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By Oliver Finn

Gold dredging has made such rapid strides of late and there is such a widespread interest in this branch of mining that I venture to contribute a detailed account of the way in which a Keystone driller was used by me in California to loosen, by blasting, a very tight gravel deposit, preparatory to dredging. There is a great difference between “cemented gravel” and “tight gravel.” A truly cemented gravel is not a dredging proposition, while the tightest possible gravel, where there is no cement, can be made easy working by the following method of blasting:

Jan 1, 2008

By Frank Hirthammer

"Nowadays, security in the lifecycle of explosives is more important than ever. Terror attacks all over theworld pushed the EU to decree a Commission Directive for the identification and traceability of explosives that set a series of requirements for involved manufacturers, distributors and end-users. The challenge was to find and implement a track and trace system for all concerned European companies byApril 5, 2015. Since then, countries worldwide have followed this example and implemented similarregulations."

Jan 1, 2017

By Chulgi Suk, Hoon Park, Hyonsoo Kim, Hakman Kim, Sangho Cho

Dust emission from blast demolition and other construction activities can be a nuisance; it is widely recognized that fine particles less than 10 µm in equivalent diameter (called PM10) may cause health problems. Mist spray systems, such as rain guns, sprinklers, water/surfactant sprays (or foams) etc., are some of the most effective dust suppression methods. A large amount of research has showed that when water droplets are produced in an equal amount to that of dust particles, the airborne dust is suppressed by the agglomeration of dust and mist particles. A method for generating micro-sized mist from water, achieved by the detonation of explosives in the water tube, was suggested and is called the ‘detonationdriven water bag burst system’. There are many experimentally observed limitations of the explosioninduced water break-up process. The water bag explosion tests were simulated using the AUTODYN software, in order to investigate the aerosolization mechanisms of the detonation-driven water and water break-up process into micron-sized droplets. As a result of the numerical analyses, the diffusion direction of water when detonating in the central interior part of water tube was radioactive and significantly stronger than when detonating in the bottom exterior part; this is due to the compressive flow of the volume change inside of the water tube, which resulted from the blasting wave inside of the tube, as well as the reflected pressure on the ground. Blast tests of full-scaled reinforced concrete columns were conducted to verify the effectiveness of the suggested detonation-driven water bag burst system. The water breakdown and dispersion that occurred while blasting the reinforced concrete columns were observed using a high-speed camera, and dust generation was monitored using four density detectors. The suggested detonation-driven water bag burst system showed that the average dust density decreased by up to 7 mg/m3.

Jan 1, 2016

By Jun Yang, Zongshan Zou, Mei Qu, Jianjun Zuo

For technical renovation of the thermal plant, one frame structure workshop of 50,000 m2 (59,800 yd2) construction area and one reinforcement concrete chimney of 150m (492 ft) height shall be demolished by blasting at same time. The engineering environment of which is complicated and the accommodation space is limited. Therefore, the collapse sequence, direction, scope of the dismantled building must be accurately controlled to ensure the safe operation of the adjacent generator unit and transformer station. By taking technical measures of theoretical analysis and numerical simulation etc., as well as research on structures collapse method and detailed delay interval, it puts forward the technology of bidirectional folded collapse of the workshop and it uniquely adopts the initiation system that combined with “half-second delay inside drilling” and “millisecond delay outside drilling”. Additionally, by using of the integrated vibration reduction technology in combination of the blasting ruins, buffer ditch and damping ditch, it has safely accomplished the demolition blasting work in high efficiency. Besides the demolition blasting vibration signal is collected and analyzed. The success of the demolition blasting will become valuable reference to other similar works.

Jan 1, 2016

By Steve Dillingham

The origin of the written blasting log or shot report can likely be traced back to the earliest annals of blasting and record keeping. These records were, for the most part, a way of checking inventory, production progress, or billing, and not necessarily designed with the intention of being used as a legal document in a court of law. As our litigious society has evolved to include far reaching regulatory requirements, however, the blasting log has developed to support and aid in the defense of the common blaster from blasting lawsuits by providing a comprehensive written report of his or her actions.

