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By R W. Thomas

"This paper explores the possibilities of generating radical improvements in the drihing costs andproductivity of blastholes through the efforts of integrated teams as opposed to traditionalcustomer/vendor relationships."

Jan 1, 1996

By Piet Halliday, Ellina Kharatyan

Conventionally, emulsion matrices (unsensitized) need to be sensitized to become detonable explosives. This is done either chemically or mechanically. Both methods have their advantages and disadvantages. Mechanical sensitization involves the addition of microballoons (plastic or glass) to the emulsion matrix, in order to create hot spots during detonation. This is usually done at the manufacturing site and poses a safety risk in terms of the storage, transportation and handling of a 1.1 type explosive. Many countries throughout the world make use of chemical sensitization as opposed to mechanical sensitization as this allows for the storage, handling and transportation of two 5.1 type products rather than the 1.1 type explosive. Chemical sensitization involves the addition of a small amount of a chemical that reacts with a component of the emulsion matrix causing the formation of gas bubbles that act as hot spots during detonation. The disadvantage of this is the lack of accurate density control (due to various factors affecting the reaction) and the lack of comprehensive understanding of the operators of the reaction. This can easily result in poor blast performance. Due to these disadvantages a pumpable, non-detonable (5.1 type) mechanical sensitizer was researched and developed. This product allows for pumping at a 50:50 volume ratio with the emulsion matrix, when loading into blast holes. The significance of this is that a 1.1 type explosive is formed in the blast hole. As such, the security and logistical issues of the transportation and storage of the 1.1 type explosive are eliminated. Another advantage is accurate density control of the final product, specifically in small diameter long hole applications. A cost effective, unique mini pumping system has been developed for the loading of this product. Moreover, this system can easily be used for secondary blasting applications and the on-site packaging of cartridged explosive products.

Jan 1, 2015

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 Terri Jordan, Gregory Hempen, Thomas Keevin

Water-borne blast pressures from confined blasts were recorded as part of a submerged blasting program in Florida for channel deepening. The blasting was confined within the rock floor by stemming. Shot patterns of stemmed borings were recorded, as were two open-water shots. One hole of one shot was not confined properly, which allowed comparison of confined and a poorly confined larger charge weights per delay. The pressure data were intended to gain information on typical pressure measures from the rock removal program relative to impacts on marine organisms. Water-borne pressures from actual confined, rock-removal shots validate the hypothesis of lessened impacts to aquatic and marine biota.

Jan 1, 2007

Over 45 of the Best Qualified Technical Specialists, Consultants, Engineers, Scientists, Explosive Supplies, Educators and Mine Operators in the World!

Jan 1, 2000

By Stephen Mansfield

In open-pit mining operations, the drill and blast processes have a significant impact on the downstream operational performance of crushing and grinding of ores and recovery of metal. The blast pattern parameters, combined with the material properties, defines the run of mine fragmentation, which in turn drives the subsequent energy requirements for further processing and mill throughput. A common parameter used to describe a single hole or collection of holes is powder factor, the ratio of explosives to the quantity of material blasted. One often-neglected aspect of calculating powder factor is the explosives contained within the length of hole drilled into the top of the bench from the previous bench, known as subdrill. Explosives in the subdrill directly affect the bench below and thus do not contribute significantly to the results of the upper bench, even though they are traditionally included in the powder factor calculation. This paper presents geospatial data modelling methods that link individual holes from an upper bench to the bench below. This enables a new method for the calculation of powder factor, whereby the explosives in the subdrill from the bench above are included in the powder factor calculation of the bench below. This method allows for a clearer understanding of the impact of subdrill on fragmentation, and how variations in blast designs in the upper bench, i.e. hole diameter, burden, spacing, subdrill length, explosive type, primer position, etc., and accuracy of implementation, i.e. actual hole depths and explosive mass per hole, affect the powder factor and blasting results in lower benches.

Feb 6, 2023

By R. Hazael, R. Alford, R. Critchley

The ability to compare explosives is fundamental. Numerous methods are used and while simple conversion factors are often used, the use of TNT Equivalency (TNTe) is not a simple subject as explosives exhibit very different equivalencies depending on whether the pressure or impulse are being considered as well as other conditions. The scaled distance has been found to have a significant effect on the TNTe but due to the difficulty of taking measurements at very close ranges, no TNTe have been quoted for charges in direct contact (Z=0). This paper describes the use of a ballistic pendulum to measure the impulse from contact charges and presents some surprising results that require a two-stage propulsion, as originally described by Backofen, to be explained.

