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By Jeff Friedman

This paper addresses certain problems to be encountered when a blasting contractor agrees to provide indemnification. Nearly 100% of all blasting work is performed pursuant to a contractual agreement. Whether the explosives engineering firm works directly for the property owner, or for a general contractor by way of subcontract, indemnification agreements are generally required to protect owners, operators, general contractors, and other interested parties in the event there is subsequent litigation. These contractual requirements are typically referred to as indemnification and “additional insured” agreements. We will address the ramifications of contractual indemnification as well as “additional insured” agreements in this presentation. Some of the aspects of this paper will include:

Jan 1, 2004

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 H. Mullani

We have in southeast Kansas a variety of soils underneath which are a variety of subsoils compressed into what is commonly called “ hard pan.” These soils are of six types, ranging from a clay to a sandy loam. The surface soil in Cherokee County and Crawford County, of whatever quality or type is, generally speaking, from 6 to 12 inches in depth. The so-called “hard pan” ranges from the native grass roots to a depth of from 2 to 12 feet, and in some places even deeper than that.

Jan 1, 2010

By Tristan Worsey

This work was performed during the summer of 2008 during the junior year of a BS in Mining Engineering. It was observed that the mine was having a problem with back break during the blasting of development drifts. The unwanted back break was causing the mine extra costs in ventilation, ore dilution, ground support, back fill, explosives and man-hours. The blasting practices were observed for four weeks and the problems and their solutions were defined. In this paper the reasons and causes of the problem are explained with the proposed solutions to eliminate back break.

Jan 1, 2010

By Douglas A. Anderson

The US Bureau of Mines, in RI 8507, has shown that blast vibrations at low frequency are more likely to cause damage and complaints than those at higher frequency. Since that publication in 1980, the Office of Surface Mining and many state and local regulatory authorities have incorporated frequency in their regulations for acceptable ground vibration from blasting. Even when frequency is not explicitly stated in regulations, it may become an issue in hearings or in court.

Jan 1, 1992

By A B. Opperman

For many years explosives energy has been utilized in mining and construction as well as many other applications which are vital to our way of life. Many types of explosives have made their contribution as technology has moved forward. One of the best known was dynamite, which for many years was the mainstay of explosives users. Although dynamite had many advantages over its predecessors, it had the principal shortcomings of being somewhat hazardous to handle and was known as a headache producer.

Jan 1, 1975

By Ulrich Leiste

If the iron ore loss is 15% in the process of mining, the total iron ore loss in the world will be about 461 million tons, this is equal to the total production of 230 iron ore mines each of which produces 2 million-tons of iron ore per year. Based on a series of blast tests in the Malmberget mine, this paper shows that ore recovery can be markedly increased by improving blasting technology such as choosing a correct primer position and making use of shock wave collision. The paper further suggests that a high ore recovery can not only reduce natural resource loss and mining cost but also prolong the life of a mine. In addition, the paper shows an example of reducing blast-caused rock damage in the roofs and walls of underground drifts (tunnels) by using new blasting methods in the Malmberget mine. Finally, the paper shows how the Malmberget mine has successfully reduced the ground vibrations, without adversely affecting fragmentation and ore recovery in sublevel caving mining.

Jan 1, 2014

By Tacio Ferreira

How state-of-the-art software, data analysis and communication applied to drilling and blasting techniques have have allowed quarries in the Midwest of the United States to improve results downstream

Feb 1, 2020

By Carlos Campos Junior, Leonardo Soares Chaves, Raul Carretero Hoz, Renato Jacome Costa, Davi Bastos Martins de Oliveira

The Vale’s Serra Sul mine, also known as S11D project, is one of the world’s largest open pit iron ore mines, located in Brazil’s Amazon region. The mine produces around 90 Mt of high-quality iron ore annually. Its unique orebody enabled the S11D project to adopt a truckless mining system with In-Pit Crushing and Conveying (IPCCs) for ore exploitation and waste stripping. The IPCCs system requires crushing the waste, mainly composed by the jaspilite lithology, and is also conveyed to waste deposits several kilometers away from the mine. Due to Amazon’s environmental restrictions, the project was designed with preliminary geological knowledge, leading to the installation of primary crushers not designed for the hardest jaspilite, with uniaxial compressive strength (UCS) up to 500 MPa. This resulted in low waste crushing performance, affecting stripping ratio and threatening future production. A project was developed to improve the fragmentation of the jaspilite, allowing higher waste IPCC production, and reducing the risk to the production due to low performance of waste crushing and conveying. The first challenge was the independence of the geological and the geomechanical models, while only the geological model was considered in blast designs, the geomechanical model describes six waste groups of jaspilite classified according to their strength. A new geological model was then created to incorporate the geomechanical classification, allowing different blasting design according to the rock strength of the jaspilite. The blasting pattern on most compact jaspilite was reduced 27%, from 22m² to 16m² in 9 7/8” diameter holes, with a proposed theoretical reduction of 23% of the P80, from 326mm to 250mm. The second challenge was the implementation of the new design, as this pattern size and the high powder factor (2.9 kg/m3) were paradigms for such a large iron ore mine. The measured results have shown 25% reduction of the P80, the crushing rate was increased by 17% (230t/h), saving around $2.4 million annually in crushing and conveying system maintenance.

