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By Donald Hurd, James Rowland, Richard Mainiero

In previous conferences the authors have reported on toxic fumes generated by the detonation of ANFO. The research reported here extends the earlier work to include an emulsion blasting agent and ANFO/emulsion blends. Explosive mixtures were shot in 4-inch Schedule 80 steel pipe (outer diameter 4.50 in (11.43 cm), inner diameter 3.83 in (9.72 cm)) in a chamber in the experimental mine at the Pittsburgh Research Laboratory (PRL). Following each shot, the fumes in the chamber were analyzed using on-line instrumentation.

Jan 1, 2001

By BruneJurgen F., Richard C. Gilmore, Matthew Schreiner, Ray Johnson

Explosive pockets of methane-air mixtures accumulate in underground coal mines and, when ignited, produce an air-blast wave that can disturb combustible coal dust on the floor, roof, and ribs. To prevent explosions, the coal dust must be continuously diluted through application of inert rock dust, usually powdered limestone. Application of powdered dust process creates a respiratory nuisance downwind, where miners cannot work until the dust settles. Rock dust suppliers have developed wet and foam applied products to reduce the nuisance and limit the interruption to mining during dust application. To test the effectiveness of these alternative dust products, researchers at the Colorado School of Mines (Mines) have constructed a full-scale explosion test drift located at the Mines Edgar Experimental Mine (Edgar) to study the dispersibility of different rock dust applications. This paper examines the use of Pentaerythritol tetranitrate (PETN) detonating cord to produce controlled air-blasts that simulate methane-air explosions. The air blasts are generated with curtains of detonating cord that produce shockwaves with wind speeds between 30 to 70 m/s (100 to 225 fps) depending on the length of 5.3 g/m (25 grain/ft) detonating cord used. These velocities represent the minimum air speeds required to trigger propagating coal dust explosions. Researchers have conducted 40 test blasts with various lengths of detonating cord. Results show the two primary waves and two reflected waves each decaying into airblast waves with overpressures of 14 to 27 kPa (2 to 4 psi). Pressures were recorded with commercial piezoelectric transducers and custom-built, bi-directional probes to record the total and dynamic pressures of the wind generated in the explosion. Researchers were able to generate consistent and repeatable wind speeds and air-blast durations sufficiently similar to a methane-air explosion to study the dispersibility of various rock dust products and application methods

Jan 1, 2019

By Diego Quezada, Carlos Munoz, Marco Arellano

It is well-know that the presence of fine materials in mining has a direct impact on the plant processes with a great influence in the total amount of ore production and recovery. In Cu mining heap leaching is affected negatively by the presence of fines material (< 100 # Ty) in leaching piles, where a decreasing in Cu recovery is achieved in a lot of cases. D&B practices used normally in mine operations can generate fines > 4% in blasted piles, but the principal effects are reflected in the downstream processes where pre-conditioning post-blast materials release greater quantities of fines.

Jan 1, 2010

By Orica

Unlicking the Possibilities ISEE Digital Detonator Workshop New Orleans, LA Wednesday, February 4, 2004

Jan 1, 2004

By Luana Ferreira de Carvalho, Aurelio Manço Garcia, Gustavo Sampaio Lopes, Jose Silvio Corsini, Davi Bastos Martins de Oliveira

The Enaex Mining Technical Solutions (EMTS) team, in partnership with the Anglo American Iron Ore Brazil drilling and blasting team, has developed a study aiming to optimize the blast design applied at the Minas-Rio project. The study consists of modeling the dynamic behavior of one lithological domain to determine the best configuration of drilling pattern, charge configuration, timing and sequencing of the blast designs applied at the mine in this particular rock.

Feb 1, 2020

By Jack Eloranta

To improve control of blasting, tests were performed to assess non-electric cap accuracy. Simultaneous testing using a Velocity of Detonation Recorder (VODR), Red Lake LoCam and an Instantel DS-677 blast monitor was done. Favorable comparisons were found in the three records. This testing confirmed the accuracy of an inexpensive and expedient cap testing procedure.

