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By Norman Paley, Zachary Pickett

The Red Dog Mine is a high-grade zinc-lead mine located in northwest Alaska which began operations in November 1989. In June 2014 the upper half of a charge in a trim shot in the Aqqaluk pit deflagrated. No other holes in the area were observed to react and the remainder of the pattern was shot without incident. This was the only known case of a deflagration in the 25 years of operations. As part of the investigation into the cause of this incident rock samples were obtained from the area of this hole and from other areas in this pit. The samples were assayed and tested for reactivity using the Reactive Ground Catalyzed Adiabatic test. Approximately half of the samples were found to be reactive with standard blasting agents. Unexpectedly, some of these were found to be reactive with blasting agents doped with urea to act as an inhibiter. Relationships between element grades and reactivity and between Specific Heating Capacity and reactivity were developed; however, the small sample size led to these models having an unrealistically large number of geological model blocks tagged as reactive. A program to better understand the behavior by testing more samples was initiated. Drill core was selected based on the predicted level of reactivity using the aforementioned relationships. The samples covered a greater range of grades and lithologies and included rock from the soon to be developed Qanaiyaq pit. The samples were dry pulverized then split for elemental assay, Reactive Ground Catalyzed Adiabatic testing, Specific Heating Capacity (SHC) determination, and X-ray Diffraction (XRD) mineralogical analysis. From this data, a Red Dog Mine specific assay based classification for separating reactive from non-reactive ground was developed. Furthermore, it was possible to divide the reactive ground into two subgroups: i) rock which reacts with ANFO-emulsion blends even when manufactured specifically with a reactivity suppression agent like urea and ii) rock which reacts with ordinary ANFO-emulsion blends only when a reactivity suppression agent like urea is absent.

By Andrea Brickey, Ethan Marcoux

The South Dakota School of Mines and Technology (SD Mines), located in Rapid City, South Dakota, is one of only a few universities in the United States that offer a Bachelor of Science in Mining Engineering. The Department of Mining Engineering and Management (MEM) at SD Mines teaches courses that introduce students to concepts related to mining, including a course covering explosives engineering. Students are taught the basics of explosives theory and application in the mining and construction industry through a series of lectures and assignments. With limited field experience, many students find some topics difficult; these include: flyrock, ground vibration, timing, and others. Some US mining schools have an experimental mine in which they can simulate field conditions and conduct hands-on training, but not all universities have such facilities. For those without, teaching certain concepts can be more challenging in a pure classroom environment. To counteract the lack of an experimental mine, the mining department at SD Mines implemented Paradigm (Version 18.4.4984.0; McKenzie, 2017) a computerbased blast modeling software to improve the learning environment.

Jan 1, 2019

By Robert B. Hopler

The Hercudet ? Nonelectric Delay Blasting Cap System has undergone significant changes since the last paper on the subject was presented at the 1978 S.E.E. Conference. The changes have been made to improve reliability of the blasting machine at low temperatures, and to improve efficiency and economy in usage in surface mining. The paper includes examples of the blast design process, details of use of the new in-hole connected cap, and delay patterns which have found use in quarrying and coal stripping.

Jan 1, 1980

By M. Khaled, K. Abdel Rahman, M. Khattab

Helwan limestone quarry is located at a distance of 35 km (21.7 miles) to the south of Cairo downtown. Drilling and blasting operations are used to extract the limestone for the Helwan Cement Company (HCC). In 1980’s a new urban community was constructed adjacent to the quarry. This situation led to shifting of the old quarry 5.0 km (3.1 miles) to its current location, to avoid causing blasting problems to the new community. Unfortunately, the new quarry is opened in a highly faulted area, with weak zones of brittle materials. The drilling and blasting crew is facing many difficulties due to the geological complexity along these zones. Moreover, the extension of this community towards the new quarry makes the control of ground vibrations is very important.

Jan 1, 2008

By Ricardo Chavex, Adrien Letellier

Flyrock remains one of the most critical issues in open-pit blasting. Despite the significant improvements made with modern surveying methods, the necessity remains to define sensible danger zones around blasting areas. Therefore, many semi-empirical models predict flyrock distances based on trajectory calculations and probabilistic adjustments. However, most are merely based on nominal parameters, even though a considerable amount of precise data is nowadays available thanks to modern measurement techniques using lasers, GPS, drones, and probes. These data provide accurate information about the actual field circumstances of a blast concerning geometry and rock-mass conditions. So how can we use and integrate them into existing flyrock models? The answer to this question can significantly improve the accuracy of flyrock prediction models and enhance safety. This paper will present a method to adapt existing models to actual field data using appropriate software and digital tools during the blast design process. In addition to calculating a more pertinent danger zone perimeter, this method provides an efficient and practical tool that helps prevent flyrock incidents. Indeed, it allows the blast designer and shot firer to be warned if there is a hazardous critical deviation due to local conditions. Moreover, it also enables blasters to communicate better and share the visualization of the blast-specific evacuation zone. The paper will also discuss how this method can be calibrated and how it has been used to analyze some actual flyrock incidents.

