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By Matias Suarez, Diego Zenteno

It is known that the introduction of electronic timing in the sequencing of blasting has changed the vision and way in which mining is developed. It is possible to deal with more complex and sophisticated drilling designs, without compromising productivity or safety. It has been shown in various studies, that a correct timing of the blasting provides an improvement in the improvement of the processes downstream, due to a decrease in the resistance of the resulting fragments coming from the interaction of the waves generated in the detonation of explosive loads. On the other hand, it has also been shown that variations in the composition of a same type of explosive, has a significant influence over the resistance of the blasted material, also the energy associated to break it, affecting directly its degree of fragmentation. This paper is aimed to display the new advancements of blasting engineering done in different mining sites throughout the country, associated to electronic sequencing, energy of the explosive and its impact on the fragmented rock. This document explains how to define and implement selective sequencing in the blasting in order to promote the propagation of cracks, therefore impacting positively the productivity through the use of the LaGrange diagram. The LaGrange diagram is a very convenient and illustrative method to present the dynamic behavior associated with wave and crack propagation (Rossmanith. H, 2002). This study focused on the methodology of the formation and measurement of seismic pulses, through the rock massif. For this purpose, seismic pulses were acquired in the field and then, the different dynamic phases of the wave were molded mathematically, with the purpose of favoring the coupling between them.

By Ayman Tawadrous, Hendrik Botha, Simon St J Tose

The early miners and their mules always had the challenge of transporting unstable dynamite underground. The modern pumpable explosives, whilst far safer, still present a major logistics challenge for the mobile charging units (MCU). The challenge today is the efficient explosive delivery into declines, ramps, and vertical shafts, often requiring the MCUs to travel excess distances up and down to surface to re-load. Alternatively, the management of cassettes or ISO containers is utilized to deliver the pumpable base emulsion to the MCUs at the working face. Additionally, local laws and regulations regarding shaft clearance further compound the task and result in pausing other operations in the shaft or decline or ramp until the completion of the explosive transport. This paper examines the research & development challenges of dropping base emulsion down a vertical pipe to depths in excess of 1000 m (3280 ft.), either to an underground storage or directly into the MCU, depending on the depth. The boreholes (with pipes) are drilled in close proximity to the underground work areas. The paper also discusses the rheology of the emulsion within these vertical pipes as well as the economic benefits of such an innovative system. The learnings gained from this work, along with examples demonstrating the significant reduction in MCU travel and the safety benefits, are presented for the industry to consider moving forward.

Jan 21, 2025

By Norman Paley, John Kells

The climate and location of the Red Dog Mine present several challenges to blasting operations. The mine is located north of 68º latitude, in an area of continuous permafrost. Ground temperatures are below freezing year-round and air temperatures range from -40 to 70°F (-40 to 20°C). Because there is no overland access to the mine, the entire year’s supply of bulk explosives, approximately 7,000,000lbs (3,175,000kg) is shipped in by barge during the 100 day shipping season when the port is ice-free. The first week in July is the earliest that new product arrives at the port. Emulsion usage is maximized from mid April through October when surface water fills the blastholes during drilling. This necessitates that a considerable portion of the bulk explosives are stored for 10 months or more before usage. The emulsion is routinely pumped from the ISO containers at temperatures of 20ºF (-7°C). The mine engineers conducted a testing program during the 2001-2 blasting season to identify the bulk explosives best suited for the conditions at the mine. A secondary goal was to decrease the usage of sensitized emulsion, as this is the most difficult portion of the explosives order to ship. To ensure repeatability when transferring the results to the day-to-day blasting operation, the majority of the testing was incorporated into normal blasting operations in the field. The mining methods used at Red Dog Mine make direct fragmentation analysis impractical and performance testing in the field relied primarily on VOD measurements. The products were also tested for their ability to be pumped in cold temperatures.

