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By Jerry Bennett

A recant Bureau of Mines analysis has shown that failure of blast area security systems is the mayor cause of mine blasting accidents. Accidents occur during scheduled blasting because of failure to clear the blast zone, inadequate guarding, and failure of personnel to follow instructions, retreat to a safe location and/or take adequate cover. The high incidence of blastslte security-related accidents could be considerably reduced by increased attention to improving minesite blast-guarding practices.

Jan 1, 1984

By T Barnes, K D. Sexton, T J. Tope

For the past decade, the U.S. Department of Defense (DoD) has been under increasing pressure from state and federal regulatory authorities to develop management strategies for waste streams generated at its bases, installations, and ranges. Since passage of the Federal Facilities Compliance Act (FFCA) in 1992, concerns have focused in particular on military munitions and energetic waste streams.

Jan 1, 1997

By Hairong Zeng, Shahram Tafazoli, Edmond Chow

Blast fragmentation is one of the main parameters for optimizing mineral processing, but reliable data is difficult to acquire, resulting in unpredictable performance and efficiency. Crusher and grinder circuits are designed to process specific rock size ranges. Oversized rocks require extra energy to reduce before feeding into the process, and undersized rocks indicate that the process is not used to its full extent. Blast design is the key to controlling the blast fragmentation, so the ability to accurately monitor the particle sizes is imperative.

Jan 1, 2011

By Tuan Nguyen, Dirk Hummel, Ruilin Yang

In a tunnelling site in Japan, it was found that detonators failed to initiate with their shells and primary explosive intact. Their capacitors, however, were discharged due to some damage on the application-specific integrated circuits (ASICs). These detonators are distinctly different from other commonly observed failures, where the shells are rather crashed due to excessive dynamic pressure received from neighbouring blastholes which fired earlier. Such incident has not been reported elsewhere. Detonator failures during a blast are deemed not safe and can cause disruption on the project productivity. It is therefore desirable to understand the origin of such event. Various measurements were conducted to diagnose the problem, but the root cause had yet to be identified. This paper applies a discovery from a 60-year-prior-laboratory experiment and formulates a theory that could explain the observed detonator failure and predicts the measurements and observations.

Feb 6, 2023

By Lloyd Litwin

The ARTA 2008 Project (Alpha Ridge Test of Appurtenance) was a Canadian Government sponsored deep water seismic survey carried out on the high arctic permanent polar ice cap. This Geological Survey of Canada operation was the second seismic research project in the high Arctic and was monitored by the Danish Government. Utilizing 100% air support from Eureka and then helicopters from an ice based tent camp north of Ellesmere Island, the five week study was accomplished in the early spring just after the sun returned to the far north.

Jan 1, 2011

By Agne Rustan

This paper is intended to give a summary of the first ten Symposia on Rock Fragmentation by Blasting where the symposia activities were governed by a Steering Committee replaced at Fragblast 2 by an International Organizing Committee (IOC). At Fragblast 9 the name was changed to Fragblast International Organizing Committee (FIOC). Eighty four pages of statistical data about Fragblast 1-10 is documented on the Fragblast Website (ISEE.org).

Jan 1, 2014

By Muhammad Yamani, Marsell Riviera, Herry Saputra, Rizky Amin

Drill and Blast processes in hot and reactive ground conditions are a severe challenge in mining, especially in the blasting process. Our main objective is safety issues without compromising the blasting outcome. Safety concerns include unexpected detonation, product damage, and misfire. However, apart from the issue of blasting safety, it is also crucial to maintain good results such as fragmentation, loader productivity, and ore dilution control. Therefore, we use a different product selection method to produce a safe and efficient blast. Pit Araren is one of the pits of the Tokatindung Gold Mine Project in North Sulawesi Province, Indonesia, classified as hot and reactive ground conditions that range from elevation of 25mRL temperature could reach to 98⁰C (208,4⁰F) based on actual measurement. The previous practice for blast holes with temperatures above 70⁰C (158⁰F) loaded with the primer that was specifically designed for hot and reactive ground conditions consisting of detonating cord and packages emulsion that specifically formulated to inhibit exothermic reaction then tied in with a combination of non-electric surface delay detonator and detonating cord initiator (short length non-electric surface delay detonator housed in plastic connector).