Jan 1, 1992

By Chanhwi Shin, Hyeongmin Kang

Mine optimization is a key strategy in the mining industry that focuses on improving the efficiency, productivity, and sustainability of mining operations. To achieve mine optimization, digitalization is essential for modernizing mining operations and attaining optimal performance. Due to the importance of mine digitalization, various software and platforms have been released to support this effort. Furthermore, by integrating these advanced technologies, mines can enhance processes, leading to significant economic and operational benefits. However, integrating data from various sources and collaborating across different platforms remains a significant challenge in the mining industry. Generally, data for mine optimization, such as mapping, smart drilling, FMS (Fleet Management Systems), fragmentation analysis, or vibration analysis, are collected and analyzed separately on different platforms. This separation makes it difficult to aggregate and utilize data comprehensively for overall mining process optimization. During the digitalization process, obstacles arise due to these complexity, variability, and sharing issues of data across different maker, sources, and methods. These challenges highlight the need for seamless integration to achieve optimal mining operations. Thus, this study applied a total solution that can cover the entire Drilling and Blasting (D&B) processes. The blast design was performed using actual terrain mapping data, and drilling and charging were conducted following a guide based on the blast design plan. After blasting, loading and hauling distances and fuel consumption were measured, and fragmentation for each blast was evaluated. All measurement tasks were automated to minimize human error. By collecting all data in one server, it became possible to perform an overall evaluation for each blast, allowing the identification of optimal values. In conclusion, to evaluate the optimization effects for each mining process, one month of integrated data collected on a single server was used. Compared to the period before the Total solution was implemented, there were notable improvements: a 25% enhancement in hole spacing, a 60% improvement in floor flatness, a 23% reduction in average fragment size, and a 19% improvement in fragment uniformity. Regarding cost savings per blasting volume, the improvements were 11.7% in drilling, 9.3% in explosives, 7.6% in loading, and 17.5% in hauling.

Jan 21, 2025

By Dominic C, Gregory B. Poole

On December 12, 2018 at 4:14 AM EST, an earthquake registering a 4.4 magnitude on the Richter Scale occurred in central Tennessee. According to a survey posted on the USGS website, this earthquake was felt throughout the southeast and even as far away as Arnold Nebraska. That’s over 900 miles (1,448 kilometers) from the epicenter. We recorded the vibrations from this earthquake on 44 different seismographs that were set up with remote access to continuously monitor vibrations from blasting activities. Having this data gave us an opportunity to compare the vibrations caused by earthquakes and blasting. A simple observation of the amplitudes, frequencies, and durations is enough to notice that vibrations from earthquakes are very different than vibrations caused by blasting in mining and construction

Feb 1, 2020

By Steven Richardson, E A. Cameron, Reza "Ray" Jambakhsh

This paper outlines the design and implementation of a method to use Long hole Carbide drilling to blast an "Upper Blind Slot Raise" in the range of 12m (40 ft).

Jan 1, 1992

By Tom Goodell, James Cox, Scott Scovira

Resolution Copper Mining is sinking a 6943 foot (2116 m) deep shaft to access and develop a new panel caving mine with approximately 1.6 billion known tons of porphyry copper resource. This mine will take several years to ramp up to its full production level of 132,300 tons per day (120,000 tonnes per day) and is scheduled to begin production in the early 2020s. Resolution's shaft sinking contractor Cementation USA is using state of the art sinking methods combined with a largely local labor force to complete this record breaking shaft. Resolution's No. 10 Shaft has finished diameter of 28 feet (8.5m) and as of October 2013 is at the 6625 foot (2020 m) level. Upon completion in early 2014, the No. 10 Shaft will be the deepest single lift shaft in the United States.

Jan 1, 2014

By Tom Watts

Bulk Security Best Practices

Jan 1, 2006

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 Paul Worsey, Matthew Coy

In the blasting industry, many different techniques are used to estimate and examine the effects of varying explosives and blast designs on the breakage of a rock mass. The overall objective is to find a cost-minimized blasting solution that also conforms to the legal and environmental concerns related to blasting. A major drawback to current blasting methods is the inability to account for "caprock," or a thick overlying layer found in sedimentary rocks that creates large amounts of oversize blasted material, especially on the top of a muck pile. This can lead to underestimating oversize in shots with massive top layers. A better fundamental understanding of blasting processes with caprock is required.

Jan 1, 2018

By Francisco Sena Leite, Thomas Palangio, Vinicius Miranda

With an increasing pressure to find efficiencies in the mining industry, operations are looking for continuous improvement tools to validate blasting procedures, a crucial and often overlooked area of the process. Using case studies completed at both small and large-scale mining operations, this technical paper proposes a practical methodology for pattern expansion studies, taking into account terrain parameters, rock quality and explosive strength. This technical paper will use a series of tools geared towards an economical continuous improvement procedure, using UAV particle size analysis to optimize blasting based on “generalized reduced gradient” for non-linear problems, with cost savings being the main objective. For the validation of this methodology, one scenario was created based on the operation’s budget: an economical continuous improvement plan that relied on manual data collection methods in order to baseline and optimize procedures.

