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By Clay McNail, Paul N. Worsey, John Schillie

"This paper is the result of undergraduate student research over the period of 2 semesters at UMR, which was focussed on developing a practical way to pneumatically stem horizontal boreholes, mostcommonly used underground. The majority of dry horizontal underground boreholes are pneumatically loaded with bulk ANFO. ANFO is preferred due to its low cost and the ease of pneumatic loading. However, stemming underground in the United States is a rare practice. In sharp contrast, stemming material (crushed stone or drill cuttings) is virtually always used in surface holes. The purpose of stemming is to increase blast efficiency by containing the explosive energy in the ground and to reduce environmental effects such as air-blast. The problem with stemming horizontal boreholes are; gravity cannot be used to load stemming material and the ANFO does not have a good interface due to problems with withdrawing the hose and the loading itself. This work follows on from Wilkins’ work on stemming angled boreholes."

Jan 1, 1999

By Thierry Bernard

Since the signature hole method principle has been described in the 80's, there has always been a lot of controversy about it. The theory is easy to understand but when it comes to apply it for predicting vibration level, optimizing timing to reduce PPV or shifting frequencies, it’s not always working as expected. Simulations show waveforms that don't make any sense or predictions that are far away from actual results.

Jan 1, 2012

By Robert Hopler

THE work that is being done by the Government to reduce the dangers of mining was brought out strikingly in the First National Mine-Safety Demonstration which occurred at Pittsburgh, Pa., on October 30th and 31st, under the auspices of the United States Bureau of Mines with the assistance of the American National Red Cross Society and the Pittsburgh Coal Operators’ Association.

Jan 1, 2012

By Emily Johnson, Catherine Johnson, Rachel Bauer, Paul Pitzel

Demolition projects involving explosives may incorporate cutting charges to sever columns in collaboration with kicker charges that “move” the columns out of alignment. Traditional kicker charges often involve the use of dynamite secured to the column above the cutting charge. Nitroglycerine, the main component of dynamite, causes medical problems and can be a hazard to workers on site. Dynamite can also cause fragmentation of the column and structures, resulting in potential injuries to people or leading to the possibility of cutoffs in neighboring charges. This study investigates the use of water-cased kicker charges to reduce the amount of dynamite in demolition. Water charges, traditional charges, and detonating cord charges were placed on hanging steel columns and analyzed for the fragmentation of the column and velocity of the column. A W 10 X 22 beam was hung in an underground limestone test area and allowed to swing freely acting as a severed column. Charges were attached to the bottom of the column with tape and initiated using electric detonators. Explosive charges of dynamite or detonating cord were placed in the center of a water container or directly on the column for use as the kicker charge. Tests were recorded with high-speed video and velocity was calculated using Phantom Camera Control software. Velocity and time were then used to calculate force, kinetic energy, impulse, and pressure exerted by the explosive on the column. The water charge transferred energy to the column over a larger area with no direct contact of explosive and the column. Water charges moved the column faster and with more power than traditional charges. After preliminary tests, water charges were also used as the primary kicker charges in a full-scale demolition project as a case study using 118 charges. The kicker charges successfully moved building members without creating fragmentation while using less dynamite than traditional kicker charges. Due to the success, multiple full-scale projects are being designed using water charges to show success and repeatability.

Feb 6, 2023

By Dale Preece, Joergen Pilz, Zavis Zavodni

An overland conveyor was constructed at a surface coal mine to reduce the truck haul distance and make the operation more efficient. An important element in this system is a truck dump facility to transfer coal from truck to conveyor. Mechanically stabilized earth retaining walls were employed to accommodate the coal processing equipment, including the crusher, in this facility. These retaining walls are close enough to the pits being mined that blasting induced vibrations must be considered in analyses of the wall structural stability.

Jan 1, 2010

By Mauro Fornaro, Marilena Cardu, Renato Mancini, Daniele Castano

Tunneling by explosive blasting in civil works isn't merely intended to break somehow a way through the rock, rather to drive a permanent, constant cross section, lined way. The current mechanical excavation v/explosive blasting debate is mainly centered on the concept of the tunnel wall quality; and consequently explosive blasting strategy is founded on contour blasting.