Jan 1, 2002

By Steve Dillingham

PHYSICAL BLAST DATA Pattern Description All measurements related to the description of the physical blast pattern must be made with the mind-set that it has to tell a powerful factual story enabling a future accurate reconstruction of the event. A case has never been lost because too much factual information was available to assist investigators. An accurate physical description of the pattern must be provided based on the blaster’s observations of the pattern actually loaded. The blaster must measure the pattern size, depth, face heights, etc., recording only accurate results. All too often, a blaster records simple pattern sizes and information relayed to him or her from the driller, or from a phone call into the office the night before for powder pre-load inventory purposes. If a pattern was actually measured on the job site by the blaster to be 8.5 x 9.5’, it may, in fact, originally have been ordered at 9’x9’, 8’x9’, or 9’x l0’. In a claim situation, particularly flyrock, recording a “generalization” of what was loaded could result in an interpretation of a blaster’s negligence due to “not knowing or caring” what the actual pattern was, and not loading appropriately for conditions. It is important to remember that other documentation exists such as a drill log from a contract driller or mine records that may provide a different interpretation of the loaded pattern.

Jan 1, 2002

By Steve Dillingham

A blast site incident has just occurred. Tensions are high, and, as the blaster, you’re in charge of the crisis at hand. Your mind is reeling, your thoughts frantic. The main areas of concern for you at the scene are to deal with immediate problems...aid the injured, take a head count, assess the damage, call emergency response, contact company headquarters, calm the neighbors, update your customer, and respond to the press on site. You feel as if all the bases have been covered...but, then again, have they? One of the biggest mistakes blasters and their companies can make is not including their Insurance carrier in the critical on-site accident procedures and emergency call list. Unfortunately, many companies believe that they are immune to the perils that can often, within a matter of minutes, create chaos that only happens to someone else.

Jan 1, 2002

By Jean-Sébastien Lambert, Serge Roberge

"At the end of 2014, Holcim Canada (Demix Aggregates Division) considered the possibility of drillingand blasting a big volume of rock in order to expose a high-quality limestone bench in one of their urbanarea quarries in Laval, Quebec (Canada). The project includes many challenges and has thus been qualified as a high-risk operation."

Jan 1, 2016

By C. McAllister, D. Preece, J. Berendzen

The Multiple Blasthole Fragmentation (MBF) model was developed recently and has been reported in previous papers. The MBF model accepts inputs from the blast design, such as: location and orientation of each blast hole, stemming length, blast hole diameter, multiple decking, bench height, initiation sequence, etc. It models the effect on fragmentation of delay timing with its associated scatter for each blast hole. MBF has a statistical modeling capability for geological random variation of the attenuation of particle velocities. Also simulated is wave reinforcement due to the interaction of simultaneously arriving waves or diminishing cooperative contribution from long delay intervals between charges.

Jan 1, 2016

By Tom Barry, Kameron Ray, Dr. Gavin Yuill

Imerys Talc, Yellowstone Mine in Montana faces significant geotechnical challenges such as poor wall quality and local instabilities. These instabilities are driven primarily by the characteristics of the rock mass, but are aggravated by drilling and blasting operations.

Jan 1, 2016

By S. Klerkx, R Battulwar, J Valencia, J Sattarvand, E Emami, M. Soleymani Shishvan

A new technology for energy distribution optimization, supported by NIOSH.

Feb 1, 2020

By Rob Farnfield, William Birch, Douglas A. Anderson

In the blasting industry, even to the most safety conscious shotfirer, misfires are a constant source of concern. In the United Kingdom, there are two types of misfire, as classified by the Health & Safety Executive. Type A occurs when testing a shot before firing reveals broken continuity that cannot be rectified. However, due to the fact that a majority of quarries use non-electric initiation [i.e. shock tube] that cannot be tested, this type of misfire is very unusual.