Jan 1, 2018

By Stewart A. Silling, C. Mick Lownds, Dale S. Preece, Ali Bhuiyan

GEM (Geologic Element Motion) is a Distinct Element Method (DEM) for modeling blast-induced heave. It was developed with a very fast computational algorithm that efficiently treats many different element shapes utilizing alternating arcs and lines to create GEM elements. The GEM computational technique has been previously documented so only a summary will be included in this paper. New features of GEM are the ability to define the size of the rounded corner radius as well the length of the sides for quadrilateral and hexahedral elements. Circles can be created from a quadrilateral element with zero length sides and four arcs. An additional new GEM feature is energy partitioning between brisance and heave. This physics-based partitioning is essential for accurate modeling of blast results over a wide range of rock and explosive types. It accurately defines the volumetric, pressure and energy state of the explosive gases in a blasthole following detonation. Rock mechanical properties and explosive characteristics are included in the calculations. Example simulations provide comparison of the GEM predicted heave for two different classes of explosive. A GEM simulation utilizing hexahedral elements is compared with previous modeling incorporating circular elements.

Feb 6, 2023

By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan, Alper Celtikci, Serdar Celik, Yucel Karakus

This paper presents bench blasting designs based on results of vibrations analysis on test shots organized in an open pit coal mine located near to Soma district at Manisa province in Turkey. There are some structures which can be adversely affected by blasting at the coal mine. The one of the main goals of this study is to perform a preliminary assessment of possible damage effect of ground vibrations induced by blasting at these structures by risk analysis based on ground vibration measurements. During this investigation, the data pairs of scaled distance and particle velocity obtained from the 36 event records belong to 9 test shots were statistically analyzed and a PPV prediction equation specific to this site with 95% prediction line were obtained. And also, this equation was used in the derivation of the practical blasting charts specific to this site as a practical way of predicting the peak particle velocity and maximum charge per delay for future blasting. A risk analysis was performed by using this equation. In the light of this analysis, preliminary blast design model was proposed to be used in this coal mine for overburden excavation.

Jan 1, 2012

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By S. S. Jenkins Jr.

While the method is seldom used anymore, coyote blasting is an historically interesting way to blast large quantities of rock. It was used extensively in the days before modern fast drills were available and can be very effective in some formations that have a natural breakage pattern. This paper will cover the general principles, some blast design factors and point out several actual blasts including some very large ones.

Jan 1, 2005

By Anderson Meireles, Leonardo Soares Chaves, Raul Carretero Hoz, Carlos Eduardo Soares Feliciano, Renato Jacome Costa

The large iron deposits in the northern region of Brazil located in the Amazon Craton have in common the presence of natural cavities. These cavities primarily occur in the upper layer of the ore body, formed above hematite mineralization. Their origin remains a topic of debate, often associated with hydrothermal drainage processes and erosive evolution. Over time, these cavities have become integral to the local environment, each contributing to the regional ecosystem of fauna, flora, and the significance of speleothems found within them. Managing these cavities poses a significant challenge for iron mines in the area. On one hand, they must preserve the cavities from anthropogenic actions, while simultaneously handling heavy equipment and large volumes. In 2023, the development of the mine took place towards the cavity under study, revealing systematic deviations in vibrations recorded during nearby detonations as the blasting got nearer. To address this, a work plan was put in place, emphasizing a straightforward approach: constructing lithology-specific vibration models, defining charge abacuses, and optimizing timing to reduce charge amplification. Implementing this methodology significantly improved adherence to the vibration limit, resulting in an around 50% reduction in standard error. This paper presents the consolidated work that allowed mining activities to continue in the area through controlled blasting, effectively mitigating potential anthropogenic damage in sensitive areas.

Jan 21, 2025

By Roland Alford

The ballistic pendulum is a well-established piece of test equipment originally developed for estimating the velocity of bullets and projectiles. When trying to understand the effects of different tamping methods on explosive performance, the ballistic pendulum is an excellent tool allowing calculation of explosive charge impulse. Most ballistic pendula for this application are limited to narrow impulse ranges as the pendulum mass determines the angle of swing; and a mass capable of being moved by a small charge would be far too small for a larger charge. This paper describes a modular design (the Alford Modular Ballistic Pendulum) which overcomes this problem.

Feb 6, 2023