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By Ryan Brogden

On the 5 September 2014 a road train (tractor-trailer) with two trailers carrying ammonium nitrate was involved in a single vehicle accident on the Mitchell Highway, 30 kilometers (18 miles) south of Charleville in Central Queensland, Australia. The ammonium nitrate was being transported to a mine site for use as a blasting explosive. The truck came to rest in the creek bed adjacent to a road bridge and caught fire. The vehicle burnt for over one hour before the load of ammonium nitrate exploded. Miraculously there were no fatalities; however eight people nearby sustained injuries, some seriously. The road and rail bridge over Angellala Creek were destroyed and vehicles in the nearby vicinity were seriously damaged. The truck carrying the ammonium nitrate was completely destroyed with over 2500 pieces of debris scattered up to one thousand yards (one kilometer) from the blast site.

Jan 1, 2018

By Ruilin Yang

Based on large amounts of field data, this paper evaluates the validity of the above equations. During the evaluation, the different selections of the frequency in the equations were examined with field data. It is found that when they are used to estimate the vector sum values the above equations could result in large deviations from the values obtained directly from the field measurements or the waveform integration. The simple equations may be used to make rough estimations for single components of blast vibration provided that appropriate safety factors are taken into account. For single component vibration, the principal frequency (from ‘zero-crossing’) seems more effective to describe the blast vibration than the dominant frequency (fron FFT) for vibration peak value estimation using the simple equations.

Jan 1, 2012

By C H. Ryu

This paper presents a simplified two-dimensional numerical model of block fragmentation in a Jointed rock mass during the late or throw stage of a blast after wave effects have subsided. The model is based on the distinct element method. Examples illustrate the approach and allow for a comparison of effects of Joint patterns on fragmentation and resulting block motion.

Jan 1, 1986

By Dale Ross, Bill Clements, Jim Spanos

Current world conditions are forcing the search for "green" energy technology in every aspect of our daily lives. Finding alternatives to petroleum fuels seems to be at the top of the list. The search for the "perfect" alternative is something like the never ending quest of the perpetual motion machine. Unfortunately, the laws of physics prevent us from getting something for nothing, and Murphy's Law normally gives us nothing for a lot of something. Regardless of Murphy, the quest goes on, and in our industry cheaper ANFO seems to be the popular subject.

Jan 1, 2012

This paper examines the hypothesis that the fragment size distribution of blasted rock contains information about the changes in fragment sizes with distance from the borehole, and that this information can be interpreted and used to predict the effect of powder factor on fragmentation. A set of simple relationships between the fragment size distribution curve and the dependence of fragmentation on powder factor is proposed. The equations derived are compared with published data on fragmentation in small scale blasting. Two data sets were analyzed, and the results confirm the hypothesis.

Jan 1, 1997

By Calvin J. Konya

The Woodville Lime and Chemical Company Limestone Quarry is located in Sandusky County, Ohio. Fifty years ago, when quarrying began, it was situated approximately two miles from the town of Woodville. Today new houses border the quarry property within 1,500 feet of one of the working faces. During the past two years, the operation has systematically changed the blasting program to achieve better fragmentation, lower costs, and to maintain good relations with the local property owners. This paper will discuss systematic changes made in the blasting program to increase productivity and reduce costs.

Jan 1, 1977

By V. Sastry

Signgareni Collieries Company Ltd. is operating the JK Opencast Project, at Yellandu, with a rated annual capacity of 1.6 Mt of coal with an average stripping ratio of 4.3. This opencast coal project has three working sections, OC-II block, C-Block and D-Block These workings are operating in close proximity to the JR-5 Longwall Shed, 26-Dip Incline, other structures of 26-Dip, and a Township. There were complaints about ground vibrations and fly rock problems caused due to blasting operations, especially in OC-II and D-Blocks. In view of this, studies were taken up to eliminate the problems of ground vibrations and fly rock.

Jan 1, 2001

By Andrea Brickey, Ethan Marcoux

The South Dakota School of Mines and Technology (SD Mines), located in Rapid City, South Dakota, is one of only a few universities in the United States that offer a Bachelor of Science in Mining Engineering. The Department of Mining Engineering and Management (MEM) at SD Mines teaches courses that introduce students to concepts related to mining, including a course covering explosives engineering. Students are taught the basics of explosives theory and application in the mining and construction industry through a series of lectures and assignments. With limited field experience, many students find some topics difficult; these include: flyrock, ground vibration, timing, and others. Some US mining schools have an experimental mine in which they can simulate field conditions and conduct hands-on training, but not all universities have such facilities. For those without, teaching certain concepts can be more challenging in a pure classroom environment. To counteract the lack of an experimental mine, the mining department at SD Mines implemented Paradigm (Version 18.4.4984.0; McKenzie, 2017) a computerbased blast modeling software to improve the learning environment.

Jan 1, 2019

By Terry Graf, Bill Thompson, John Guenther

SYNCRUDE CANADA LTD.. operates the largest synthetic crude oil production facility in the world. Over 60,000,000 Bank Cubic Metres of oil sand is mined each year from their open pit located in Fort McMurray, Alberta. Despite the extremely cold temperatures encountered during the winter months and the problems associated with frost buildup, SYNCRUDE has continued to operate on a 12 month per year basis. In 1989 SYNCRUDE mine management embarked on a comprehensive Frost Blasting program to improve mine production of their oil sand moving equipment. The following paper will discuss the development of their frost blasting program to its current status.