Jan 1, 2016

By Campbell Robertson

The evolution of electronic detonators in commercial mining, construction and demolition has been a transformative journey, characterized by technological innovation, enhanced safety measures and improved precision. This abstract explores the historical progression and key advancements in electronic detonator technology highlighting its impact on the industry as well as the challenges in deploying these types of technologies. Electronic detonators represent a significant departure from traditional initiation systems offering precise timing capabilities and improved reliability and safety. The early development of electronic detonators can be traced back to the late 20th century with the introduction of basic electronic initiation systems. These early iterations provided a glimpse into the potential for greater control and accuracy in blasting operations. As technology progressed, electronic detonators underwent significant refinement incorporating advanced features such as programmable delay times, multiple firing sequences, expanded blast size and enhanced communication capabilities. These advancements revolutionized the way explosives are deployed in mining and demolition applications enabling engineers to tailor blasts to specific geological or environmental conditions and structural requirements. One of the most notable developments in electronic detonator technology is the integration of microprocessor-based control systems. These systems allow for precise calibration of detonation parameters, including timing, sequence, and energy distribution. By leveraging microprocessor technology electronic detonators have become increasingly sophisticated offering unprecedented levels of precision and safety in blasting operations. The advent of wireless communication technologies has further augmented the capabilities of electronic detonators. Wireless detonation systems enable remote initiation and real-time monitoring of blasting operations enhancing safety by reducing the need for personnel in hazardous environments. The evolution of electronic detonators has also been driven by a growing emphasis on sustainability and environmental stewardship. Modern electronic detonation systems are designed, amongst other objectives, to minimize environmental impact, achieve optimal fragmentation outcomes and reduced misfire rates during blasting. These advancements not only improve safety for workers and surrounding communities but also contribute to a more sustainable approach to mining and/or demolition activities. In conclusion, the evolution of electronic detonators has transformed the landscape of commercial mining and demolition offering unprecedented levels of data integration, precision, safety, and environmental responsibility. As technology continues to advance, electronic detonators are poised to play an even greater role in shaping the future of blasting and explosives engineering.

Jan 21, 2025

By David La Rosa, Matthew Craft, Lee Julian

Rules of thumb are ubiquitous in blasting. Typically presented as ratios, they assist with the initial assumptions of blast design and provide guidance for best practice. Examples include the blast hole diameter as a function of bench height, and stemming length as a function of hole diameter. The most common rules of thumb were developed in mid-20th century and it is important for a blaster to know if the rules of thumb are still reliable.

Feb 6, 2023

By Neal Lee, Braden T. Lusk, Brendan McCray

Determining the minimum amount of inert material that can be used between explosive columns is a complex problem. Using too little inert material can result in detonator/primer failure, either by sympathetic detonation of or failure to fire of the subsequent explosive column(s). Propagation type failure results when inert material length between charges is small enough that the subsequent (delayed) deck fires more or less instantly. In this situation, the primer, detonator, or bulk product is initiated by the shock wave from the earlier firing deck. This type of failure may be un-noticed until the vibration/airblast report is examined.

Jan 1, 2016

By Paul Sainato

Recruiting and retaining students in the explosives industry is becoming increasingly important each year. With no undergraduate degree in explosives engineering currently available in the United States, it is from other industries and degree disciplines we must recruit. The 2014 annual ISEE conference saw the first anonymous online survey distributed to members of SEE student chapters of the International Society of Explosives Engineers. The survey contained questions about future job and career plans, ideal job placement, expectations of salary and current academic degrees. The purpose of the survey was to determine what these students expect or require from a career in the explosives industry, and their current path to pursue this. This information can help steer recruitment activities and job offers for graduating students. The success for both student response rates and interest from the industry has allowed space for a yearly update of this survey. A second survey was distributed in 2015 and included international students. This paper provides the data from a third online survey distributed to all student members of the International Society of Explosives Engineers, globally. Understanding the main incentives for a student to accept a graduate position as an explosives engineer can help us, as an industry; position ourselves to remain competitive in recruiting against other major degree disciplines.

Jan 1, 2016

By Andrew Palangio, Blessing Taiwo

Understanding rock mass structural features is essential for optimizing blast design, highwall control, and evaluating post-blast performance in both surface and underground mining operations. This paper presents a comprehensive methodology utilizing image-based structural mapping to accurately characterize geological discontinuities including joints, faults, and lineations captured from both terrestrial and aerial imagery at varying scales. Key structural parameters such as joint orientation, spacing, and apparent in-situ block size are extracted to understand rock mass classification and enhance blast design inputs with greater geotechnical precision. The study introduces a significant enhancement to the existing discontinuity assessment algorithm by integrating a deep learning-assisted detection process. This improvement enables more accurate, quantitative and consistent identification of pre-existing cracks and surface features across complex bench free faces. The enhanced system facilitates better evaluation of how structural features influence blast fragmentation, energy distribution, and slope stability. A case study from a limestone quarry illustrates the use of a derived comminution factor based on the relationship between joint-controlled pre-blast block sizes and post-blast fragmentation to evaluate blast performance and optimize future design strategies. The results highlight the value of structural analysis in reducing overbreak, minimizing underbreak, and improving fragmentation predictability. This paper emphasizes the importance of integrating structural assessments into the blasting workflow to enable a more data-driven, geotechnically informed, and performance-optimized approach to modern blast design and evaluation.

