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By Raúl Carretero de la Hoz, Leonardo Soares Chaves, João Paulo Soares Toneli, Francisco Felipe da Silva Dantas, Marcos Peres Lopes, Marcus Vinicius da Silva Gonçalves

The mining activity results in environmental impact and thus requires the adoption of techniques to minimize its effects. The rock blasting process is required to break up and move the rock enabling the haulage of the material, however, it might also cause undesirable effects such as flyrock, overbreak, excessive ground vibration or air-blast at the neighboring communities and damage to civil or geological structures located nearby. The Serra Sul mine, commonly referred to as S11D project, has obligations to preserve two natural tropical montane lakes and several maximum relevance natural cavities whose legal preservation radius represents constraints to the mine development and operation. Controlling measures are undertaken to ensure preservation of the cavities, especially during rock blasting stage, with limitations of the maximum instantaneous charge (MIC) and ground vibration control. The demand for high productivity and the large areas with hundreds of blastholes to charge are challenging factors to the charge control. This work presents the development and field application of a map for limiting explosive charges in the rock blasting process at the Serra Sul mine, used for the definition of maximum charges according to the blast location, ensuring the preservation and compliance with the defined ground vibration limits for each cavity. The map is applied at the mine for every blast and when there is a charge constraint, the map helps to define the areas with different charging profiles in the field contributing to higher charging productivity.

Jan 21, 2025

By Joseph A. Meyers

NYC has always been a high-profile target for both foreign and domestic terrorists. Explosives have always been the go-to tool for terrorists to bring about serious physical injury, death, and property damage in our society. Today with the anti-police movement gaining traction in the United States and anarchists groups using homemade explosives against law enforcement and municipalities, it is the responsibility of the explosives industry to ensure that every explosive product on a blasting site is secure. We must prevent the theft of these energetic materials used on projects and sold by vendors so they are not used by these terrorists. We have learned many lessons here in NYC which began with the theft of explosives used for blasting projects in NYC to supply the IRA (Irish Republican Army) 50 years ago. The liability is too significant to take short cuts in securing energetic materials. Over the years through cooperation with all agencies and the industry we in NYC have developed certain proven protocol and procedures we would like to share with the industry. An efficient and effective security plan for the logistic movement of explosives, as well as for the blast site is imperative to keeping the good name of the industry from negative repercussions and possible additional bureaucratic oversight of an industry that is highly regulated and still recovering from the pandemic. Communication, security assessments and transparency with all stakeholders and the Authority Having Jurisdiction (AHJ) will greatly improve the overall security for the blasting project. This SOP (standard operating procedure) will allow the AHJ to become a proactive partner in the security of the blasting project. If the AHJ is not a law enforcement agency, the law enforcement agency specialty unit must be notified and included in all phases of the project. The security for a blasting project with AHJ and law enforcement input starts at the inception of the project when the memorandum of understanding (MOU) is obtained, and involves the AHJ through all steps of the approval process. This includes threat assessments on new and existing structures. SME’s (Subject Matter Experts) must be present at all stages. The blasting industry and regulators must work collaboratively to improve safety, security, and create a dialogue with law enforcement and the AHJ. Relationships are built through trust, teamwork, transparency, and communication and greatly improve the safety of our great country.

Jan 21, 2025

By David Porter, Nathan Rouse

The implementation of presplit blasting has been widely utilized in open pit and underground tunneling. This case study works through the iterative process of developing a heading drill and blast design to control overbreak and limit backbreak in cut and fill headings. The initial design was based on rule of thumb parameters, and the design was then modified for the field conditions based on results. Throughout the design process the drill profile, explosive charge, and timing were modified to yield the best profile compared to design. Data collection during the design process was extensive to best understand the effect of modifying parameters, and gauge performance of design changes. Input from the miners as well as engineers was considered to allow for the best possible adaptation of the design change from existing practices. During the process resistance to change was realized and accounted for to understand the issues that the miners were facing and how to best address them while ensuring high quality blasting. Workforce buy- in was addressed by illustrating the long term benefits of higher quality blasting and the tradeoff of with a slightly more in depth drill and loading cycle.