Feb 6, 2023

By Alejandro Berrios, Matheus DaSilva, Erick Siqueira

Vazante mine is an underground polymetallic mine that produces zinc, lead, and silver, which belongs to Nexa Resources in Minas Gerais, Brazil. The mine, a sublevel stope underground mine, mainly applies two subvariants: VRM – Vertical Retreat Mining and Open Stope. In a specific place of the mine, the geology allowed the design of a production stope with larger dimensions than the standard stopes, commonly called Super Stope. At this place, the plan was to apply both sublevel variants simultaneously. This mining block comprises rings in two different levels, with access by two ore drives on each level; the dimensions would be approximately 50 meters high, 50 meters long, and 35 meters wide. Opening the Free Face to mine the whole Stope was a challenge due to operational issues, such as hazard risks from loading over void space, exposure to uncontained places, and the impossibility of implementing the optimal blast sequence. Wireless blasting initiators have gained popularity recently due to their convenience, safety, and efficiency. This initiation system was applied to preload all the rings required to open the Free Face, ensuring a safe and optimal blast sequence. Wireless initiation prevented hazard risks, enhanced the blast sequence to guarantee the required void space, and optimized the equipment's operational cycle. The blast crew carried out the activity without exposure to the risk of loading over void space. The wireless detonators also avoided after-blast activities, which were required to provide secure access to the blast crew, optimizing the operational cycle.

Jan 21, 2025

By Douglas A. Anderson

The US Bureau of Mines, in RI 8507, has shown that blast vibrations at low frequency are more likely to cause damage and complaints than those at higher frequency. Since that publication in 1980, the Office of Surface Mining and many state and local regulatory authorities have incorporated frequency in their regulations for acceptable ground vibration from blasting. Even when frequency is not explicitly stated in regulations, it may become an issue in hearings or in court.

Jan 1, 1992

By Art Frye, Lee Pratt, Gaichang Zhao, Greg Newman

This paper will discuss the Wight Pit wall slash at the Mount Polley open-pit copper-gold mine that scavenged a high grade block of ore from two double-benches of the pit wall. The Wight Pit orebody, discovered in 2003, is located in the Northeast of the property with the southeast pit wall approximately 50m (165ft) from the edge of Polley Lake. In early 2009, the Wight Pit was nearing completion while an estimated 150,000 tonnes (165,000 tons) of ore averaging a grade of 1.4% copper remained just inside the southeast pit wall. The ore block started 24m (78ft) above the pit floor and extended up another 48m (157ft) with a 70o plane defining the back of the block.

Jan 1, 2011

By D. Fry, S. Hunsaker

Ammonium nitrate in explosives and sulfides in reactive ground have the potential to react at ambient and elevated temperatures resulting in premature detonations. The Australasian Explosives Industry Safety Group (AEISG) published, in 2006, a Code of Practice1 for elevated temperature and reactive ground. This paper reviews the chemistry, general reactivity of various ground types, elevated temperature hazards, and testing protocols contained in the code, that are industry best practices for managing ammonium nitrate-based explosives in elevated temperature and reactive ground conditions. In addition to reviewing the 5th edition AEISG Code of Practice, data is presented validating the recommended sampling guidelines within the code. Dyno Nobel has been screening reactive ground samples and performing sleep time testing since the code of practice was first released. Test results demonstrate the effects of samples that are allowed to oxidize before testing and are shown to be subsequently less reactive and not representative of the actual hazards facing mining blasting operations. Results also show that for a given reactive ground sample, reaction times decrease with increasing temperature. Data also quantify the delay in reaction time given by inhibited products. These results emphasize the importance of proper sampling and preparation of samples to accurately characterize elevated temperature and reactive ground hazards. They also demonstrate the efficacy of inhibited products in managing these hazards

Jan 1, 2024

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 PHILIPP HARTLIEB, Peter Schimek, Thomas Seidl, Pablo Segarra, José A. Sanchidrián, Juan Navarro

This paper develops a new Blastability Index to assess hole-to-hole fragmentation in bench blasting based on a new Rock Factor exclusively obtained from drill-monitoring data, that can provide an automatic assessment of rock structure, strength, and waste/ore, the effective energy factor of the explosive and the delay time per blasthole.