Jan 1, 2004

By Jorge Cárdenas, Luis Huaroc, Máximo Cari, Nestor Delgado

In Peru, after four years of pandemic, some mining companies have chosen to install integrated operating centers in central offices where through network technology and video surveillance it allows them to carry out their activities remotely, this has become a disruptive strategy to promote a safer and smarter mining industry. Our fundamental value is to improve the quality of life, safety and well being of our collaborators, that is why we have created the remote blasting engineering control center " Core" that allows us to humanize mining. Core is an integration of experience, security, technology, quality of life and artificial intelligence; it has media technology connected directly to the mining operation, specialist engineers and technical assistants in team they seek to create optimal proposals of drilling and blasting designs remotely that generate added value to customers. In the planning process the team suggests drilling meshes, in the loading process there are optimized, digitized designs and efficiency in the factory trucks finally in the safety process allows us to identify inadequate pipes within the blasting project, deviation of procedures, remote inspections, identify operating conditions to prevent future risks that may arise in the blasting process. The remote communication systems allow you to monitor mining operations remotely to identify and alert any operational or security deviation that was not identified by the personnel present in the operation, as well as to store images in case investigations are required. The results obtained have allowed us to reduce the exposure of personnel to any risk of the mining operation, to optimize times in the activities of our engineers who are in the mining operations since there is the permanent support of centralized specialists to face every challenge that arises in the operation, for the engineers who are in the offices of Core can be very close to the family and do not lose it, and for our customers it is to meet their needs with engineers specialists in the drilling and blasting process, as well as in safety to be able to proactively cope with any deviation that arises.

Jan 21, 2025

By Walter Valery, Sarma Kanchibotla

Due to the global financial crisis, the world economy has turned upside down and most major economies in the world are facing severe recession for the past one and half year. During this period most commodity prices have tumbled by more than half from their peaks and such a sudden and severe economic downturn is not seen since the great depression. This sudden drop in commodity prices and lack of credit made many mining operations unviable and even those mines that are marginally viable at this point are operating under severe cost pressures and capital expenditure restrictions.

Jan 1, 2010

By Joshua Micah Hoffman

While it is easy to state that meaningful involvement of the community can play a critical role for a successful blasting operation, following through with this involvement is not an easy task. Structured Public Involvement (SPI) is a developed protocol for involving communities in project planning decisions and could be readily applied to the blasting industry. SPI was developed for the purpose of collecting quality public input about public transportation projects. The purpose of SPI is to bring about stakeholder satisfaction with potential projects by allowing controlled input from the stakeholders. It was designed and intended for democratic societies that have come to expect a voice in public projects. While blasting operations are not always in the domain of public projects, the fundamental process outlined by SPI can be useful for collecting feedback from the immediate public around blasting operations.

Jan 1, 2014

By Michael Weaver, Dale L. Ramsey

The Pinkerton Tunnel open cut project is part of the National Gateway Clearance Initiative improvement project to achieve a minimum of 21 feet of vertical clearance along CSX Transportation rail corridor so that double-stacked intermodal railcars can be transported between mid-Atlantic states and their ports to midwest markets in the U.S. This project involved drilling and blasting of 1.2 million bank cubic yards of rock over a 14 month period while maintaining rail traffic of two passenger and 38 freight trains daily. See story and photos, page 6.

Jan 1, 2015

By Paulo Couceiro, Juan Navarro

The impact of rock blasting fragmentation and heave on digging performance in open-pit mining operations is usually the first true indicator of blasting outcomes. Within the typical excavation cycle, the bucket loading time or instantaneous digging rate are the ones that present the strongest correlation with rock fragmentation size distribution, swelling, and shape of the muckpile, a part of rock mass hardness, equipment size, power, and others. As the efficiency of unit operations becomes increasingly important for long-term mining strategies, cost-effective approaches are needed to increase mine productivity. In this line, the performance of downstream operations, such as digging, hauling, and comminution, may be affected by the energy input in blasting. This requires a better understanding of the explosive’s energy role in such unit operations in order to drive consistent improvements. Therefore, this paper examines the impact of the explosive’s energy distribution on shovel diggability from production shots carried out with different explosives in an open pit gold mine, with the aim of modelling the interface between blasting and excavation.

