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By Terri Jordan, Kenneth Hollingshead, Mary Jo Barkaszi

The Port of Miami, Miami-Dade County, Florida (Port) is the largest container port in the State of Florida. However, it is located in the center of a diverse ecosystem. Biscayne Bay surrounds the Port and portions of the bay have been designated as a National Park, a Florida Aquatic Preserve and a state Critical Wildlife Area. The bay is home to many protected, threatened and endangered species including the Florida manatee, five sea turtle species, American crocodile and bottlenose dolphin, in addition to important recreational and commercial fish species.

Jan 1, 2007

By Neal Lee, Braden Lusk, John Silva Castro

One of the most common assumptions regarding the use of ANFO versus utilizing 100% sensitized emulsion is that ANFO “turns over” the muck-pile better, due to the “higher gas volume” supposedly inherent in ANFO. This paper examines this assumption and provides quantitative data for analysis. Total gas volume from each product was evaluated using Orica’s I.D.E.X. Code analysis. This analysis was used to determine if gas volume is a significant contributor to differences in fragmentation and movement between blasts utilizing the two different products. A constant drilling and blasting cost per yard for given cut depth, hole diameter, stemming height and rock type was utilized. The cost per yard was held constant by adjusting patterns considering product, accessory, and drilling costs. Photographic fragmentation analysis, dig rates measured quantitatively through production tracking and time studies and qualitative information about the diggability of the blast provided through video recordings were used to evaluate performance. The data collected during the study is presented and recommendations are made regarding the performance of ANFO and Emulsion holding other variables constant for a limited number of blasts.

Jan 1, 2012

By Jhon J. Silva Castro

Blast vibration records used in mining contain unwanted information in the form of noise due to long-period drifts, background noise, and noise due to the conversion of the analogue signal to a digital signal. When recorded signals from blasting are used to find other physical variables, such as going from particle velocity to acceleration or displacement, the additional information in the vibration signal can result in inaccuracies in the estimation of the peak values and more dramatically, the results in displacement or acceleration can be nonzero near the end of the record. There are different proposed methods to clean or filter the unwanted information from the signal. All of the methods are based on finding the best fit of the record average value (baseline) and then subtracting from the record under analysis to produce the desirable adjustment. Different criteria and functions are used to define the best fit. The function to use will depend on the shape of the record average values. The main characteristic of the baseline function is that it represents a low frequency wave. Such a low frequency wave can be a periodic function or a polynomial expression of nth order. According to the order of the polynomial expression, the baseline correction can be linear, parabolic or high order. In this document the detailed procedure and the results for the baseline correction of a blast vibration record using a periodic function and a polynomial expression of different order is presented. The results show that the drift problem when displacement is calculate using velocity records increases with the increase of the distance from the blast.

Jan 1, 2015

By S. Behera, K. Dey

This paper presents a methodology for finite element (FE) modelling to analyse the total deformation of rockmass under blast-load, with a focus on predicting backbreak that may occur during surface blasting operations. Backbreak can result from improper use of explosive energy, leading to damage beyond the excavation zone and jeopardizing operational safety and productivity. The paper highlights the impacts of backbreak on bench stability, excavator operation, drilling operation, flyrock generation, and improper fragmentation and boulder formation in surface blasting. However, prior estimation of extent of rock breakage zone can provide an idea to formulate the blast design to control the backbreak. While vibration-based prediction models are commonly used to estimate backbreak, they require physical blasting experimentation. To overcome this limitation, the paper describes the development of a FE model using ANSYS Explicit dynamics, which simulates rock blasting and calculates the total deformation of the rockmass. The rockmass deformation is modelled using Drucker-Prager (D-P) strength model with the Jones-Wilkins-Lee (JWL) equation of state for the explosives. The accuracy of the FE model is evaluated through physical experiments, and the results are compared with the vibration models. The FE model demonstrates close proximity to physical observations as well as vibration model result in predicting backbreak, thereby offering a promising alternative to vibration-based prediction models. The primary objective of the study is to predict the response of the insitu rockmass to explosive blast loading and determine the effective rock breakage zone.