Jan 21, 2025

By Patrick D. McLaughlin, C Fordham

"The project outlined in the accompanying paper was to densify beach sands on the pond side ofa tailings dyke to the strength required for future dyke construction, This was to be achievedthrough the detonation of relatively small explosive charges in the sand to cause settlement intoa denser state."

Jan 1, 1992

By Jeon Jeon, Yong-Kun Choi, Chung-In Lee, Yong-Hun Jong, Hag-Soo Kim

In this study, a computer program to design tunnel blasting pattern has been developed. The program consists of two parts; one is for tunnel blasting pattern design and the other is for blasting modeling to estimate the peak particle velocity, the distribution of fragmentation and the excavation damage zone. We modified the design method of tunnel blasting pattern suggested by Langefors because it provided undesirable pattern in blasting practices such as considerably large center cut and too large burden for Vcut as drilling length increased. As a result, the burden and spacing were reduced to practically appropriate amounts. In addition, the correlation between rock mass rate, RMR, and rock constant in blasting, c, was analyzed based on the data collected from twenty three tests of tunnel blasting. It was concluded that the correlation between them was fairly good enough to be applied in cut design. In order to check the validity of the modified methods and their practical applicability, test blasting was carried out at two different tunnel construction sites in Korea. The results were satisfactory in that the average rate of advance was 90% and the overbreak did not cause additional support. Futhermore, the developed program is capable of estimating peak particle velocity by using (a) the existing vibration equations, (b) the vibration equation obtained by test blasting to check out the practical applicability of the designed blasting pattern. Feedback is implemented into the program to adjust the designed blasting pattern and control the vibration.

Jan 1, 2005

By J. Silva, T. Worsey

The Worsey-Silva equation determines the optimal row timing for the smallest fragmentation and allows fragmentation models to be adjusted due to row timing. The equation utilizes the concept of dynamic confinement to determine when the best time to fire the next row or sequence series would be if the smallest fragmentation is desired. Full-scale testing was conducted at an aggregate quarry in Ontario to support the theory and equation. The full-scale testing comprised six (6) blasts, two (2) different contractors, and three (3) different sequences. The test parameters were kept consistent, besides changing the timing between sequential charges to explore the timing sequence’s influences on fragmentation. From this research, the theory of dynamic confinement relating to row timing was discovered, and the equation to determine the optimal timing for the smallest fragmentation was derived. An equation to adjust fragmentation based on row timing was derived from the full-scale testing and literature review. The Worsey-Silva equation can be used with other fragmentation models as it takes the fragmentation results from the other models and adjusts them based on the row timing used. The paper explains the theory behind the equation, the research supporting the findings, and the developed Worsey-Silva equation for row timing

Jan 1, 2024

By NA NA

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Feb 6, 2023

By Roberto Folchi

This note deals about the controlled demolition work for the dismantling of an industrial structure in San Seplocro, Italy. The structure to be demolished, the FLOWERS SILOS, consisted in a multilevel reinforced concrete frame supporting r.c. silos and steel silos. This was standing near civil buildings and was adjoining a warehouse that had to be safeguarded for being renewed.

Jan 1, 1994

By John M. Bolger, Keith E. McMaster

Excessive salt fines are undesirable in underground salt mining as they are considered a costly waste byproduct. This paper describes an extensive explosive application program conducted at The Canadian Salt Company Ltd, located in Pugwash, Nova Scotia, Canada. The prime objective of the program was to reduce the quantity of fines generated from this company’s underground production blasts. The program was known as the “The Fines Reduction Program”.

Jan 1, 1996

By Frederick B. Kuhnow

Harmonic energetic delamination a building is being considered for demolition at a formerly known atomic power lab. The building is within a containment structure under a negative pressure, so that no radioactive material is leaked out to the environment. A new approach was developed to make this work possible.

Feb 1, 2020

By Michael David Wilkins, Paul N. Worsey

Little research has been published on stemming blast holes, particularly what happens during the process. Previous work has concentrated on the performance of the inert material to find the best way to seal the hole and retain the explosive energy, at the exclusion of determining what happens during the loading and stemming process.

Jan 1, 1998

By Robert Jacob Cefalo

In 2019, the Bingham Canyon Mine, owned by Rio Tinto Kennecott Utah Copper Company, mined through the active underground that dewaters the pit. The active underground required the limitation of vibrations to avoid catastrophic damage or damage that would require work to the shotcrete and additional roof support. The surface design of the current sector was mined next to and through portions of the active underground.

Feb 1, 2020

By Paul Downing

When was the last time the documents and paperwork were cleaned out of the glove boxes, door pockets, under the seats and above the visors in your company vehicles? Insurance cards that expired three years ago and vehicle registrations from 1999 through 2003, for instance, don’t do any good and just take up space

Jan 1, 2008

By Darcey Baker

Quarry Blasting is usually boring, and that is how we like it. By this, boring means routine, straightforward, meat and potatoes blasting. Quarries typically will not utilize cast blasting, coyote tunnels, or any of the other more spectacular blasting techniques – just plain, old day-in and day-out quarry production and possibly overburden blasting. Differences in material characteristics, mining method, equipment availability, and target markets all play a part in determining the blasting procedures employed at any given location. However, variables exist everywhere and with foresight and planning, effects of tangible variables can be minimized. Variables caused by geology, weather, neighbors, or limitations caused by major plant or mobile equipment are, generally speaking, intangible; and leave the operator with finite options to improve or modify blasting procedures.

Jan 1, 2009