Jan 21, 2025

By S. Gajardo, E. Valdés Guerra

Together with Sociedad Punta del Cobre S.A. (Pucobre) and Orica, we are carrying out a study of alternatives for methodology of excavation in Slot Up Raises from actually built with Blind Hole (BH) to drilling and blasting (DB) methodology. The study is part of the permanent search for innovation, the use of technology and the reduction of mine operation costs. This application aims to optimize the Sub Level Stoping method, which has historically been exploited at Pucobre. Using a new variant of the method “Open Stoping”, through the initial development of ascending blind raises using a pilot drilling of a bore hole, with the objective of eliminating the upper level in order to excavate the free face opening. This industrial test aims to replace the mechanized BH Up Raise of 1.5m (4.9 ft.) in diameter and 30m (98.4 ft.) high, with a Up Slot Raise considering two separate blasting events, using different technological enablers, as detailed below: accuracy drilling with relief holes of 254mm (10 in.) diameter, high viscosity bulk emulsion, wireless initiation system and high-strength injectable bulk resin. Considering the importance of the success of this application, a DB diagram was defined to allow the opening of the up raise in two blasting events, separated by intermediate stemming deck located at the same level at a height of 15m (49.2 ft.) from the collar, using high-strength injectable resin. The first blasting event considers the first section from the collar to the first 15m (49.2 ft.), using wired electronic initiation that is detonated on the first day. A second event blasts the section from 16.5 to 30m (54.1 to 98.4 ft.), using a wireless initiation system, as, it has no physical connection, is blasted on the second day after the extraction of the material resulting from the first event. For greater precision, the design of the explosive charge configuration and initiation sequence is made, adjusted to the measurements of trajectory deviations of the actual ground drilling and is also considered for the control of the explosive charge configuration with high viscosity bulk emulsion. This application improves the profitability of the mining business by generating savings through the change of Blind Hole methodology, estimating a savings of more than 75% per Up Slot Raise

Jan 1, 2024

By Braden Lusk

Vibrations as a result of blasting practices in mining engineering are a complex phenomenon controlled by many variables. Mine blast vibration modeling and prediction is becoming more important as a consequence of the general negative perception of mining activity by the public. Many communities (all over the world) close to mining activity often complain about airblast and vibrations produced from blasting activity. It is important for the mining industry to have tools and understandable methodologies to model and predict blast vibration. These tools can then be used to control vibration at neighboring structures.

Jan 1, 2013

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 Jennifer Williams, Donald J. Berger

Originally built between 1913 and 1916, the Ashton Dam & Hydroelectric Facility has experienced various seepage and piping incidents since completion. Ashton Dam is located within 15 miles (24 km) of the historical Teton Dam failure site and about 2.3 miles (3.7 km) west of Ashton, Idaho. Numerous repairs conducted over the years ranged from filling sinkholes on the crest of the dam to placement of rockfill on the upstream slope to improve seismic stability. In addition, the existing low level outlet works was grouted full and abandoned in 1991 due to significant vibrations induced on the dam during its operation.

Jan 1, 2014

By R. Farnfield, W. Birch

Arguably, some of the most restrictive statutory blast vibration requirements attached to mineral extraction operations can be found in the United Kingdom. Such limitations are, as a rule for the UK, stipulated together with a required statistical confidence that has to be observed in the blast design process in order to ensure total planning compliance. A key element in this procedure is the effect imparted by vibration data scatter from previous blasts as this becomes reflected in the site’s operational standard error statistic and in turn directly influences the maximum instantaneous charge weights that can be justifiably employed. The greater the scatter, the lower the compliant charge weights become.

Jan 1, 2006

By Andre Koekemoer, Gys Landman

At the moment, electronic initiation is migrating from a position of a specialist niche to that of a more widely applied technology. Ease of use and deployment rate are becoming aspects of greater concern for end users.

Jan 1, 2011

By John Watson, Jay Rodgers

The world of blasting and explosive use continues to evolve into one which relies heavily on measurement, quantification, process control, and information feedback as a means of contributing to operational improvements. More than ever good blast performance, once thought to be a result of someone’s “artistic ability”, is giving way to “hard science” and measurement techniques. Variability in product performance and process control is becoming less tolerable with increasing environmental issues, regulatory pressure and public awareness.

Jan 1, 1998

By Raymond H. Green, Mitchell W. Green

The authors examined the application of precise millisecond delay electric blasting at a well-known Vermont quarry. The paper explains how the use of a new high-accuracy electric delay detonator has improved fragmentation, raised productivity 10%, simplified blast design, and increased the ability to predict results from blasting.