Jan 1, 2024

By Lawrence Mirabelli, AngloGold Ashanti, Greg Gibson

Cripple Creek & Victor Gold Mining Company (CC&V) operates the largest surface gold mine operation in Colorado and is located west of Colorado Springs in Teller County between the towns of Cripple Creek and Victor. Gold was first discovered in the Cripple Creek mining district in the 1890s. CC&V has been conducting gold mining and precious metal extraction operations in the Cripple Creek Mining District since 1976. Current reserves are only amiable to surface mining since previous underground mining has depleted near surface ore rich veins.

Jan 1, 2014

By Jay Smerekanicz, Florin: Pedersen Gheorghiu, Alan Cameron

In order to expand the capacity of Modern Landtill, a groundwater extraction system consisting of a linear system of pumping wells over 2,700 feet long had to be replaced. The new system would be covered by landtill cells to a depth of approximately 400 feet, and therefore would have to be maintenance free. In addition, the new system had to be proven to be more effective than the previous system, groundwater extraction had to be maintained during construction and construction could not disturb either the landfill operation or nearby residential neighbors.

Jan 1, 2001

By Robert Hopler

Testing Stations Abroad At the Seventh International Congress of Applied Chemistry, Drs. Mente and Will communicated a paper on the above subject. All large coal-getting countries employ testing stations of some kind, in order to safeguard, to the highest possible extent, the lives of the men employed in this industry. Most countries employ galleries of considerable diameter, and fairly short length; but within recent times, long galleries, with drives and other accessories approaching as closely as possible the actual conditions of mining have been installed. The following are the details of the testing stations employed in the countries mentioned.

Jan 1, 2010

By Robert Hopler

RBH Note: The Illinois Powder Manufacturing Company was established in 1907 and was acquired in 1957 by American Cyanamid. The latter company left the explosives business in 1969.

Jan 1, 2010

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 ISEE

Micrometer Crack Response to Vibration and Weather, by Prof. Charles H. Dowding of Northwestern University, adds to Prof. Dowding’s already important contributions to the industry with his “Construction Vibrations” books. This new book reports and interprets important data on crack response that are essential for differentiating the unseen effect of weather on structural cracking from the usually much smaller effect of vibration. In addition, the book contains detailed descriptions of data collection methodology.

Jan 1, 2010

By Alyse Munro Hindley

The increasing negative public opinion toward blasting has led to stricter regulations and increased costs. This paper outlines alternative methods of rock excavation and the safety regulations and certification required by blasting professionals. Most importantly, however, it showcases the benefits and accomplishments that controlled blasting bring to society, giving the public a better understanding of the necessity of blasting in modern society.

Jan 1, 2015

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

By L. A. Heim, E. A. McCullough, N. J. Amiotte

The explosives industry is subject to the laws of multiple jurisdictions, which means that several regulatory agencies are responsible for governing different aspects of the commercial explosives industry. Among these regulators are the Mine Safety and Health Administration (MSHA) who implements codes that better ensure both occupational and public safety which is influenced by professional blasting projects and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), who enforces commercial explosives storage and security, among other responsibilities.

Jan 1, 2014

By Thomas L. Barkley

My historic auditing of Underground Drilling and Blasting Practices has demonstrated to the author the need for reviews of many mines' procedures in these processes. Poor understanding of the basic principles and practices of the drilling and blasting science in Underground Development Mining has created significant costs to mining operations in many instances.

Jan 1, 2019

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 Ankit Jha, RICHARD AMOAKO

In this paper, we examine the challenges associated with the use of empirical rock fragmentation models. We highlight key parameters omitted by these models, and propose a machine learning approach that incorporates these parameters, leading to a simple, yet more accurate approach to blast design.

Feb 1, 2020

By Norm Disley, Kingsley Hortin, Gertjan Bekkers

As part of the expansion of the Kidd Creek Mine to 2,682 meters (8800 feet) below surface, two largediameter 3000kW (4000HP) booster fans were installed at the 6000 level. Shortly after commissioning the fans, significant damage to the fan bearings were observed, forcing several shutdowns for repairs, which were very disruptive to the mine’s production process.

Jan 1, 2008