Search Documents

By Ran Tamir

"This document introduces the use of drone generated aerial photography to collect and analyze fragmentation data for both muck piles and post crusher stockpiles in order to support the continuousimprovement process. In tandem with photo analyses software, drone imaging gives mines and aggregate sites a fast, accurate and economical method of benchmarking and optimizing the process of size reduction to spec."

Jan 1, 2017

By Joseph Trocino, John Anderson, Stephen Murray

This paper describes the development of LEXFOAM® (Liquid EXplosive FOAM) as a unique low density explosive, and its successful application as an effective tool for "in-place" demolition of landmines and unexploded ordnance. Explosives research using aerosol technology led to the development of LEXFOAM whose components are safely transported and stored as flammable liquids. These components are mixed on site to produce an explosive foam, which enhances safety and minimizes logistical problems. Hand-held, Backpack and Palletized Delivery Systems form a versatile family of dispensing systems to suit any application.

Jan 1, 1998

By Roberto Golchi

This article describes the method used to quantify the Environmental Impact for the mining, by drilling and blasting, of a borrow pit for a gravity-dam. The affected environment was broken down into a number of components, such as public health and safety, social relationship, air and water quality, flora and fauna. The effect of the various impacting factors from the mining activities, both directly and indirectly, was then calculated for each environmental component. To do this, each impacting factor was first given a magnitude, a number based solely on the range of scenarios possible for the impacting factor. A matrix of weighting factors was then derived to systematically quantify, and normalise, the effects of each impacting factor on each environmental component. The overall impact upon each individual environmental component was then calculated by summing the weighted magnitudes for all the impacting factors.

Jan 1, 2003

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high speed photography to better understand the mechanisms of fracture and fragmentation.

Jan 1, 2015

By Carlos Enrique Arroyo Ortiz, Jadir Pedro Alves

This paper presents some of the results obtained during the research work about the use of technologies and digital transformation in the process of rock drilling in open pit mines. The use of automation presents itself as a disruptive factor and a driver of improvements that provide sustainability in rock drilling. Seven main operational parameters were utilized to combine measurement while the drilling (MWD) with other information generated by the equipment during hole drilling, in six different lithologies in an iron mine, located in the central region of Minas Gerais in Brazil. Adjustments and corrections were made to the data collected in order to minimize external influences other than the rock itself, to ensure the effectiveness of the analyses. Finally, we sought to compare the performance of the drilling process in manual and automatic operation modes. Thus, making it possible to show the efficiency and impact on the sustainability of rock drilling operations in open pit mines.

Feb 6, 2023

By E. Vilaescusa, J. Eloranta

The work presented in this paper investigates the influence of non-ideal detonation characteristics related to the blasthole diameter, base emulsion sensitivity (micro-balloon sensitised versus unsensitised) and percent emulsion on the explosive shock energy available to break rock using ANFOemulsion blends. A series of theoretical equal powder factor bench blasting patterns with hole diameters of 127mm (5”), 140mm (5.5”), 152mm (6”) and 165mm (6.5”) are compared to assess the non-ideal confined shock-state work energies. The Non-Ideal Shock Energy Factor (NSEF), which is the available shock energy per cubic meter of blasted material (MJ/m3) or kilocalories per cubic yard (kcal/yd3), is used to compare the different blasting patterns charged with a range of ANFO-emulsion blends from zero to 50% emulsion.

Jan 1, 2012

By David R. Ziegler

The concept and facts concerning "threshold blast damage" are not considered "general knowledge". Perhaps because of a lack of knowledge, understanding, and experience of blasting effects, property owners and lay-persons may attribute a wide range of common cosmetic conditions to "blasting damage".

Jan 1, 1997

By Nick Lewis, Paulo Pereira

The Vulcan McCook quarry has been in operation for about 100 years. It is located about 17 miles from downtown Chicago and is surrounded by both industrial and private structures. Recent issues have forced the quarry to blast very close to structures and this will be necessary years into the future. This paper discusses the implementation of electronic detonators to McCook. It also discusses the advantages and savings that the Program has achieved

Jan 1, 2003

By Thomas M. Keevin, Gregory L. Hempen, David J. Schaeffer

In an attempt to reduce the potential for fish mortality during the explosive demolition of Locks and Dam 26, Mississippi River, the U.S. Army Corps of Engineers, St. Louis District explored the use of a bubble curtain to reduce the fish kill radius of underwater explosions. Bubble curtains are walls of bubbles rising from a bottom-resting bubbler manifold supplied with compressed air. Demolition engineers have long been aware of the attenuating properties of air bubbles in water. As such, air curtains have been routinely used to protect underwater structures from damage by underwater explosive shock waves. However, their use in protecting aquatic resources during full-scale explosive demolition projects was untested.

Jan 1, 1997

By Paul Sterk

In underground mining a great deal of time, money, effort, and resources have been used in the effort to minimize blast-induced damage. This damage occurs to the back, ribs, and pillars when the energy of the explosive is released back into the rock due to over confinement or the overloading of explosives in the perimeter holes. This damage can result in roof falls, dilution of ore, excessive rock bolting, scaling, screening, shot-creteing and other safety and support issues.

