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By Tom Watts

The practice of pumping bulk blasting agents is regulated by many agencies around the world. The explosives manufacturers have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping of water based blasting agents. The challenge of a Bulk Trucks or Mobile Manufacturing Units (MMUs) manufacturer is to take the objectives of the regulatory agencies and the explosives manufacturers and responsibly design and build MMUs that are safe, compliant, and cost effective without compromising serviceability.

Jan 1, 2011

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson

"The United States (U.S.) Department of Homeland Security (DHS) Directorate of Science and Technology (S&T), utilizes a probabilistic risk assessment (PRA) approach to explore the risks (anduncertainty) from chemical, biological, radiological and nuclear (CBRN) threat agents to the Homeland.This end-to-end risk methodology considers a broad range of hazards incorporating emergingtechnologies, available countermeasures and input from the Intelligence and Law Enforcementcommunities (IC/LE) to evaluate the acute risk to human health due to an attack on the U.S. homeland. The PRA generated output provides a mechanism to examine risk mitigation strategies, critical vulnerabilities, critical data and knowledge gaps and relative risk rankings of materials, targets, classes of compounds and scenarios."

Jan 1, 2017

By Qi Jinduo, Gong Min

On the basis of actual parameter of wall control blast in Nanfeng mine, China, the process of dynamic stress changing between two column charges was studied recently for a presplit-cushion blast by holographic photoelasticity. In the experimental model, two holes were simultaneously detonated from both ends (four ignition points). The bottom of the holes were loaded more than other parts (heavy charge). Under these conditions, four consecutive isochromatic fringe patterns at different times were acquired in one loading run, and the characteristics of the stress distributions were compared at different places and times in the holes. It was found that interaction types of stress waves vary along the holes. The theory is posed that the stress wave which is formed by the interaction of earlier producing P wave and later S wave along a distributed line charge is the most important part in all stress waves. Research indicates that a heavy charge in the bottom of the holes is crucial to producing a presplit-cushion effect at the bottom. "End Effect" doesn't affect the magnitude of stress along linking lines between the bottoms. The chief fields of the "End Effect" are also explained in the paper.

Jan 1, 1998

By Tom McDonald, Rodney Burke

As mining progresses in the West, the depth of material has increased, making highwall stability a major factor in safety and production. The Jim Bridger Coal Mine has made highwall stability a priority, concentrating on safety as well as increasing and improving production. Overburden depths are increasing dramatically; the geological environment consists of medium to soft material, faulting, water, and current pit alignment not favorable to joint planes. Angle drilling the presplit at 20 degrees became necessary as vertical presplit drilling produced wall failures.

Jan 1, 1997

By Cristian Rodriquez, Fernando Fernandez, Rodrigo Fuentealba, Tom BoBo, Maria Rocha, John Kemeny

This paper describes a case study that was conducted at a new mine in South America. This mine has significant geologic variations that will result in different distributions of hard and soft ore being mined at different periods of time over the mine life. A study was conducted to determine the optimum blast design that will meet the mill throughput requirement of 95,000 tonnes (104,720 tons) per day for the first 10 years of the mine life. As part of this study, field rock mass characterization and laboratory tests were conducted. This includes standard rock mechanics tests as well as rock breakage tests used in mill simulations. The geology of the ore body was broken up into four Geologic Units, and statistical variations in the properties were determined for each unit. Using this data along with the data on the occurrence of the different geologic units over time, simulations were made of the run-of-mine (ROM) fragmentation due to different blast designs, and these results were used in simulating the resulting throughput after crushing and grinding. Four blast designs were considered with powder factors of 0.44, 0.54, 0.64 and 0.94 kg/t. The results of this study show that determining the proper blast design is important in ensuring that the mill throughput requirement will be met over the mine life.

Jan 1, 2015

By R H. Stevenson

This paper deals with a new variation of the cast blasting technique, where-in the object is to cast the economic deposit out front under the overburden, while avoiding dilution from the floor material. To date, the technique has been successfully applied at two cement quarries in Iowa and at a granite quarry in Minnesota.

Jan 1, 1991

By M Sampara, W Comeau

The introduction of large-diameter holes to underground mining has made possible the development of new mining methods such as the Vertical Crater Retreat (V.C.R.) method. It is not only the safest underground excavation system but also provides mass production at a lower cost than any conventional mining method (1, 2, 3, 4, 5).

