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By H. R. Maggard, C. M. Bollinger

Solving the problem of detecting underwater explosions from "dynamite fishing" can be done by using a system of sonobuoys programmed to detect the acoustic waves from underwater explosions. The system includes three anchored sonobuoys, which have radio communication to a central station. Each sonobuoy will detect the direction the blast occurred, and then send the magnitude of the acoustic waves and the blast direction to the central station where the blast distance will be calculated. The central station can the send the coordinates to the authorities who can find the location using GPS systems onboard their boats.

Jan 1, 2004

By R. F. Favreau, Patrice Favreau

In many quarries and construction sites visited by the authors over the last 50 years, the latter have observed muck piles from blasting with explosives, which included numerous large blocks, in some cases of dimensions larger than the input to the crusher. The names of these sites cannot be given in the article because the owners insist that data obtained on such visits be kept confidential. Often the blasters felt that the natural fissures in the rock would compensate for the use of a low powder factor, and they asked the authors to explain why such blocks were present. A detailed analysis of the situation often indicated that the cause of the blocks is that explained by figures such as 6 and 7 below in the article.

Jan 1, 2018

By Auã Kiahla, Tomi Kouvonen, Vinicius Miranda

Through numerical mathematical processing (Taylor’s approach and numerical derivation) the original data supplied by the accelerometer’s sensors was transformed into velocity and, after the data mining, a statistics residue analysis was applied in order to evaluate if the data from the prototype and from the traditional seismographs were similar. The data from each system was used to estimate the attenuation law and the results are shown in this paper

Feb 1, 2020

By Gavin Yuill, Kameron Ray

"The impact on vibration model accuracy by input data that is inaccurate was previously unknown, butthought to introduce significant error. This paper explores the impact of accuracy of different GPSreceivers, bulk truck density fluctuations, and charge weight location convention on the accuracy of the final vibration model output. GPS accuracy is compared between a professional Differential GPS, a “prosumer” GPS unit and a standard consumer GPS chip commonly found in cell phones. Bulk truck density fluctuations are compared from the density given by the operator and the actual cup density measured in the field. Charge weight locations explored are from the bottom of the blast hole, center of the powder column, and collar of the hole. The findings show that the weakest link in vibration model creation is actually low seismograph accuracy standards. Errors introduced from such are generally greater than those introduced from other sources."

Jan 1, 2017

By Demosthenes (Dennis) Efstratiadis

After European Council’s Directive 93/15/EEC of 5 April 1993 on the harmonization of the provisions relating to the placing on the market and supervision of explosives for civil uses, the so called ”Intra-Community Transfer of Civil Explosives” has been possible between users in the member States of the European Union. In line with this new approach, the placing on the market and the supervision of explosives for civilian use are subject to essential safety requirements. The explosives market in Italy is regulated by the ”day consumption of explosives” that imposes the user to have on site just the strict quantities of explosives and accessories that are necessary for the daily drill and blast activities. Any eventually advanced explosives’ quantities should be destroyed, either returned to the provider’s magazine until the 24:00 hours of the same day.

Jan 1, 2018

By Harry Verakis

Flyrock is the second leading cause of all blasting related injuries in surface coal, metal and nonmetal mining operations. It is also a primary cause of property damage, monetary losses and “near misses.” For the period 1978 to 2008 flyrock accounted for 11.6 percent of all blasting-related injuries in surface coal, metal, and nonmetal mines. A large amount of published material has been published on the safety hazard of flyrock, on ways to predict how far rock will travel from a blast, as well as ways to protect mine personnel and neighbors from flyrock. However, flyrock incidents continue to occur resulting in fatalities and “near misses” that could have caused fatalities. It was only good fortune in some instances that no one was in the mine's parking lot or other unprotected area when flyrock rained down or in harm’s way when a large rock punched a hole in the roof of a building or other structure.