Jan 1, 1986

By L. Chaves

In rock blasting, due to numerous factors, both controllable and uncontrollable, the execution rarely meets the planning. The powder factor is an important KPI for blasting since it represents the amount of explosive used to fragment the rock, therefore it depends on the rock mass characteristics and may be influenced by factors such as weathering and drilling quality. The blasts at the Serra Sul mine, S11D project, are usually big blasts and the high productivity is a challenge for maintaining the quality of the whole drill and blast process. It is important to know the contributions of each of the most common influencing factors of the powder factor to direct the efforts to the improvement of the process. A buildup model is presented to evaluate the contributions of five influencing factors to evaluate the planed x executed powder factor. The factors considered in the model are the average hole depth, the amount of hole/blasted volume, the stemming and decking length, the linear charge weight, and the density of the explosive used. The build-up may be applied for both individual blasts and for overall view of the blasts in a period. A case study is presented with the application of the model for the monthly powder factor analysis at Serra Sul mine has contributed to direct efforts to enhance drilling quality and preservation of the drilled holes.

Jan 1, 2024

By M. Gonçalves Peixoto da Silva, E. Rodrigo Carvalho Souza Siqueira

Mining in narrow veins is commonly applied for precious metals, generally carried out to extract gold in underground mines, due to the ore occurrence on narrow veins, mainly up to 2-meter large. The current work presents the implementation of the methodology in a zinc mine located in the state of Minas Gerais in Brazil. The Vazante Mine through the years has always carried out mining on stopes with a thickness larger than 3,5 meters, but nowadays due to the need to reduce the waste planned in its blocks, as well as increase the useful life of mine, mining has been implemented in blocks that are less than two meters. Given this, the challenge is to be able to carry out blasts that does not exceed the operational dilution required and does not generate an impact on recovery, as working with extremely heterogeneous stopes. This study seeks to correlate the main characteristics of stopes and its relationship with the results obtained in the execution of those blasts. Also, it proposes an analysis between the empirical data, and existing theoretical references, creating ideal mining parameters, such as minimum thickness, maximum height, and optimum timing in the blast plan. One of the main challenges for carrying out this mining method is the control of operational dilution, generally pointed out as the biggest difficulty for companies that adopt this methodology, due to the thickness of those stopes, any displacement can make it unfeasible, thus the technical level on carrying out the drilling and loading of these blocks must be impeccable, an understanding of the structural geology of the site is also essential for dilution control. The outcome will be a set of ideal parameters and mining methodology to guarantee the success in execution of these blocks, thus bringing a financial benefit to the company.

Jan 21, 2025

By Harry Verakis, Thomas Lobb

In the past decade, approximately 5 billion pounds of explosives were used annually in the United States. Most of this quantity of explosives was used by the mining industry and coal mining was the dominant application for explosives. Considering the large amount of explosives used, the accident safety record for the mining industry has improved significantly over the past two decades. Blasting accidents are usually a small percentage of the total number of mining accidents. However, blasting accidents continue to occur and the severity of these accidents is disproportionately high with respect to other types of mining accidents. This paper is a summary and an update of the surface mine blasting accident investigations and studies conducted previously by the Mine Safety and Health Administration (MSHA) and the former U.S. Bureau of Mines.

Jan 1, 2001

By A T. Spathis

The 11th International Symposium on Rock Fragmentation by Blasting (FRAGBLAST 11) was held in Sydney, Australia, between 24-26 August, 2015. The 93 papers, including six keynote presentations, covered exciting and practical topics in 20 sessions within 12 themes. Just fewer than 300 delegates from 27 countries attended. Four workshops were conducted on the weekend prior to the symposium, with three field visits after the symposium to Sydney region quarries, the Hunter Valley coal mining region, and the Kalgoorlie gold mining region. Delegates had the opportunity to visit the exhibition areas that showcased the latest products, software, hardware and systems in blasting technology. The keynote addresses were held in plenary sessions and set the tone for the parallel sessions that followed. They spanned the dynamics of the mining industry, the detonics of explosives, the interaction of stress waves and fracture mechanics in fragmentation, wall control blasting, and the importance of education and engineering for full process optimisation.

Jan 1, 2015