Feb 6, 2023

By VIVEK KUMAR HIMANSHU, Murari Prasad Roy, Kaushik Dey, Rakesh Kumar Singh, Ashish Kumar Vishwakarma

Sublevel stoping is commonly adopted method in underground hard rock mining. Proper planning and its execution is the key requirement for stope extraction using this method. The stope extraction has been a challenging task since decades. The major reason being the unavailability of free faces as compared to open cast bench blasting. The geological and geotechnical parameters changes gradually even within the stope itself. So the blast design parameters should be planned according to the scenario of upcoming ring. Blast design parameters like burden, toe spacing, inclination of blast holes, diameter of blast holes, charge density of explosive etc plays an immense role in rock damage. For the proper breakage of rock, the movement of burden is prime objective. To study this, explicit dynamic based modeller of M/s Ansys was used. The burden values were varied from 20-65 times diameter to assess optimum burden value during the study. The models were simulated for the rock having 35 MPa uniaxial compressive strength and 102 mm blast hole diameter. Altogether three holes were blasted having hole depth 14-14.5m. The blast design parameters and respective blast induced ground vibration has been measured at the experimental site. Core sample of the rock of experimental site has been used for the evaluation of geotechnical parameters. These geotechnical parameters were inserted into the simulation model. The volume of rock excavated along free face has been calculated in each model. It has been found that the burden value can varies from 35-40 times blast hole diameter (3.6-4.1m) to achieve greater volume of rock along the free face for 102 mm blast hole diameter and rock of 35 MPa uniaxial compressive strength.

Feb 6, 2023

By Joseph A. Meyers

Explosives techniques and technology are constantly evolving and improving, yet basic communication and business skills are not being used regularly. Many potential blasting projects never occur due to simplistic, basic factors, such as a lack of communication. Articulate communication is the key component in the blast approval process, which has changed remarkably from how business was conducted fifty years ago. Imperative to the approval process is communication outlining the safety and benefits of the blasting project.

Feb 1, 2020

By Ron Ketterling

We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes

Feb 1, 2020

By Tristan Worsey, Nathan Rouse

The Florida legislature allocated funding for the Florida State Fire Marshal (FSFM) to review the applicability of the United States Bureau of Mines (USBM) Report of Investigations (RI) 8507 blast vibration limits with respect to Florida and its soils. The study also discusses whether the current blasting vibration limits set by statute are still appropriate, including a review of measured vibration amplitudes and frequencies, structure responses, and theoretical analyses of material strength and strains

Jan 1, 2019

By Kyle Wagner, William Joa, Colter Angell, Catherine Johnson, Marty Langenderfer, David Doucet

The goal of any business is to seek the maximum profitability for the organization through optimization the use of resources, processes and the application of new technologies. An analysis of various case studies demonstrate that blasting can have positive impacts on the crushing and milling processes resulting in increased profitability for the mining industry (Grundstrom, Kanchibotla, Jankovich & Thornton, 2001). This paper describes the case study of two copper mines in Peru producing Cu-Mo and Cu-Au concentrates, which together with their strategic partner, have implemented a project focused on the improvement of rock fragmentation. The project was based on techniques of pattern size reduction, the use of high energy explosives and the technology of electronic initiation. Combined, these techniques were shown to have significantly impacted the efficiency of downstream processes.

Jan 1, 2019

By S. Kevin McNeil, William Joa, Catherine Johnson, S. Omar Garcia

The geometry of an explosive is known to have a fundamental effect on the resulting shock wave propagation. Typically researchers use a spherical or hemispherical geometry in order to simplify the shock wave so that resultant overpressure and impulse are uniform in all directions. The goal of this research is to understand the overpressure characteristics from a sheet explosive, a geometry often utilized for breeching in the military. In training alone, soldiers can be exposed to several tests per day, which may be contributing to the prevalence of blast induced mild traumatic brain injuries. Using PCB pressure transducers and high speed video, it was found that as the angle departed from normal (perpendicular) to the face of the sheet explosive, the over pressure decreased significantly. When in line with the plane, a decrease of over pressure by as much as 20% was observed. Time of arrival was roughly 20% faster directly in front of the charge with a pressure amplification of 46% relative to a spherical baseline charge of the same mass. This testing may reveal a more complete relationship between the pressure and angle from the explosive that could have applications for military and law enforcement with respect to best practices on blaster location for reduced over pressure exposure.

Jan 1, 2019

By Tristan Worsey, Nathan Rouse

Florida legislature allocated funding for the Florida State Fire Marshal to review the applicability of the United States Bureau of Mines (USBM) Report of Investigations (RI) 8507 blast vibration limits with respect to Florida and its soils. The study also discusses whether the current blasting vibration limits set by statute are still appropriate, including a review of measured vibration amplitudes and frequencies, structure responses, and theoretical analyses of material strength and strains.