Jan 1, 2011

By X. Gumede

A model is being developed to quantify the benefits for mining houses resulting from the reduction in greenhouse gas and energy consumption by the application of innovative blast designs in addition to direct financial benefits throughout the mine to mill value chain. The conversion from shock tube initiation systems to electronics and some changes to powder factor measured on an open pit mine had previously been used to show significant improvement on blast outputs. Benefits were realised on drilling, blasting, loading, hauling and beneficiation. Quantification of the relationship between powder factor and reduced greenhouse gasses is investigated in this study. The study has highlighted new data that must be recorded and hence some assumptions were made as to fuel consumption and the energy in crushing was obtained from the Bond work equation. The mine to mill projects in an open pit platinum mine and a quarry produced energy savings and reduced greenhouse gas emissions associated with the careful application of explosives and blast innovations. The less fines project showed an increased carbon footprint. The model provides a new insight into how project feasibility should be decided based on economic and environmental viability.

Jan 1, 2012

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 Rachel Bauer, Jacob Henderson, Dr. Catherine Johnson

Capital Quarries in Owensville, Missouri faces several challenges when designing a blast that allows for ease of movement while maintaining controlled throw and compliant air over pressure. The primary challenge is the nearest non-owned structure (NNOS) is a residential home located 250 feet from the quarry. Another challenge is a production bench which is 100 feet tall and separated from the NNOS by Pennsylvanian fire clay that filters out high frequency waves from the blast. Material from the blast must also be less than 5 inches in order to be processed by the crusher in the quarry. To provide as much relief as possible, production shots will consist of a single row with the minimum required burden. To design the shot, signature hole analysis was used to determine the optimal timing between powder columns. Electronic detonators provided an accurately timed shot to minimize the amplitude of the vibrations while maximizing the frequencies. Boretraking and 3D profiling with Renishaw laser profiler and Strayos drone photogrammetry provided an accurate burden measurement. Powder factor was kept at 1.3 tons/lb using bulk emulsion. The boreholes were split into 5 powder columns with the top of the hole firing first in order to blast to floor grade. The resulting shot produced good fragmentation and shot to floor grade. Seismograph readings showed air over pressure vibrations within legal limits. Due to this success, multiple shots will be designed using the process described.

Feb 6, 2023

By Robert Pumpelly

During my nearly 30 years with ATF, (Bureau of Alcohol, Tobacco, Firearms & Explosives), I conducted hundreds of inspections. In many cases hours of time were wasted because the licensee or permittee, who had basically done everything right, was not prepared for the audit. In these cases, required documents were scattered, personnel were unprepared and no plan was in place. This paper will provide some simple steps to avoid these embarrassing delays. A list of common violations is also provided.

Jan 1, 2010

By Dale Ramsey

As someone who has enjoyed photography as a hobby for many years, aerial photography to me has always been an exciting way to give a different perspective to my images. Our industry is always in search of new technology for bet­ter and more cost effective methods to improve our trade and aerial photography is a great tool to improve project planning or document its progress. It has typically involved conventional aircraft both fixed wing and helicopters but neither method is always available or cost effective. The lat­est innovation since digital imaging is the development of Unmanned Aerial Vehicles (UAVs) or drones. But there is a lot of uncertainty with this amazing new technology’s fu­ture in the U.S. as the Federal Aviation Administration (FAA) is under review and development of UAV regulations for commercial use which are slated to be completed in 2015.

Jan 1, 2015

By Toby Forney, Joshua Schoonover

In typical surface quarry operations, productivity and efficiency related to pit development begin with drilling and blasting efforts. By embedding technology within drilling and blasting operations, blast results can be tailored to benefit the quarry by driving continuous improvement of production. This technical paper will focus on the continuous improvement efforts at a cement limestone quarry in Maryland and how those efforts have impacted mining production, safety, and efficiency with the application of specific blasting technologies.

Feb 6, 2023

By C. T. Aimone-Martin, B. M. Meins

This paper compares response of large urban structures to small charge weight, ultra-high frequency rock blast excitation from contiguous excavation to that of houses to more distant, larger charge weight blasts. Time correlated responses were measured for both structures at the corners, top and bottom of the structures as well as in the foundation rock below the bottom. The comparison allowed the following conclusions: Close-in blasting with direct rock to building wave transmission imposes short wave length excitation which fails to excite the large, massive structures synchronously whereas the more distant blasts do synchronously excite houses. The larger urban structures respond predominantly in wave transmission mode where there is a noticeable difference in time, frequency, phase and amplitude of motions measured at the bottom and top corners of the structure. Excitation motions along the base of the larger urban structures also differs in time, frequency, phase and ampli-tude. The short wave length of the excitation motions leads to attenuation of the peak particle veloc-ity along the base. Ultra-high excitation frequencies, which are much higher than the expected struc-tural natural frequencies, lead to deamplification for all events for the large urban structures.