Jan 21, 2025

By George Young Mosteller

This paper is summary of the practical solutions developed in the excavation of drilled piers (caissons) at GPCo's Plant Scherer, Juliette, GA. Plant Scherer is a 3,245 Megawatt Fossil Fuel Powerhouse and, when completed, will be one of the largest fossil fuel plants in the Southeast.

Jan 1, 1980

By Tristan Worsey, Nathan Rouse, Daykin Schnell

The authors were retained by a proposed underground metals mine operation to evaluate the potential blast vibration amplitudes that could be generated at surface structures above the proposed mine. Literature reviews of published blasting documentation gave little information, data, or models on surface blast vibrations produced by underground mines. At the client’s request, the authors contacted a number of underground mining operations to evaluate interest in sharing blast vibration data with the authors so that the authors could develop an underground-to-surface blast vibration regression equation. The authors worked with three underground metals mining operations to collect surface blast vibration data produced by heading blasts and stope blasts. The data included blast vibration amplitude values, seismograph records, blast design geometry, charge weights, and detonator delay and sequence designs. The total amount of information was used to produce a regression equation and summary dataset that could be used by the proposed underground mining operation to evaluate blast vibration amplitudes that will be generated on the surface. This work is published and presented so that operations with proposed underground mines or proposed underground mine extensions can use these equations to predict vibration amplitudes on the surface above the mine workings before any blasting occurs.

By Charles L. Greening

MARTIN MARIETTA CEMENT at Martinsburg, West Virginia, has been and presently is engaged in coupling present open pit with old underground workings. Various drilling and blasting techniques have been introduced in an endeavor to achieve optimum results. This paper will relate to three roof shots at Martinsburg, one of which realized a controlled blast of 248,000 tons of material.

Jan 1, 1982

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 Anderson da Cunha Meireles, Pedro Garcia, Ernst Young, Leandro Coelho, Carlos Eduardo Soares Feliciano, Key Fonseca de Lima

Rock blasting is a crucial technique employed in mining construction and quarrying industries to fragment large rocks into smaller, more manageable pieces. However, it often generates ground vibrations that can pose significant challenges. This study explores the application of Conformal Prediction (CP) in the context of rock blasting to develop predictive models that estimate blasting-induced vibrations and quantify the associated uncertainties. Various machine learning models were integrated within the CP framework using MAPIE and CREPES libraries. The results demonstrated the effectiveness of CP in providing statistically reliable prediction intervals, making it particularly useful for applications where the stakes of underestimating uncertainty can be high.

Jan 21, 2025

According to the Directive 93/15/EEC, given on 5th of April 1993, all the commercial explosives placed on the market and transfered in European Union and EFTA countries have to be certified and contain the CE-marking. Before the products can be awarded by the CE-marking they have to fulfil the Essential Safety Requirements (ESR) of Appendix 1 of the Directive. From the beginning of last year the commercial explosives could not have been be sold in Europian Union countries without the CE-marking. The legitimacy of the Directive 93/15/EEC encompasses High Explosives, Detonating Cords, Safety Fuses, Gun Propellants and Detonators. At the moment in Europe, there are seven Notified Bodies (NB) working in the field of commercial explosives. They are in Spain (LOM), Germany (BAM), France (INERES), England (HSL), Netherlands (TNO-PML), Sweden (SP) and in Finland (PvTT). The Swedish SP has qualifications only for the detonators and the Finnish PvTT for High explosives, Detonating cords, Safety Fuses and Gun Propellants, but not for the detonators. The role of the NB is to work as a third independent body between the client and the manufacturer testing, studying and certifying explosives by the commission of the manufacturer. The Notified Bodies are operating independently competing the clients, the explosives manufactures.

Jan 1, 2004

By Gimtong Teowee

SDI has launched the Electronic Detonator Blasting System containing a set of robust serial protocol and hardware exhibiting great ease in field usability and deployment. Programmable delay time with increments of 1 ms up to 10s is possible with excellent timing accuracy. Bus length of up to 2 km containing 1600 EIMs can be employed. A key feature of the SDI Electronic Blasting System has been its high tolerance towards current leakage in the bus line.

Jan 1, 2007

By Gerald R. Coonan

Laboratory research is being conducted to substantiate suggested levels for voluntary standards on human response to transient vibration. The application of those findings to actual field conditions, however, will be limited because they will not include social and psychological factors existent in the real world. It is necessary, therefore, to examine available empirical information on complaints in an attempt to define the influence social and psychological factors might have on the laboratory results.

Jan 1, 1982

By R L. Keller

Hong Kong has some of the most restrictive practices regarding blasting than any place in the world. Regulations regarding vibration limitations are 1 in/sec for structures and 0.5 in/sec (or even less) for most utilities; with no recognition of frequency response or adjustment. The Hong Kong Geotechnical Engineering Office has one of the most conservative approaches and protective guidelines for pre-blast assessment of slopes subjected to blast vibration (SEE paper '96). The protective measures to control flyrock generally required by the Mines Division are additionally very stringent. It is not uncommon for the costs associated with protective measures or methods which must be employed to exceed the cost of the drilling and blasting itself - or to waiver blasting application unfeasible altogether. From these restrictions it can easily be imagined how blasting in this urban environment would be most challenging.