Jan 1, 1992

By Gregg R. Gitschlag

There are more than 4,000 oil and gas structures present in the U. S. Gulf of Mexico. Approximately 100 structure removals occur each year and 66% of these are removed with explosives. From 1993-1995 an intensive study was conducted on the fish kill resulting from the explosive removal of 6 platforms off the Louisiana coast in water depths from 14-28 m (45-92 ft). After explosives were detonated, all floating fish and a sample of the dead fish which sank to the sea floor were collected.

Jan 1, 1997

By Tom Watts

This paper will focus on the design, manufacture and use of pump safety systems on MMUs (Mobile Manufacturing Units – Bulk Trucks) with progressive cavity pumps. The practice of pumping bulk blasting agents is highly regulated and the explosives manufactures have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping.

Jan 1, 2009

By Elliott Giles

"Measuring a blast’s performance based on the bucket fill time or “diggability” has always been achallenge due to the subjectivity generally involved. The diggability of a blast is often based onopinions and speculation without the data to properly support the claim. This paper focuses howthe blast design can impact diggability and how it can be properly measured."

Jan 1, 2016

By Kirk Yeager

All explosive formulations display some sensitivity to heat. A common technique utilized to measure an explosive’s response to thermal stimulation is differential scanning calorimetry (DSC). As DSC analysis is run on quantities of material easily handled in a laboratory setting, and is relatively inexpensive, it tends to be one of the more predominant tools utilized to determine potential thermal hazards of energetic materials. The analysis of energetic materials via DSC provides unique challenges, as both large energy outputs and significant production of gaseous products result from their decompositions. In addition, the unique thermal decomposition characteristics of ammonium nitrate (AN) based materials have also created difficulties in DSC analyses. A wide variety of techniques have been developed to study the decomposition of explosives. Traditionally, sealed glass capillaries were utilized to house samples. Recently, the introduction of specialty cells designed to withstand high pressures has enabled new sampling techniques to be developed. Analyses of explosives with both traditional and “high-pressure” cells will be compared and contrasted. Lessons learned about the application of both techniques towards analyzing thermal hazards such as incompatibilities will be presented. Inconsistencies in the results displayed during analyses of AN-based explosives will be highlighted. Recommendations on the best approach for analyzing the more problematic AN formulations will be given.

Jan 1, 2000

By Magnus Gynnemo

The primary purposes of drilling and blasting in hard rocks is to fracture solid rock and prepare it for excavation and subsequent transport to the crushing plant. Using explosives in excavation operations without counting for the geology gives no consideration to the quality of the macadam product or the excess production of waste material (fines).

Jan 1, 1997

By Greg S. Williams, David L. McDorman, Richard W. Givens

This paper examines the effect of prill size consistency, internal particle density, and oil absorbency on Ammonium Nitrate Fuel Oil (ANFO)-emulsion blends. By analyzing these physical properties of prill and the nature of the blending process, a mathematical model has been developed to theoretically predict blend densities. Calculated densities can now be compared to actual field densities to give an operator a basis for comparing various manufacturers' emulsions and Ammonium Nitrate (AN) during bid solicitation. The lowest priced emulsion and/or AN may not be the most economical, due to the impact of specific physical characteristics. These factors dictate the blending mechanics and resulting density yields for various mixes. The research was driven from observed 'field' mixing relationships and data. Ultimately, such a model can be an effective tool in evaluating blends from a cost and performance basis.

Jan 1, 1990

By Lawrie Logan, Mike Wiggin

This paper will be in two parts, a discussion of the benefits available from benefit sharing as a concept followed by an examination of how this approach was applied at Mesa J Mine and what improvements were made. The first part is an outline of the ways that both parties in a benefit sharing agreement can uncover additional wealth by bringing a new approach to the relationships between mine and supplier. The paper describes a partnering agreement recently established between Robe River Iron Associates (RRIA) and Dyno Nobel Asia Pacific Ltd (DNAP) to access the wealth locked up by the usual explosives supply contracts in Australia and elsewhere. The partners are acting cooperatively to maximise the benefits to both parties from optimising blasting practices at the Mesa J Iron Ore Mine in the Pilbara region of Western Australia.