Jan 1, 2018

By Angel Rafael Fernandez, Yahya Khader Al-Harbi, Benjamin Cebrian Romo, Antonio Morato Medina

The kingdom of Saudi Arabia has set the goal to diversify their economy from oil into different fields including mining. As the vast Arabian Peninsula is explored, orebodies of Aluminium, Copper, Gold and Phosphates are found in high grades and tonnages. Hard rock is present in most of the projects and require high quality blasting in regard to ore dilution, wall control and fragmentation. Maaden Gold has currently 4 open pit mining operations 1 new opening and 2 underground. More projects are coming online in the next few months and years. A new generation of mining engineers need to apply drilling and blasting techniques that compete with modern and efficient open pit and underground mines.

Feb 6, 2023

By S. Mansfield, A. Sharma

At a large open cut copper mine, in pit crushing and conveying is used to shorten haul routes and minimise stockpiling of ore. This strategy decreases capital expenditure by reducing the number of haul trucks and excavators required and reduces the need to rehandle ore from stockpiles with a secondary load and haul fleet, with an overall goal of lowering operating costs and carbon emissions. As the mine has developed and expanded, it was necessary to extend the conveying network and install a fourth, semi-mobile crusher to increase the output of the operation, while maintaining the operational efficiencies. This required the blasting of a new tipping bench and pocket for the installation of one of the largest and most powerful semi-mobile, crushing plants. Fed by 360 tonne (396 ton) ultra-heavy class haul trucks, the KB 63-130 Pro gyratory crusher is the highest capacity available in the market. This paper describes the holistic process that was applied to model, design and execute the blasts required to create the pocket for the semi-mobile crusher, the surrounding tipping bench, plus the conveyor corridor and access ramp used by the ultra-heavy class trucks.

Jan 1, 2024

By Cary Moffat, John Kita, Rick Walker

The Lac des Iles Mine, in an isolated area of NorthwesternOntario is a relatively new open pit platinum and palladium mine. They were encountering problems with the equipment and production scheduling when ramping down to begin production on the subsequent benches. A co-operative effort between Lac des Iles Mine operation people, ICI Explosives, and the mines drilling and blasting contractor - Consbec Inc., resulted in a decision being made to use full depth sinking cuts to provide access to the next bench.

Jan 1, 1996

By Rachel L. Bauer, Catherine E. Johnson

Explosive demolition involves first, the use of cutting charges to sever a column and second, kicker charges to move it out of alignment. Dynamite is the traditional explosive used in kicker charges as it is inexpensive, easy to initiate, and has a consistent track record of use. Dynamite, however, has health concerns in handling, fragmentation concerns from direct contact on the beam, and availability concerns due to being manufactured at only one location in the continental United States. Recently, water-cased kicker charges have been used in industry, and research has shown that a reduced dynamite mass is possible due to the added confinement, for energetic performance, and the incompressible fluid, which aids in the transfer of explosive energy into beam movement. This research will compare two different explosives, an emulsion (DYNO AP), and binary (HELIX), to dynamite for use in kicker charges, both with and without water-casing. Emulsion is commonly used in rock blasting to create a large push or throw due to its high gas volume production which could translate to kicker charge movement. HELIX is a binary explosive commonly used by the military in breaching charges with water backing. Experimental tests placed kicker charges at the base of a hanging steel column, modifying the ballistic mortar test used to determine explosive power. The study shows that water-casing effectively reduces air overpressure and enhances explosive performance. Among the tested explosives, HELIX showed the most substantial improvements with a 1.8 dB reduction in air overpressure and a 3.2 m/s (10.5 ft/s) increase in column velocity when water-cased. Dynamite and emulsion also benefited from water casing, with decreases in air overpressure (1.1 and 0.7 dB respectively) and increases in column velocity (1.1 and 0.7 m/s (3.6 and 2.3 ft/s) respectively). This research also shows that emulsion is a viable replacement for dynamite in demolition projects, performing similarly in both traditional use and water-cased charges.

