mechanism, namely to determine whether the shock waves or the detonation gases fracture the rock.

Jan 1, 2001

By Rahim G. Haghighi, Calvin J. Konya

Fragmentation is the fundamental concern of rock blasting, serving as a measure of blasting effectiveness. Fragmentation is sensitive to the inter-relationship among the design variables which define pattern geometry. Therefore, the objective of this study was to develop a model which represented a confined bench blast and to investigate the movement of burden-rock as the length to burden (L/B) ratio was varied.

Jan 1, 1985

By Chang-Ha Ryu, Hyung Yang, Hyung-Sik Yang

Ground vibration by rock blasting causes many environmental problems to adjacent structures and human bodies. Growing concerns have been given to the effects of dynamic loading induced by blasting works near safety-related structure like nuclear power plant, hospital, broadcasting station, research institute and tish farm, etc. In order to ensure the safety, rational safe criterion should be established. It requires development of a model to predict the design parameters through more systematic measurement and analysis. Primary estimation by adequate model with general parameters will be very useful for safe design and understanding the possible hazards in advance.

Jan 1, 2001