Jan 1, 1981

By Aiden Carey, Jim Kennedy

During December 2007, Lake Cowal Gold Mine located in New South Wales, Australia experienced a significant pit wall failure. The wall failure resulted in the deposition of a large quantity of saprolite consisting largely of clays and lake bed sediments to the bottom of the Phase 1 open pit mine. This wall failure ultimately buried two loaded blast patterns.

Jan 1, 2011

By C. K. McKenzie

Presents outline of flyrock model and a field procedure to validate predictions of maximum projection distance. Field results are presented from 13 field tests with two different hole diameters.

Feb 1, 2020

By Tacio Ferreira

A surface copper mine in the Western United States faced challenges in recovering rock and ore from final walls because of geotechnical constraints that require restrictions on methods for loading blastholes adjacent to the pit boundaries to preserve wall conditions. The operation had been using the same drill and blast designs for years. With changing geology, such as harder rock, as mining progressed, material was being left unmined in final walls because of poor breakage. The amount of unrecovered, unprocessed ore was estimated at approximately 380,000 tons a year generated from an average of 60 final wall blasts performed annually. The mine engineering team and Dyno Nobel engaged to minimize the amount of material left on the final pit walls. In this paper we present how we collected data, reviewed design standards, and found opportunities to improve ore recovery from pit final walls without increasing drilling and blasting costs. The results collected from implementing the new design on two benches showed the potential for extra revenue of approximately $3.6 million generated annually from reducing final wall unrecoverable underbreak by nearly 71% on the mine’s highwalls.

Jan 21, 2025

By Armin Iravani, Changping Yi, Matthias Wimmer, Daniel Johansson, Santiago Gómez, Håkan Schunnesson

Sublevel caving (SLC) is a mass mining method based upon the utilization of gravity flow of blasted ore and caved waste rock. Drilling and blasting are the initial and the major impact on primary fragmentation and later material flow characteristics. The heterogeneity of rock mass has a great impact on materials’ mechanical properties and plays a significant role in rock fragmentation by blasting. In this work, a numerical model for sublevel caving based on 3D Voronoi tessellations was developed to section rock mass into arbitrarily shaped regions for modelling the heterogeneous rock mass. A coupled finite element and discrete element method was employed to investigate both the fragmentation due to blasting and the gravity flow of ore in a heterogeneous orebody. In the coupled model, the caved waste rock was modelled with loose discrete particles while the orebody to be blasted was simulated with bonded particles. The detonation of explosives was described with a particle blast method and a finite element model was used to model the remaining orebody. The results indicated that the fragmentation at the upper part of the ring is coarse while it is fine at the lower part of the ring. The heterogeneity of rock mass induced some boulders after blasting.

Feb 6, 2023

By Braden Lusk

Vibrations as a result of blasting practices in mining engineering are a complex phenomenon controlled by many variables. Mine blast vibration modeling and prediction is becoming more important as a consequence of the general negative perception of mining activity by the public. Many communities (all over the world) close to mining activity often complain about airblast and vibrations produced from blasting activity. It is important for the mining industry to have tools and understandable methodologies to model and predict blast vibration. These tools can then be used to control vibration at neighboring structures.

Jan 1, 2013

By Jim Daley

This case history discusses a pre-split test conducted at BHP Mineralss Navajo Mine in Fruitland, New Mexico. The test was an extension of earlier pre-split testing conducted by Virgil Stachura of the U.S. Bureau of Mines in conjunction with Navajo Mine and WESCO Inc. which tested low-density product in 10.625 diameter holes.

Jan 1, 1996

By Wawa Jaka Sungkawa, Slamet Rachman Jaka, Tom Dermody

A project was undertaken to research and develop a method to confidently predict vibration. It was decided that the scaled distance formulas were not adequate to predict vibration when using non-electric detonators, as accurate wave propagation could not be achieved. The problem is how to manage of complex geology condition related with wave propagation in ground vibration control. Geological condition mapping with specific spatial range can and combine with Signature Hole Analysis be a solution to make wave propagation easier to accommodate in ground vibration control

Feb 1, 2020

By John Vynne, John Hutchings

There have been a number of recent technological advances in instrumentation for blasthole drills, and more specifically in drill monitoring and HPGPS guidance systems. Likewise, great strides have been made in the development of drill and blast software systems which are user friendly, while providing far greater capability to accurately design and monitor drill and blast patterns.