Jan 1, 2019

By John Babcock, Bryan C. Smith

In a partnership between Luck Stone Corporation and Loudoun Water, a 42” (1.067m) steel pipeline was constructed along the perimeter of an extensive permitted reserve of diabase rock Luck Stone was about to begin mining. Loudoun Water provides drinking water and wastewater services to over 75,000 households in Loudoun County, Virginia. In discussions to establish the 30-foot (9.1 meter) easement for Loudoun Water within the permitted reserve of diabase rock, Luck Stone and Loudoun Water agreed on the following basic conditions: • Luck Stone could execute production blasting as close to the easement as physical conditions of overburden depth permits. We estimated the minimum distance to be about 75-feet (22.86 meters) from the centerline of the pipe. • Loudoun Water would install strain gauges on the pipe every 500-feet (152.4 m) along the entire length of the future reserve area. This resulted in the installation of 18 strain gauges. • Luck Stone would contract a third-party vibration monitoring company, agreed to by Loudoun Water, to monitor the strain gauges and provide seismograph reading at appropriate locations along the pipe as mining progresses. All information would be provided to Loudoun Water. • Luck Stone’s blasting will be conducted in a manner that ensures the recommended strains are not exceeded.

Jan 1, 2019

By Phil Jones, Ben Johnson

During a period of six months in FY2018, a series of trials were conducted to compare drilling accuracy using two different methodologies and the subsequent impact this had on ore dilution. Testing was conducted at Cracow underground gold mine in Queensland, Australia. The drill rig’s existing alignment process was compared to a new technology system with the following observations:

Jan 1, 2019

By Frank Hirthammer

Productivity, customer relations, and effectiveness of work depend to an ever-increasing extent on a functioning logistics system tailored to the needs of the user. Of course, it is not possible to cover and explain all aspects of the logistical requirements of even a small part of an industry, in a single article. The article speaks specifically about the particularities and differences in the logistical requirements in the explosives sector. Starting with questions of safety, handling and quality up to the legal basis, there are special requirements regarding the logistics in the explosives sector. The results of innovative logistics solutions are presented using three examples from daily work practice.

Jan 1, 2019

By Sushil Bhandari, Amit Bhandari

Blast optimization in open-pit operations is a task that often remains at a theoretical stage. Indeed, when it comes to operational blast design and onsite implementation, time restrictions and field conditions make it difficult to execute a planned pattern accurately and optimization according to local conditions is even more difficult. For example, adjusting a drill pattern to a complex face geometry is not something that can be easily undertaken on site. Blasters and engineers will do their best trying to distribute boreholes over the bench and even then, it can take them hours to achieve an acceptable layout. Similar situations occur with delay sequences, when trying to adjust them to address selectivity or vibration issues. For these reasons, operational blast design will often remain at a very basic level and the required adjustments are laid aside due to the difficulty of implementing them on site.

Jan 1, 2019

By Braden Lusk, Tristan Worsey, Nathan Rouse, Kyle Hall

Loading explosives up hole has challenges that are typically not seen in down hole explosive loading. Most explosives applications are not up hole. Lack of experience and technology can cause significant problems when loading explosives up hole. When results aren’t achieved, the blame is commonly put on the design when the true problems are unknown. Not knowing the cause of the problem causes drill and blast designs to be over engineered and very costly with little success. Being able to know and record key data is crucial to actually solving the problem. This paper goes over blast instrumentation that can be used to trouble shoot drill and blast problems in up hole explosives loading in underground mines. The tools and procedures used to trouble shoot include velocity of detonation recorder, borehole tracking, seismographs, and borehole camera. Each item will be discussed in detail with a case study to show the usefulness of the instrumentation. The operation discussed in the case study had issues pulling raises and had hang ups in the stope shots. These problems caused production slowdowns and costly remediation blasting that was not very successful. The case study is an underground gold mine that used modified sub-level caving with backfill as the mining method.