Jan 1, 2001

By Tristan Worsey, John Rathbun, Andres Malone

A run of mine, low grade gold heap leaching operation is currently looking to increase ounce recovery by decreasing run of mine fragmentation size. Current blasting practices have resulted in an average fragmentation size of 80% passing 7.05 inches (179 mm). It is estimated that a decrease of 2 inches (51 mm) in the 80% passing fragmentation size has the potential to yield up to a 2.5% increase in the overall life of mine recovery within this ore body. This potential recovery increase could lead to an increase in recoverable ounces which, in turn, would lead to a better profit margin. As this particular deposit is composed of predominantly low grade heap leach the capital investment in a crushing facility was cost prohibitive, it was therefore decided to look into the current blasting practices as a means to improve fragmentation.

Jan 1, 2015

By Jeffrey W. Lin, Larry B. Weston, Jonathan D. Abbott, Jordan L. Arthur

Hydrocarbon fuel oils are one of the main components of ammonium nitrate-based explosives, including ANFO (Ammonium Nitrate-Fuel Oil) and emulsions. While a wide variety of fuels can, and have, been used in the manufacture of ANFO and emulsion products, No. 2 diesel, particularly dyed, off-road diesel, is widely used due to its ready availability and use in fueling mining equipment. However, a number of alternatives to standard diesel have been introduced over recent years, namely, biofuels, ‘high-performance’ diesels, and renewable diesels. The pressure to adopt these alternative fuels come from a variety of sources, such as initiatives to reduce carbon footprints, increased lifetime of equipment, and cost-advantages from tax credits. While these factors may provide a very real benefit to the mine site, a consideration that is often missed is how the use of these fuels can impact the formulation and characteristics of the ammonium nitrate-based explosives. Herein will be presented a discussion of these alternative fuels from a chemical perspective as well as the results of several studies focused on how the inclusion of various alternative diesels influences the production and performance of ammonium nitrate explosives. ANFO and emulsion were manufactured using representative fuel sources and studying in terms of the manufacturing parameters, shelf-life, interaction with other chemicals using in mining explosives. Detonation data was then collected for these products and compared to the behavior of products made with standard diesel fuels.

Jan 21, 2025

By William A. Travnik

For more than 60 years, ESSO RESOURCES CANADA LIMITED has been producing and refining oil at a small refinery in Norman Wells, Northwest Territories, and supplying diesel fuel and other oil products to northern markets. In 1982,ESSOwas granted governmental approval to expend production from the oil field from 475 cubic metres a day to 4400 cubic metres a day. This $800,000,000projectproceeded ahead of schedule for a start up in 1985.

Jan 1, 1986

By Paulo Cesar Pavan

T&T or Traceability, is a concept of generating, storing and on demand providing information about all traceable items in the supply chain

Jan 1, 2019

By Jhon Silva

"Signature Hole and Waveform Superposition techniques used to predict and control mine blast ground vibrations require a clearly defined information collection configuration. The collection of this information determines the scope and success of the ground vibration prediction. Application of the Improved Signature Hole technique using the Silva-Lusk equation requires the collection of at least two informational elements from any specific production shot. The first required element is a signature waveform, and the second element is the overall production blast waveform. The signature waveform depends on detonated charge variables such as the amount of explosive in use, use of decking, the possible detonation of several holes at the same delay, and many others. The production blast waveform is beneficial to the Improved Signature Hole methodology when used to calibrate the model, and toobtain accurate vibration predictions for different timing configurations."

Jan 1, 2017

By Steve Collinsworth

Sometimes, for those of us in the right place at the right time with the right product, necessity creates opportunity. Such is my case at a West Virginia coal mine where a mine manager was desperately seeking a way to eliminate coal damage on cast shots while maintaining cast percentage without the expensive process of secondary drilling. This paper will focus on how bottom hole air decking is solving the problem.

Jan 1, 2000

By Kim Henley, Chris Batten

This paper discusses the use of the Orica WildFireTM flyrock model to help mining operations in Australia and Asia minimise blast exclusion zones for equipment, increasing utilisation and productivity and delivering downstream value

Feb 1, 2020