Jan 1, 2024

By Paul Worsey, Braden Lusk, Seokbin Lim

This paper discusses the theory and experiment involved in the discovery of the mechanisms of Linear Shaped Charges, which are much different from those for Conical Shaped Charges. Linear Shaped Charges (LSC) have been assumed to function in the same manner as Conical Shaped Charges (CSC) in the published literature on the subject. Much work has been done on CSC for military purposes, but there is limited information about the mechanics of LSC. Previous theories have cited the formation of a Monroe Jet as the dominant process. The Monroe Effect describes what happens to a target below the charge following detonation of the charge, and prescribes a fluid jet process for penetration. The fluid jet comprised of the liner material is the cutting device in CSC and has been extensively studied. Recent work at the University of Missouri at Rolla (UMR) cutting concrete with LSC has surprisingly shown that there is not a fluid jet process in LSC. After completing several reinforced concrete penetration tests, minimally deformed copper blades were found in the debris. Initially, the blades were suspected to be misfires or malfunctioned charge remnants. However, results were good and blades were found after every single test. Upon closer inspection, the ribbons were found to be folded copper and they were suspected to be the bottom liner of the LSC. A test series was conducted to verify the new theory by experiment.

Jan 1, 2005

By Lon Santis, David Buckwalter, Ken Steinmetz

This paper describes a magazine security system using two readily available cellular telephone-based technologies. The system is comprised of vibration sensors and remote cameras. The system is used at a Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) licensed explosives storage location in Pennsylvania to comply with PA Department of Environmental Protection (PADEP) regulations. The system provides instant notification to the licensee via cellular modems, text messaging, phone call, and e-mail. Likewise, the licensee can control the system remotely over the internet and using text messaging commands. The vibration sensors attach to the door of the metal type I magazines magnetically and detect any movement or vibration. The cameras trigger on movement and thermal radiation changes and can also be triggered manually to check alarms received from the vibration sensors. The previous system was comprised of a base unit and magnetic strips. The magnetic strips were powered by a hard line from the control unit and mounted on the doors and top of magazine creating a bond, that when broken triggered an alarm. Our main issues with the unit were the delay in alert times and tech support. Because of these issues, we decided an upgrade was necessary. Compared to that previous system used at this site, these new systems are highly affordable, carefree and reliable.

Jan 1, 2014

By Frank Hirthammer

Over the past few years, development and implementation of digital logistics solutions has convinced users of many additional advantages of this technology. Barcode labeling and reading increases the company’s efficiency and safety by reducing handwritten documentation and preventing misinformation. Sustainable information and productivity management is a significant advantage in competition. Since manufacturing information is tracked throughout the whole supply chain until the final consumer, all processes become transparent what ensures efficient risk tracking, correct disclosure to authorities (if required), and the compliance with company rules.

Jan 1, 2018

By Richard Turnbull

Maules Creek mine is an open cut coal near Boggabri in the Gunnedah Basin of New South Wales, Australia. The mine is currently operating at an annualised run rate of 9.5Mt of saleable coal. The plan is to ramp up production to 13Mtpa. Maules Creek has multiple seams each with varying depths; the inter-burden ranges from a few metres thick to greater than 30m (98ft). Due to this, Maules Creek mine is utilising truck shovel operations rather than a cast/dozer push operation.

Jan 1, 2018

By Francisco Sena Leite, Vinicius Miranda

Mine blasting is directly associated with ground vibration. If these affect critical structures (buildings pit walls, etc.) they must be mitigated to reduce the environment and social impacts. Vibration monitoring and control is one of the most important procedures in blasting because it will impact short and long term incidents associated with this blast effect. Technology moves ever forward, and today we have personal devices that are equipped with an array of sensors, for that reason the authors decided to investigate the possibility of using a personal device to do vibration control. This case study compares the same blast measured with a traditional seismograph and a smartphone. To validate this new methodology, attenuation laws were built with data from a traditional seismograph and a smartphone application. Predictions were also made prior to a set of blasts. Residual analysis was used for data validation from the two different sources. From the performed analysis, to prove the validity of this new methodology, the normality tests for statistics residues analysis proves that it is possible to infer that the model has a null residual mean and a small residual error. The achieved results show the accuracy of these devices, the authors pretend to show the potential of this equipment and open a completely new door for vibration analysis.