Jan 1, 2011

By Robert Jacob Cefalo, Rio Tinto Kennecott

At the end of 2016, the Mine started a new ore phase in the section of the pit located on the East Wall. The East Wall geological structures required controlled blasting for peak particle velocity (PPV) frequency vibrations to protect the wall. Frequency controlled blasting using linear seed wave superposition modeling was required and implemented to reduce the far-field affects to the wall. This paper covers the work done by the drill and blast engineering group, controls used to protect the mine infrastructure, and the continuation of work-to-date of frequency controlled blasting for wall stability. The narrow width of the layback required the combination of hole sizes to blast large diameter production patterns with smaller diameter trim patterns in the same blast. A single blast had to use different burden & spacing and hole diameters and required the use of different timings throughout the pattern. Electronic detonators were required to limit blast vibrations and accommodate the specific timings needed to reduce low frequencies. The geotechnical group with the help of geotechnical radars worked with the drill and blast group on creating a tracking and reporting of blast performance. The radar readings informed the drill and blast engineers of the performance of the blast as it related to the long term performance of the highwall

Jan 1, 2019

By James R. Houston, Wendel Clay Chaffin, John Loviza

During the spring and summer of 1993 the largest pipeline in Tennessee was installed as part of the upgrading of Nashville's sewage needs through the year 2035. This new 3.3 million dollar outfall project is able to carry 330 million gallons of treated sewage water daily. Special projects required special equipment as this project was safely and quickly installed.

Jan 1, 1995

By Sean Cahill

The Blasting In the summer of 1999, a Southern California drilling and blasting company conducted blasting as part of the grading operations at the Highlands Ranch development in San Diego, California. Highlands Ranch was a new single family residential project located near older residential properties in the area. Blasting was necessary to remove indigenous meta-volcanic rock associated with the local geology.

Jan 1, 2003

By Joshua Hoffman, Braden Lusk, Perry Kyle

With the advent of any new technology comes the necessity of fully understanding the mechanics of that technology. The Shock Tunnel is one such technology that provides a cost effective means of simulating large-scale explosions while requiring a fraction of the explosive and space. Although the technique is known and practiced, the dynamics and mechanics of this technology has yet to be fully understood. A relationship between the energy potential of a given explosive and the energy realized at a set of distances was determined. This data was then compared to the energies realized from the same explosive when utilized in conjunction with a shock tunnel. A relationship between potential and realized energy outputs from explosive based shock tunnels exists and the understanding of this relationship would allow all for predictions to be made to forecast a specific amount of explosive required to produce a desired energy output. This energy output should then be relatable to peak pressures produced via the shock tunnel. Two shock tunnels are currently accessible for this study, the first under the direction of the University of Kentucky, and a second under the direction of the Missouri University of Science and Technology. The two shock tunnels differ in dimensions but share common construction materials. Energy realized from a shock tunnel is hypothesized to be a function of the shock tunnel’s dimensions. This study explores how different geometries affect the shock tunnel’s performance; this exploration is broken down into three phases. Phase 1: Open arena testing in which theoretical energies produced by the detonation of small (<1.0 kg) charges are compared to actual experimental values. Phase 2: Shock Tunnel testing in which realized energies are experimentally recorded for the UK shock tunnel. Phase 3: Analysis of the data to lay down the ground work for producing a pressure-forecasting tool given shock tunnel dimensions and explosive characteristics with the possible detection of avenues for optimization of shock tunnels.

Jan 1, 2009

By Henry P. Van Ormer

This paper is written to outline the capabilities and flexibility of the electric motor driven oil cooled rotary screw air compressor in construction and mining applications. With the changing economics between fuel and electric power all over the world, the viability of the electric motor is a choice all construction and mining people should be aware of. The advent of large efficient electric motor driven rotary screw compressors have given a great deal of flexibility to the use of these units on many applications not considered before. Examples are given for rotary and percussion drilling, fennels, and underground, sandblasting and "uniting, general uses - shows wheel mounted and skid mounted units.

Jan 1, 1976