Jan 1, 2018

By Jena Moshen

Underground Bulk Systems (UBS) technology has gained widespread application in tunneling and underground mining owing to its safety, reliability, increased Velocity of Detonation (VOD) and excellent results. However, its application in perimeter blasting is still limited and researchers are looking at ways of harnessing this technology for perimeter control. This simplifies the charging process by using one cost efficient product for charging both the perimeter and grid holes. This paper presents a case study on the application of underground bulk emulsion explosives for perimeter control blasting in underground room and pillar platinum mines. In order to achieve the required coupling ratios in the perimeter holes, the emulsion is loaded into specially formulated smaller diameter polyethylene (poly) pipes. The effectiveness of this method was evaluated using information obtained during routine blast audits and data supplied by the mines on half cast factors, over break and under break as well as analysis of data from Ground Penetrating Radar (GPR) Scans over a period of four years. This method of perimeter control, has given the platinum miners in Zimbabwe a competitive edge in cost effective perimeter charging and blasting by simplifying the previously costly deployment of traditional barrels and other decoupled cartridges. The method has been adopted by all the platinum mines in Zimbabwe as it has proven to be a cost effective alternative of controlling the perimeter walls, along with other key benefits that relate to safety, productivity and effectiveness.

Jan 1, 2018

By Michael Mann, Kenneth K. Eltschlager

The International Society of Explosives Engineers (ISEE) Standards Committee has recently updated both the Field Practice Guidelines for Blasting Seismographs and the Performance Specifications for Blasting Seismographs. The revisions are the result of public and industry input along with recommendations of the ISEE Blast Vibration and Seismograph Section. The committee is comprised of blasting seismograph manufacturers, users and general interest personnel. On an as needed basis, subject matter experts are enlisted to advise the committee. Three phases of activities are necessary for each revision cycle: request for comment on the existing standard, first draft revision of the standard based on public input, and final draft approval by the ISEE Board of Directors. The ISEE standards revision process will be explained and each standard will be discussed along with the significant revisions from the latest revision cycle.

Jan 1, 2018

By Teele Tuuna, Voglers Eesti OÜ

Blasting operations are a strong and important part in any kind of building and mining industry, a shot-firer profession is one of the oldest professions in the civilized world. It still serves an important and ongoing purpose in the modern economy all over the world. Europe, nowadays, values strongly the mobility of workers, the movement of know-how and labor force between different countries inside Europe. There are no borders for most of the everyday professions.

Jan 1, 2018

By Matt Slezak, Tristan Worsey, Nathan Rouse, Kyle Hall

As everyone knows, blasters are required to file blast reports of every blast for regulatory purposes. To this day, the authors see many handwritten blast reports. Handwritten blast reports are notorious for containing errors or omissions. This is not because the blaster intends to misreport information. It is because blasters have many tasks to complete in a day, are sometimes in a rush, and could accidentally miscalculate data, omit items, or record incorrect data. In most cases, blasters do not suffer consequences to these errors because blast reports are seldom reviewed in detail. In some cases, such as when a blasting operation undergoes some sort of litigation process, the reports are reviewed in detail and the blaster is ultimately held responsible. If the reports contain errors, the blaster can be fined, have his/her license revoked, or worse. Electronic blast reporting and centralized data management can help reduce or eliminate the potential for accidental blast reporting errors to occur. This paper presents many ways that electronic blast reporting can reduce or eliminate blast reporting errors, decrease time and extra costs spent reporting, and improve efficiencies in the field and the office.

Jan 1, 2018

By Scott Rosenthal, Logan Connolly

Butte, Montana holds a prestigious place in the history of mining, deemed “The Richest Hill on Earth,” containing a plethora of underground mines. The Orphan Boy/Orphan Girl underground mines, on the western side of Butte, operated from 1895-1956 producing zinc, lead, silver, and manganese. Today, the Orphan Boy mine is part of Montana Tech’s Underground Mine Education Center (UMEC) and the Orphan Girl mine houses the World Museum of Mining. Underground development in the Orphan Boy mine continues to progress as students from Montana Tech receive hands-on underground training; in addition, the UMEC is a multi-disciplinary research facility. Repeated underground blasting occurs in close proximity to old mine workings (wood supports installed circa 1950 or earlier). Research began to determine the impact of underground blasts on nearby pre-existing structures. Using the ISEE Field Practice Guidelines for Blasting Seismographs, one seismograph monitors the predominately-wooden structures to measure their response during each underground blast and one seismograph positioned on the surface to monitor surface structure response to the blast. This paper presents the findings of the research conducted to date for the project. The paper includes analysis of the research data, and conclusions determined from the research. Recommendations for the future work are included as well.

Jan 1, 2018