Jan 1, 2003

By Dale Ramsey

Emulsion explosives have become the product of choice for many blasting applications and are not limited to just extreme wet hole conditions or special application environments as in the past. Today’s novel emulsion technology has evolved over many decades, allowing a great diversity of formulations, Emulsion explosives can be effectively designed to produce very high energies, cap sensitive high explosive cartridges to bulk blasting agents, with varying viscosities, stable VOD’s, excellent water resistance, long shelf life and sleep time. They are also conducive to the mixture of emulsion, An/F0 blends in varying proportions and are amenable to any type of sensitizer. The key to a stable, reliable and consistent emulsion formulation is the careful mixing of the internal phase, which consists of a solution of oxidizer salts suspended as microscopically fine droplets, with the surrounding continuous fuel phase. There are few blasting applications today where some form of an emulsion explosive cannot fit the application. In massive, hard rock, dense, tightly jointed and fine grained rock types, the emulsion explosives are the best choices in creating new fracture networks for good fragmentation with a few alternatives. In such environments, emulsions with expanded drill patterns often result in better economics than the use of straight AnLFo. This paper will cover emulsion formulations, sensitizing options, product testing, material handling, and blast optimization, Emulsion explosives characteristics have also proven to reduce adverse environmental effects such as noxious fumes, ground vibration, and airblast while still remaining cost effective.

Jan 1, 2000

By Visitor Makiyi, Chris Batten

Poor coal recovery due to coal damage or loss caused by blasting can have a significant impact on a mining operation. Increasing coal recovery by reducing blast damage can provide a significant opportunity for coal mines to maximise their revenue and reduce their operating costs. This paper provides details on advanced drilling and blasting techniques used throughout the coal industry globally to prevent coal damage and movement during blasting. Typical coal loss and damage mechanisms are explained, along with how each of the applied techniques works to minimise the impact of each mechanism. Key requirements for a coal loss reduction program are detailed with typical design parameters used for each of the methods discussed. The positives and negatives of each method are also provided to enable comparisons and help determine suitability for a particular coal mining operation.

Jan 21, 2025

By O Omidi

Selection of delay times to optimize fragmentation has been a controversial topic among researchers and blasting practitioners. This paper reviews previous experimental information and presents the results of new tests conducted in small blocks constructed using a commercial grout. The effect of the delay on the average fragment size, coarse fragmentation and uniformity of fragmentation is discussed. Fragmentation was coarser at extremely short or extremely long delays, while a fairly constant average size was obtained at a variety of intermediate delays. Uniformity, defined as the slope of the fragmentation distribution through the average fragment size, was poor at short and very long delays and relatively constant at the intermediate delays. Some tests attempted to minimize the effect of gas penetration by lining the boreholes with copper tubes. When this was the case average fragmentation changed marginally, while uniformity was significantly affected by delay and was typically smaller than in the unlined tests.

Jan 1, 2014

By Jhon Silva-Castro, Russell Lamont

Understanding the behavior of materials subjected to high strain rate conditions is of fundamental importance to the mining industry. Several stages of the mining process involve high speed loading rates including blasting, scraping, comminution, etc. Technical comprehension of how rocks deform, fracture, and fail under these loads is a fundamental first step required prior to any serious attempts at optimization of the energy utilized for pertinent activities in the mining process. A Split-Hopkinson Pressure Bar (SHPB) was designed and constructed at the University of Kentucky to study the dynamic properties of various types of rocks.

Jan 1, 2017

By Yong Pan, Purushotham Tukkaraja

It has been well understood that blasting is the cost-effective method for breaking rocks as compared with the mechanical systems. However, vibrations induced by blasting in open-pit mines could pose problems to the structures surrounding the mine site. Blast-induced ground vibration has been the subject of research for several studies in the past; because of the complex nature of blasting mechanism, it is difficult to predict blast-induced vibrations. Even though there are several approaches proposed by the previous researchers, traditional regression analysis is still playing an important role in predicting blast-inducedgroundvibrations.

Jan 1, 2019

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 Tristan Worsey, Brad Gyngell, Todd Buschjost, Gus Diehr

This paper highlights the opportunities provided by integrating MWD data and drone generated 3D model to industries that use explosive energy to perform useful work as an integral part of their rock extraction process.

Feb 1, 2020

By B. Papilon

Dynamic pressures during blasting can affect performances of both electronic and non-electronic detonators. Boreholes can develop tremendous amount of pressures during blasting. The effect of such elevated pressure especially during electronic delay countdown is probably more acute in electronic detonators. Measuring the pressures during blasting can aid to understand the relationship between magnitude of the pressure developed and the multitude of blasting conditions.

Jan 1, 2013

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 I. Petrovsky

Presence of the ground water, especially flowing water, causes limitations in the type of the explosives, which can be used for the blasting development in the open cats and quarries. This presents really big problem in Russia, because more than 70% of the blasting holes are wet and filled by flowing water. The waterproof explosives need to be used in these conditions, which increases the cost of the blasting development. So the search of the methods to remove the water from the blasting hole and to prevent direct contact of the explosive material with the water is important. It will give possibility to use nonwaterproof explosives (such as ANFO) and decrease the cost of the blasting development.

Jan 1, 2003