Jan 1, 2018

By Daodu Opeyemi

This paper describes several damages of blasting operations on some case studies, analyzes causative factors, and emphasizes preventive measures. Due to several complaints from some host mining communities as a result of blasting operations; two quarries from Nigeria suburbs were visited for study. The blasting design parameters in the mining companies were examined. Also, the history and existing conclusion of the neighboring buildings were studied using structured questionnaire, personal contact and visual examination. From the study carried out, it was discovered that varying negative environmental and socio economic problems resulted from the effects of vibration and flyrock on the nearby agro mining communities. The consequences are not limited to distortion of landscape but also include extinction of some animals, poor agricultural productivity; such as damages to economic trees and reduction in the yield of crops, health problems as a result of shock resulting to psychological disturbances, communal conflicts, blast induced cracks of structures and sometimes total collapse of host agro mining buildings, thus indicating that most mines did not comply with the safety concept of the existing environmental laws and regulations. Based on the results of the study it was recommended that proper blast design of quarries/mines should be conducted and the compulsory use of seismograph will be crucial in developing predictions. Environmental impact assessment should always be conducted before, during and after each blasting operation. Other possible control of vibration, flyrock and airblast, are also discussed in the paper

Jan 1, 2009

By Robert Hopler

INTRODUCTION NOT so very many years ago the farm was about the last place where one would expect to find up-to-date mechanical appliances. Steam, explosives, electricity—the factors which have made the world in general, and America in particular, what it is today— were indispensable for the railroad and the steamboat, the factory and the mine, but the farmer’s work was generally run on a comparatively small scale, and was mostly done by the muscles of men or draft animals. Today, however, the farmer as well as the manufacturer, the contractor and the miner, fully appreciate the value of labor-saving devices. Every up-to date farm, large or small, has modem machinery that tends to reduce the cost of production or to improve farm products.

Jan 1, 2011

By Hans-Peter Rossmanith

Fracture mechanics (Atkinson 1987, Broek 1988, Rossmanith 1978-2002, 1983, 1997, Kanninen & Popelar 1985) and wave propagation (Graf 1975, Rinehart 1975) form the main ingredients in the new electronic detonator based blasting technology. The full potential of using short delay initiation timing in bench and underground blasting can only be exploited if the underlying physical processes are properly understood. From a structural geology point of view, in many open pit mine operations, blasting is performed in incompetent and/or loose rock. Under such conditions the stress waves produced by blasting very quickly dissipate in the rock mass and often their energy cannot effectively be put to work. This contribution shows the effect of open and closed joints – and to some degree also faulting – on the blast wave field and shows the influence of structural geology on the blasting result. A simple engineering method which combines wave propagation and impact mechanics is developed in order to assist the non-scientifically trained blaster in understanding blasting in blocky rock formations. Extensive use will be made of the so-called Lagrange diagram which was introduced in detail in the author’s previous lecture at ISEE 2003 (Rossmanith 2003). This presentation can be considered a continuation of the 2003 presentation.

Jan 1, 2004

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 Guo Ziqing, Tang Qiuming, Liu Yuanyuan

The channel-type non-mechanical stirring production process is a new developed technology for emulsion explosives in recent years. It removes traditional equipment such as mechanical-mixing emulsification, mechanical-mixing sensitization, matrix pumping, and explosive pumping, and has been applied in China. This technique achieves a fusion of higher intrinsic safety and lower cost, as well as the excellent quality of products and high efficiency of production. The emulsion particle diameter is about 0.5μm. The storage period of emulsion explosive produced with span-80 emulsifier is more than 7 months.