Jan 1, 1993

By Kevin Dunfield

The Deltadet System is composed of: The Deltadet II electronic Detonator. A Field Terminal to create, modify or simply execute an existing blasting sequence. The radio remote controlled option is composed of a Base Station to program, calibrate and initiate the EDDs plus a Blasting Box to send commands to the Base Station. Blasting lines to connect the EDDs to the Base Station (100m) and Visual Blast software to create or modify a blasting sequence.

Jan 1, 2004

By Jesus A. Pascual de Blas

After 30 years of development and introduction, electronic initiation systems are now well established in blasting applications, both mining, quarrying and civil works. In terms of blast technology, it could be considered that timing is the new challenge: how to define the most appropriate sequence to improve fragmentation, reduce vibrations, avoid dilution, eliminate damage… Some classic tools have been updated and adapted to the new scenario, and are giving us good performance; on the other hand, others should be considered obsolete, given the accuracy of electronic initiation systems has exposed these tools to incoherent conclusions. Besides, other tools have appeared and are in use, providing new approaches to old issues. Additionally, not only the technical side has to be considered: safety, security, economics are well present in daily blasting activity and affect to the final decision: are electronic initiation systems the right answer to my blast?

Jan 1, 2019

By Scott Gustfason, Richard N. Snyder

What is a safe stand-off distance? Recent mishaps using conventional blasting equipment have seen flyrock as distant as 3,750 feet from the blast area, or close to three-quarters of a mile, therefore, whether below ground, under water, in surface quarries or at a structural demolition site, data signals riding a radio wave promise a new horizon for the users of both electric and non electric blasting circuits.

Jan 1, 1987

By Abdel Rahman, M. Khaled, Abo Makarem

There are four large limestone quarries, located nearby Cairo metropolitan. Drilling and blasting operations are used to extract limestone for the cement industries. In these quarries, the blast vibration should be kept below a certain limit. One of these quarries is Tourah Portland Cement Company (TPCC) limestone quarry which, lies near important and historical large caves, within Tourah Mountain. Therefore, control of blast vibration level becomes very critical.

Jan 1, 2007

The use of angled shot holes can be extremely effective in blasting faces that either have a great deal of toe burden or where it is difficult to give a drill access to a face due to backbreak and face erosion. However many quarry operators are wary of using angled holes because of the perceived possibility of increased flyrock and uncertainty of the driller's abilities to drill at the designed angle.

Jan 1, 1994

By George P. Jr Schivley

Data is presented showing Penetration Rate (PR) versus Force-on-the Bit (FB) and Bit Angular Speed (N). Using this data, it is shown how FB and N each uniquely contribute to the PR for any particular drilling situation. This data represents many mining situations; including coal, copper, gold, iron ore and limestone quarrying. The important relationship between Penetration per Revolution (P/R) and the height of the cutting elements of the bit (CH) is discussed. Drill performance is then reviewed, considering the effect of FB and N on bit life. All this leads to recommendations for the operating values of FB and N for drilling situations where the rock is not highly abrasive and bit replacements are because of catastrophic failure of the bit cone bearings.

Jan 1, 1995

By Evan Boone, Peter Bellairs

A technical services visit was conducted to determine the initial parameters to successfully presplit several benches for an input crusher installation at the Wolffdene quarry. The paper details the preliminary design utilising both detonating cord only and specialised presplit product charges and compares these to the final designs utilised based on site experience. The role of accurate drilling, explosive loading and geology in obtaining successful cost effective presplits is highlighted.

Jan 1, 1998

By Roger L. Keller

This paper examines the aspects of differing types of blasting cuts in underground headings with consideration to the reduction of number of holes and costs. At least one comparison study is related where costs per advance meter were significantly improved. The technical aspect of the paper covers a study of the effects of various blasthole delay intervals on resulting crater volume, ground vibration, and fragmentation for six hole V-cuts.

Jan 1, 1989

By Rahim G. Haghighi, Calvin J. Konya

Fragmentation is the fundamental concern of rock blasting and it measures the effectiveness of blasting. Fragmentation is sensitive to not only the interrelationship among the design variables, but also is sensitive to local geology. Local geologic conditions have a significant impact on the success of a blasting operation.

Jan 1, 1986

By A. Cobbii, M. Kasliki, W. Birchi

The Department of Mining and Mineral Engineering at the University of Leeds has a long history of research into the environmental impacts of blasting from quarries and opencast mines. This paper gives an outline of a detailed case study into the structural damaged induced in a rock walled tunnel with a brick lined crown due to close proximity quarry blasting. The test site Taffs Well Quarry is located in South Wales in The United Kingdom and has a disused railway tunnel situated within the south eastern comer of the quarry site. Quarry development plans included the working of this area and therefore the deliberate destruction of the central section of the tunnel.

Jan 1, 2001

By Jeff Wachendorf

Due to the competitive nature of the coal industry we are constantly challenged to reduce costs associated with day to day operations. Every facet of the mining operation is scrutinized for cost reduction and possible efficiency increases. This paper will discuss the pros and cons of two different blasting methods. Buffer blasting has been an institution for many years at Spring Creek Coal and very successful in its application. Cast blasting arrived on a trial basis in 1998 and has produced very encouraging results. This paper will describe the design, drilling, and blasting methods currently used, and a comparison of these two methods.

Jan 1, 2001