Feb 1, 2020

By Martin Langenderfer, Catherine Johnson, Phillip Mulligan, Kelly Williams

The physical geometry of a charge has a direct correlation to the geometry of the shock wave. This relationship appears strongest within the boundaries of the visible fireball. As the shock wave propagates outward past the limits of the fireball, the theory states that the geometry of the shock wave should even out and become more spherical. This paper investigates pressure vs. time at two distances, one ‘Near Field’ at the extent of the fireball and one ‘Far Field.' The two Fields were instrumented with three free-Field pressure probes from PCB oriented at 0, 45, and 90 degrees to the front face of the charge, in the same horizontal plane as the charge. This orientation allows for the comparison of the shock wave from the face and vertices of the charge. All the pressure sensors were connected to a Data Acquisition System (DAS) recording at 2 million samples per second (2MS/s). Two high-speed cameras, a Phantom and an MREL Ranger II, recorded the detonations for qualitative examination of the fireball, and the shock wave. Three charge geometries were used and compared to the shock propagation of a sphere. The other geometries tested are cylinders, cubes, and tetrahedrons. Charges were made from a PETN based sheet explosive. In the Near Field, a lower pressure is observed along charge vertices with highest pressures from each face. In the Far Field, vertices record a higher pressure, possibly due to the shock waves from the adjacent faces intersecting, indicating that shock pressures do not always even out in the Far Field. This paper will describe the methodology and findings of this experiment and attempt to determine causality for trends in the data gathered.

Jan 1, 2018

By Charles Zdazinsky

Many blasting applications in the mining industry demand that the hard rock being blasted remains structurally competent. For example, pre-splitting is a common technique to reduce fracturing, and operators of dimension stone quarries use this blasting method to eliminate overbreak. When pre-split design parameters are not applied correctly, there will be a redistribution of stresses within the rock, resulting in Blast Induced Rock Damage (BID). Advances in geophysical technology are enabling blast technicians to monitor BID and then use the results to correctly design their blasts.

Jan 1, 2011

By Dr. Anurag Agrawal, Steve Franklin, Clint Zimmerman, Elijah Williams

In a time when data has become a highly valued commodity within many mining and quarry operations, managing large amounts of current and historical information can be difficult. If not managed properly, trying to leverage the data to make informed operational decisions promotes another challenge. Geographic Information System (GIS) is an environment that uses computers and software to create, manage, analyze, and map all types of data. Currently, the mining industry is faced with a challenge to produce the demanded critical metals and minerals that drive our economies. GIS is leveraged in many large mining industries today to help drive decisions, save cost and plan for future operations. Specifically in the Drilling, Blasting and Quarrying industries, data is being captured at many different levels, whether it is a subsurface geological, blast performance, quarry surveys, loading and hauling, or crushing performance. Pen and paper logs and reports compiled lack the dimension that GIS can bring for extracting value from real-time or historical data. GIS connects data to maps, integrating location data with all types of descriptive information. Paired with Artificial Intelligence, additional analytical layers can be built on platforms to extract data and automate workflows. Having the ability to encompass several forms of collected data to drive operational decisions can bring huge savings to the bottom-line. This paper will dive into the areas where GIS data can drive value into operations by assisting in the management and analysis of the types of data being captured, specifically with Drill and Blast. Whether it is tracking haul road conditions, monitoring locations of equipment, environmental conditions, quantifying blast performance or developing a quarry plan based on geological models. GIS can collectively encompass all of this data to bring tremendous value to the operations, improving safety, efficiency and production.

Jan 21, 2025

By Thomas C. Rube, T S. Bajpayee

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs.

Jan 1, 1996

By Elliott A. Pood, Ron Gilbert

Recent advances in digital recording technology have allowed frame rate increases in video recording equipment that provide the capability for super slow motion playback of commercial explosives shots. Such slow motion playback allows for the analysis of shot patterns, cap scatter, pattern failures, etc. In addition, the availability of such materials on video tape enables commercial blasters to provide a means for training current and future staff.

Jan 1, 1996

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 Bilegt Batbold, Bayu Saputra, Chris Batten

The ability to fire multiple blasts simultaneously can provide significant benefits to any open pit mining operation. Reduced blast-related downtime by reducing blast events can increase equipment utilization and maximize material movement. Significant sequencing benefits can also be delivered, associated with reduced equipment relocation. This paper describes the work completed in partnership between Orica and Oyu Tolgoi to successfully demonstrate that combined production-trim and midsplit blasting could be implemented successfully while successfully managing the risk of increased damage to the final walls. The paper details the methodology used to assess key performance measures linked to final wall damage and compares the performance between the following blasting methods. • Free face trim blasting vs. combined production-trim blasting • Presplit blasting vs. midsplit blasting. The results of the initial trial blasts are presented, along with the method agreed by the key site stakeholders for ongoing application. The method used to keep the risk of final wall damage to an acceptable level is explained, along with the benefits delivered to Oyu Tolgoi operations associated with the initial 12 months of application.

Jan 21, 2025