Jan 21, 2025

By Wayne Rogers, Sarma Kanchibotla, Alan Tordoir, Bryon Bisiauz, Seth Ako, Eric Engmann

Blast induced rock mass displacement can have a significant impact on ore loss & dilution. The mischaracterization of the grade boundaries both prior to, as well as a result of blasting can lead to significant financial losses on account of ore loss and dilution. Ore dilution occurs when waste material is miscategorised as ore and sent for processing diluting the run of mine head grade and recovery. Ore loss takes place when valuable mineral is miscategorised as waste and sent to the waste dumps, thus never being processed and recovered.

Jan 1, 2012

By Ronald Ticona

Generally, the drilling and blasting operation are managed independently to the processing plant outcomes. Therefore, the technical segmentation to determinate the ore drill and blast designs do not include processing plant rock properties such as Bond Work Index, Axb, Drop Weight Index or other. This work describes the case study of a copper mine in Peru, which, together with its strategic partner ORICA, have implemented projects focused on optimizing mine fragmentation. The year 2021, mine operation according to its mine plan would have a significantly increased SAG mill hardness, which would impact directly on copper concentrated production. An integrated strategy from mine to plant has become necessary to maintain the production levels.

Feb 6, 2023

By Finn Ouchterlony

"Recently detailed fragmentation data from blasts fired with electronic delay detonators (EDDs) in the Red Dog mine in Alaska were presented. They include a comparison with pyrotechnic detonators fordifferent in-­-row delays in a standard pattern and EDDs in an expanded pattern. Fragmentation was measured on the belt after the primary crusher. The Rosin-­-Rammler function (RR, two parameters) was used to describe the crusher product. This was combined with the JK SimMet crusher model and the CZM blast model (Crushed Zone Model, three to five parameters) to estimate a reasonable crusher feed (muck pile fragmentation or run of mine, ROM) for each fitted product. In this way the effect of delay timing and electronic detonators on the median fragment size x50 and uniformity coefficient n for both crusher product and the blasted rock was determined. "

Jan 1, 2012

By David Nemir, Jan Beck

A challenge in materials science is the production of a bulk solid material from a powder precursor. One solution is to use shockwave consolidation whereby a ductile tube is loaded with the powder of interest and then surrounded by an explosive. A detonator at the top of the explosive column initiates a symmetrical high-pressure pulse that moves inward and down the tube, causing the tube to deform and the interior powders to consolidate into a dense, well bonded bulk material.

Jan 1, 2016

By Jennifer Paukula, Steven Lindsay, S. Joon Kim

String loading is the placement of a bead or ‘string’ of emulsion along the lower edge of a development drill hole. The loading hose extraction rate controls the amount of emulsion placed in each drill hole. This allows a controlled distribution of explosive energy throughout the development round. Center holes are loaded using the slowest extraction rate causing the majority of the explosive energy to be placed in the center of the round. The loading hose is extracted successively faster for the buffer and perimeter holes causing less explosive energy to be placed near the edge of the blast. This causes less damage to the rock mass that remains in place after the development blast.

Jan 1, 2012

By D. Mason, W. J. Birch

Blasting operations are arguably one of the most contentious areas of surface mining.Many operators carry out outine monitoring as required by Mineral Planning Authorities. However in so doing they only concentrate on the observed Maximum Peak Particle Velocity (PPV) being below the statutory limit and pay little or no attention to the measurable parameters that determine this value (e.g. scaled distance, burden, detonator type, blast type or rock type). Such practice is “monitoring to comply”. What is needed is for the operators to adopt a methodology that clearly demonstrates to the appropriate regulators that the operator is “planning to comply”. The aim of the exercise being to deliver a process that is seen to be transparent, accountable, and quantifiable, which seeks to minimise environmental impact whilst not compromising the efficiency of the blasting operations mine.

Jan 1, 2011