Jan 26, 2026

By Ery Wardhana, Fathur Rozaq, Jeff Averett, Nella Lubis, Carl Lager, Herry Saputra, Rudolf Sitorus, Relinda Sanistrya, Hormat Sinaga, Andhiko Maharjono

Efficient drill and blast operations are crucial for achieving optimal fragmentation, productivity, safety, and operational efficiency for the mining industry. However, conventional methods face significant challenges, including manual borehole marking and retrieval by survey teams, limited real-time data monitoring, excessive borehole collar deviation affecting blast quality, suboptimal drill productivity impacting person-hours and fuel usage, subjective judgment by drill operators on voids during drilling, and limitations in explosive charging design that do not match rock hardness. Rock hardness determination using lithological data from exploration models is often inaccurate due to the interpolation effect of wide drilling distances and depths, necessitating manual field verification using drill cuttings and historical blasting results. Furthermore, using single-density bulk emulsion throughout blast holes leads to suboptimal results due to varying rock properties. This study introduces an integrated approach that combines smart drilling technology with advanced emulsion technology to enhance drilling and blasting efficiency. The method utilizes smart drilling technology with GPS for precise borehole placement, Measure While Drilling (MWD) loggers, and real-time performance monitoring. Additionally, it integrates a smart Mobile Processing Unit (MPU) featuring a digital system and an automated gassing system (AGS). This setup allows for multiple emulsion densities within a single blast hole, customized to match the hardness index parameters determined from MWD data, addressing the challenges in drilling and blasting operations. The study evaluates the effectiveness of this innovative approach through comprehensive field trials and data analysis. While maintaining the digging rate according to production targets, key metrics such as drilling productivity, drilling accuracy, fuel consumption, powder factor, drilling and blasting cost, and fragmentation size were compared between conventional and new methods. Results showed a 56% increase in drilling accuracy, a 23% increase in penetration rate, a 19.6% increase in drilling productivity, and a 29% reduction in fuel consumption. This new method decreased the powder factor by 5.2%, impacting the drill & blast cost reduction by 2.3%. Moreover, fragmentation size improved by 12.8%, demonstrating the effectiveness of rock hardness-adjustable emulsion density in achieving better blast energy placement. In conclusion, integrating smart drilling and advanced emulsion technology significantly enhances drilling and blasting efficiency. This approach offers substantial cost savings and operational improvements, providing a strong rationale for adopting this innovative method in drilling and blasting activities.

Jan 21, 2025

By Peter Dare-Bryan, Will Hunt, Lee Julian

It is well-known that blasting has an economic effect on grade control activities. However, until recently, methods did not exist for measuring the grade control value change caused by the blast. Rules of thumb were the best method to minimize ore loss and dilution, as simulation has been traditionally constrained by time and computer power. Even with these rules followed, an extensive study performed on over 150 blasts showed that the value change caused by the blasts followed a normal distribution – some blasts created value, and some blasts destroyed value. The question naturally asked was “How can we ensure the blast designs are optimized to create value?” Recent advancements in computer power have enabled real-time blasting simulations that create post-blast grade control models before the blast is fired. Understanding what will happen before it happens allows blasters and grade control personnel to iterate designs, searching for the highest value achievable.

Feb 6, 2023

By Richard Givens, Thomas Baginski

Technological advancements in warhead designs and implementations have driven the development of arrayed initiation networks of highly accurate, highly reliable, and extremely safe detonators. Recent development efforts have produced advanced Exploding Foil Initiator (EFI) based systems that have been adapted for civilian use in commercial blasting applications.1,2,3,4,5 This novel, high technology system promises multiple improvements and advantages over the manufacturing, transportation, tracking, storage, inventory and field operation of current detonator systems. Ultimately the insertion of this technology would result in fielding a Non-Energetics Based Detonator (NEBD). Insertion of complementary technologies into the detonator’s supporting systems would greatly advance current detonator hardware/software.

Jan 1, 2011