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By Michael S. Stern, Gordon P. McDonald

The increasing costs and problems associated with transporting and safely disposing of used engine oils from remote mine sites have caused mining companies to consider other ways to consume their used oil. One practical method of disposing of these used oils is to blend them with the diesel component of ANFO and Heavy ANFO type explosives.

Jan 1, 1993

This paper describes experience in designing and implementing casting blasts over the past fifteen years. Important design parameters such as powder factor, burden and spacing, blast pattern geometry, front row burden and toe distance, pit width versus height, blast length, explosive selection, millisecond delay timing and tie-in types are discussed.

Jan 1, 1995

By Sarma Kanchibotla

In mineral industry operations the insitu ore is’separated from the waste rock and is subjected to a series ofprocesses to convert it into a valuable product. Profitability of any operation in this industry depends on how eficiently the insitu rock (ore -I- waste) is converted in to the final product and how much value @ice) it commands in the market. Traditionally, the total process in mineral industry is classt@ed into two groups as mining and milling, and optimised independently without considering the impact of one over the other. This paper investigates the impact of mining operations (especially blasting;) on downstream processes and demonstrates the potential benefits of the “Mine - Mill Blasting” approach through simulations and case histories.

Jan 1, 2000

By Eraldo Florêncio, Paulo Couceiro, Manuel Lopez Cano

Specialized marine blasting techniques were required to deepen and widen the access channel and turning basin of the Sudeste Port Terminal in Rio de Janeiro, Brazil. This terminal has been designed to handle the exports of iron ore and other bulk solid cargoes to international markets. The Sudeste Port Terminal is connected to the iron ore quadrangle in Minas Gerais State by a dedicated railway line, giving Brazil’s independent miners a seamless access to global markets. However, the Sudeste Port Project is located in a protected marine environment. Blasting in this area has required a comprehensive blast induced ground vibrations monitoring and analysis program to ensure the safety of the sensitive structures surrounding of the blast areas. Nevertheless, the risk of generating higher ground vibrations on nearby structures due to the combination of short distances, larger excavations layers and complex geology, increased the complexity of the blast due to the limitations imposed by the maximum instantaneous charge and a demanding project schedule. Site-specific test blast programs were planned and executed in order to obtain in-situ vibration data to establish the local attenuation law, and also to better understand the role of dominant frequencies before production blasting started. This paper summarizes the main findings and solutions applied during the marine blasting project in the Sudeste Port Project.

Jan 1, 2018

By Larry Mirabelli, Gerard J. O'Brien

"The construction of the Third Harbor Tunnel is a key element of the Central Artery TunnelProject. The tunnel is to traverse Boston Harbor directly linking South Boston to EastBoston. The tunnel is a cut and cover tunnel as opposed to a bored tunnel. The cutdimensions are 95' wide, 110' deep and approximately 4000' in overall length."

Jan 1, 1993

By Virgil J. Stachura, Calvin L. Cumerlato

The Bureau of Mines conducted a series of tests to develop a blasting method that would reduce overbreak and rockfall hazards at a limestone quarry in northeastern Wisconsin. Reductions in overbreak were achieved by shortening the main explosive column and reducing the explosive load in shortened stemming zones in shotholes which were to form the highwalls. Two blasthole diameters, 3 and 4 inches, were used with 7 by 7 foot and 9 by 12 foot burdens and spacings respectively. ANFO, Comsol 300, or PowerAN were used in the body of the shots and Gelmax or 40 pct extra dynamite cartridges were used in the reduced load zones. Smoother highwalls were visually apparent, however further analysis by seismic refraction techniques were performed as an aid to studying overbreak within the rock mass.

Jan 1, 1989

By Francis O. Otuonye

The results of an ongoing study to determine the response of full contact rock bolts to shock waves due to blasting are presented. A time domain systems modeling and analysis technique was used to identify the axial and bending response of the bolt when explosives charges are detonated at close-in distances.

Jan 1, 1993

By Michael Beattie

A large open-cast limestone mine had its blasting operations severely restricted by the imposition of limiting PPV levels to protect a water pipe-line passing through the mine property. Attempts were made to measure the strains induced in the pipe by ground vibrations, so that a less restrictive blasting limitation could be established on a scientific basis.

Jan 1, 1992

By Alastair Torrance, Mitchell Nipperess, Andrew Olsson, Italo Onederra, Gary Cavanough

Components of bulk explosive products include ammonium nitrate, water, fuel, stabilizers, and calcium nitrate. The physical attributes include prill/emulsion ratio, density, and viscosity and in the case of prilled ammonium nitrate, hardness, size distribution and fuel oil absorption. These components and attributes in conjunction with ground conditions determine all aspects of explosive performance including the risk of fume. This paper presents a fume risk assessment matrix of explosives components and physical attributes as a function of a simple description of ground conditions. Instrumentation to provide a measure of the quality of the explosive product are also described and these include both “on bench” physical measurements and laboratory analysis. “On bench” methods include “in hole “density, velocity of detonation (VOD), detonation pressure and detonation temperature. Part of the quality control process involves a mobile laboratory unit which at this stage can provide measurements of water content, ammonium nitrate content, calcium nitrate content, fuel content, prill characteristics and prill/emulsion ratio. This unit can be taken to sites to enable the testing of bulk and sensitized products at site rather than after transportation.

Jan 1, 2015

By Chick Kerkering, Stephen Iverson

Perimeter control blasting is common in civil construction projects but not as common in mining. A poorly designed and executed underground mine development blast design can result in unwanted wall rock damage. This damage increases the risk of rock falls and injury. With the availability of good drilling equipment, it is a simple matter to add the few extra holes needed to change conventional drifting into drifting with perimeter control.