Jan 21, 2025

By F. Schott, M. James, G. May, E. Baker, C. Johnson, R. Bauer

Explosive demolition typically utilizes cutting charges to sever columns, detonating cord to time charges and provide an initiation path, and dynamite as a kicker charge. The kicker charges of dynamite are used to “move” columns out of alignment, causing collapse. Demolition projects involving dynamite can pose significant health and safety risks to workers and the public. Nitroglycerin in dynamite can cause dizziness, fainting, and other health problems. Moreover, dynamite placed directly on columns can result in fragmentation and cutoffs, preventing other charges from being initiated and resulting in incomplete demolition. Fragmentation can occur from columns and travel significant distances from the initiation point, sometimes reaching hundreds of meters away. This fragmentation can pose serious dangers to anyone in the vicinity, including workers and members of the public, as the debris can cause severe injuries and property damage. The force and velocity of the fragmented material can be unpredictable and difficult to control, making it important to take proper safety precautions and consider alternative demolition methods that minimize the risk of fragmentation. Previous work concluded that casing charges in water showed that a reduced dynamite charge mass could still successfully kick the charge out of alignment. This study aims to investigate the use of Pentolite boosters in water-cased charges as a safer alternative to dynamite-based demolition. The research involved testing various amounts of dynamite and pentolite boosters in water to compare their effectiveness in moving a hanging W-beam, which swung freely like a ballistic pendulum. Water-cased charges consistently move the column at a higher velocity than the traditional dynamite charge placed directly on the column. The method of water-casing increased the area of impact and impulse felt by the column, improving demolition efficiency when compared to traditional demolition methods as found in previous studies. Pentolite water-cased charges moved the column at 7.8 meters/second (m/s) while the dynamite water charge moved the column at 5.9 m/s. The increased strength and explosive properties of the pentolite contributed to this increase in velocity. This study showed that it is feasible to remove dynamite from demolition projects by utilizing pentolite boosters and that when considering safety, explosive properties, and effectiveness, pentolite boosters can be cost effective as well.

Jan 1, 2024

By D. Swanson

Cold Detonation Physics (CDP) is a patented new field of explosives and the name for the explosive that is produced when non-toxic dry ice (frozen carbon dioxide) is combined with powdered metals such as magnesium and aluminum, which are non-toxic and nitrogen-free. The explosive is detonator-sensitive and detonates according to the rapid reduction of carbon dioxide back to carbon, which produces solids comprised mainly of metal oxides and about 5% carbon. CDP was determined to produce a maximum of 300 liters of carbon dioxide per kilogram (4.81 ft3 /lb) and about 1.5 liters of carbon monoxide per kilogram (0.024 ft3 /lb). Both these figures shift according to metal content where higher metal produces less gases. According to theoretical modelling, the relationship between static pressure and metal content was determined to be an inverse parabolic curve with optimum pressure at 25% to 31% metal, depending on the type/s of metal/s used. Velocity of Detonation (VOD) was determined by measuring light at the wavefront with fiber-optic cable inserted into a series of holes drilled into the side of a 3-inch diameter (76 mm) schedule 40 steel pipe containing the mixture. The highest VOD was observed at 25% magnesium and measured between 2,500 to 4,500 m/s (8202 to 14,764 ft/s) when initiated by a 454-gram (1-pound) booster and an electric detonator. A 25% 50:50 alloy of magnesium and aluminum sample shot at a higher velocity than magnesium, according to how the alloy generated smaller pieces of shrapnel when compared with shrapnel from a magnesium test. CDP, using 25% alloy, was tested for blasting limestone by drilling 3.5-inch holes (89 mm) and inserting a 3-inch x 4-foot cardboard tube (76 mm x 1.22 m) with the mixture, packed to a density of 0.62 g/cm3 . The blast was initiated with an electric detonator, behaved like ANFO with more energy and fractured rock sufficiently across the entire length of the borehole. Seismic analysis determined that CDP produces lower ground vibrations than traditional explosives.

Jan 1, 2024

By Steven Putt

The paper presents new results from Datacloud during recent Seismic While Drilling trials in iron ore, metallurgical coal, and hard rock mines around the world. The measurements are compared with wireline geophysical logs, core data, drill cuttings, and conventional measurement while drilling (MWD) systems to validate the technology and show how the data can be used.

Feb 1, 2020