Jan 1, 2008

By Winfried Rosenstock, Hans-Jochen Blatte

"The guidelines of fire-fighting strategies have to be rewritten, latest since theYellowstone-Fire.CF- and S3- procedure are developed to achieve firelines of 500 ms/ h length and 100 mswidth per unit. Thereby two stretched charges burried in different depth and fired delayedin one round covering 50,000 ms2/ h with non-combustible, natural material (soil) at oncein seconds."

Jan 1, 1993

By Roger Holmberg, William Hustrulid

Swedish cautious blasting techniques were used to excavate a room at the CSM Experimental Mine in Idaho Springs, Colorado,as part of a ONWI/DOE sponsored nuclear waste disposal research program.

Jan 1, 1981

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate(AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool. The test also provided valuable data about the effects and consequences following an AN detonation. The test took place at the Utah Dugway Proving Grounds on April 27, 2018 and the debris collection was conducted the following two weeks with an average of 20 persons per day and an approximate total of 1,400 manhours. A paper was presented at the 2019 ISEE Conference on the collection efforts, challenges, and lessons learned. A complete data analysis effort was completed on the test data in 2019 that resulted in updates to the QRA Railcar Potential Explosion Site (PES)model and AN engine. The analysis included an assessment of the debris data resulting from the Derailed test. This paper is meant to serve as a summary of the analysis effort and findings and as an update to the previously presented lessons learned from the debris collection and analysis effort.

By Carlos Pañura, Michael Geldres, Alejandro Rojas

In this current era of production in large volumes of surface mining, which demands the realization of large-scale blasting, the mining industry must deal with the impact of the vibrations generated by the detonations that are carried out daily in the mines. In this context, the need arises to minimize and control the impact produced by vibrations by determining the interference times of each generated vibration waveform. The vibration waves are produced by the detonation of the explosive charges of each blasthole, analyzing the vibration waves produced by each blasthole, allow us to determine the optimal time between the detonation of each blasthole to reduce the vibrations of the production shot. Once the optimal time is found, it is possible also, to predict the vibration of the production shot (considering times and sequences) using predictive models. The waveform recorded includes information regarding the particle velocity and the dominant frequencies of the vibration. To determine the time between holes, a graph was constructed with the values of the vector Sum VPP (m / s) vs Time between blastholes (s), once the time between blastholes “t” was found, the simulation of the output sequences continued in such a way that, by adding the single waves generated by the blasthole, it gave us a record of vibrations with the lowest level of vibrations.

By Gerard O'Brien, Douglas Comstock

"The construction of the Third Harbor Tunnel is the first major portion of the Central ArteryProject. The tunnel is designed to connect South Boston to East Boston to alleviateautomobile congestion through the downtown area. The 4000' long tunnel traversesBoston harbor as a cut and cover tunnel as opposed to a bored tunnel."

Jan 1, 1993

By Robert Hopler

Accidents associated with the storage of explosives prompted regulating the locations of such storage at least as early as 1719, when an act was passed in Great Britain. During the following years various refinements to the regulations were made, but a major explosion in 1864 in which there was destruction and loss of life as far away as 10 miles, led to the landmark Explosives Act of 1875. This act certainly had influence on regulators in the United States: when Massachusetts established an explosives distance/weight table in 1904 they referred to the prior British work. Later, Colonel Dunn of The American Railway Association convened a conference of explosives manufacturers to discuss safe storage. From this conference the American Table of Distances was established in December, 1910.

Jan 1, 2007

By John M. Bolger, Keith E. McMaster

Excessive salt fines are undesirable in underground salt mining as they are considered a costly waste by-product. 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 Claude R. Ayoub, Charles A. Kliche, David G. McDowall

Homestake Mining Company's Open Cut Mine is located in Lead, South Dakota, in the northern Black Hills. The mine is within 300 feet of occupied residences on the south end, and within 1200 feet on the north end. Mining began at the north end of the open pit in October, 1983, and blasting related complaints began almost immediately. Noise and ground movement comprised the majority of the structural damage claims. As a result of these complaints, Homestake purchased a recording seismograph and began monitoring nearly every blast. In addition, the company hired a consultant to review Homestake's blasting and monitoring practices. He was also asked to do a single, one-time study of the cracks in six homes. This initial work led to Homestake monitoring all blasts with three seismographs and having South Dakota School of Mines and Technology do a year-long study of crack development and propagation in five homes in Lead.

Jan 1, 1989

By Charles Zdazinsky

"The Multiple Seed Waveform (MSW) blast vibration model, a type of waveform superpositionmodeling developed by Orica Inc., uses vibration data that is collected from a signature hole blast tocharacterize the ground’s seismic properties and determines the ground resonant frequency andfrequency range that is well supported by the ground. Additionally, the MSW model uses thisvibration data as input parameters to predict the resultant dominant frequency of a production blast. This information may in turn be used in conjunction with precise timing control to target theoptimum dominant frequency which promotes ground control."

Jan 1, 2016

By Ian A. Niell, Alastair C. Torrance

A joint research programme conducted by BHP Central Research Laboratories and Du Pont Wesfarmers Pty Ltd examined the effect of the size of cast primers on the run up and steady state detonation velocities of ammonium nitrate based explosives as a function of blasthole diameter. Both continuous and point to point velocity of detonation measurement techniques were used. The field trials examined a number of the Du Pont HDP series of primers in conjunction with ANFO, emulsion and watergel explosives. Results indicate that the run up velocity of 187mm diameter ANFO charges is negligible using cast primers as small as 1509. However, emulsion and watergel explosives did exhibit run up in both 187 and 311mm diameter blastholes, independent of the size of primer. This could last from 7 to 10 blasthole diameters.

Jan 1, 1990