Jan 1, 1997

By Malcolm Mellor

Practical procedures that have been developed for pre-split blasting and smooth blasting in common rocks are reviewed systematically. Topics covered include shothole spacing, charge weight per unit length of shothole, decoupling ratio, adjustments for explosive type and rock type, and weight of explosive per unit face area. Relevant properties of frozen rocks, frozen soils, and ice are compared with those of common unfrozen rocks, and appropriate adjustment of blast design is discussed. Interim relationships for the design of controlled perimeter blasting in frozen soils and massive ice are put forward, recognizing that additional experimentation is required. Special problems in controlled blasting of ice are discussed. These include effects of wet holes, delayed removal of burden, and submerged burden. Special attention is given to the cutting of ice islands and icebergs. An Appendix describes an operation in which the face of an ice wharf at McMurdo Sound was trimmed by pre-split blasting.

Jan 1, 1976

By Split Engineering Chile Fernando Fernandez

Mathematical modeling in conjunction with mineral characterization is widely used as a method for design and optimization of comminution circuits, to simulate the processes of crushing, grinding and classification. An important input parameter to the simulation models is the Run-of-Mine Particle Size Distribution (ROM PSD). The run-of-mine size distributions due to blasting have a great influence on the performance of a semi-autogenous grinding (SAG) mill. In this paper, a mine case study was conducted where there are four primary geologic units and the material properties between the four units vary considerably. Also, the mixture of the four unit that will be mined at any given time also vary considerably. This presents a challenge in terms of optimizing the blasting for mill production throughout the mine life. As part of the case study, field rock mass characterization, laboratory rock mechanics tests, and laboratory breakage tests were conducted. The field characterization and rock mechanics tests provide material properties used to simulate the effect of different blast designs on run of mine particle size distributions (ROM PSD). The JKSimBlast software was used for these simulations. The rock breakage tests provide material properties used to simulate crushing and grinding performance. The JKSimMet software was used for these simulations.

Jan 1, 2015

By Francisco Leite, Tomi Kouvonen, Bianca Saraiva, Vinicius Miranda, Auã Oliveira

One of the main challenges facing mining engineers is to draw up a plan that can be implemented in a timely manner, taking into account the operational variability of the mine’s production processes. These plans are often drawn up based on deterministic modelling (provided there are a set of known inputs that will result in a single set of outputs), when in truth we are talking about stochastic events (the cycles involved behave like random variables and their nature may be studied and reproduced). The result of using this kind of methodology can lead to non-optimized intuitive choices, which may harm the long-term targets defined by the planning team. Based on this principle, this document investigates the simulation of the rock fragmentation process in an open pit mine to assess the stochastic behavior of the loading and haulage operating cycles. The data assessed by the simulation process were the total costs of these operations in function of the powder factor. Based on a sample set data items, it was possible to check the probability distribution of the event as a Poisson distribution, applied to the loading and haulage cycles. The simulation consists of the repeated sequenced reproduction of these events (Monte Carlo simulation), in order to find the configuration that best fits the loading and haulage operations. By integrating these systems, it was possible to better understand the influence of the blasting in these operations, and as such to reduce the associated costs.

Feb 6, 2023

By Hans Perlid

In the handling of emulsion explosives pumping is a key operation. A number of serious accidents has shown that pumping can be a risky operation and should be care&lIy considered and investigated. This is the background behind a series of pump tests carried out by NTTRO NOBEL.

Jan 1, 1996

By Ruilin Lang

This paper presents an application of 3-D plots and non-linear regressions to define a sitespecific form of the charge weight scaled distance. The PPV (PPA) of single hole blasts is normally considered as a function of two independent variables - the charge weight and the distance. It is of great importance to obtain the relationship of the function accurately for a concerned site in terms of blast vibration analysis and modeling. However, in pre-computer time it was difficult to plot 3-D graphs. Consequently, a charge weight scaled distance was used to plot the PPV (or PPA) against the scaled distance as 2-D graphs. Blast vibration investigators use several forms of the charge weight scaled distances to plot data. We can exemplify them with the cube root of charge weight scaled distance, the square root of charge weight scaled distance, and other forms (Hossaini and Sen, 2004). Each of these scaled distances assumes relative contributions of the charge weight and the distance to the vibration attenuation. For example, the charge weight is assumed to have a less contribution to vibration in the cube root scaled distance than it is assumed in the square-root scaled distance. In reality, for different sites the relative contribution of the charge weight and the distance may be different and site-specific. This may explain that in some cases, the blast vibration data plots using these charge weight scaled distances are scattered. This could be largely due to the fact that the definition of the form of the charge weight scaled distance is not adequate for the particular site condition.

Jan 1, 2006

By Seokbin Lim

According to published literature, the equation of motion of linear shaped charges (LSCs) has been investigated as early as the 1960s in a few research organizations. However, due to the comparatively low penetration performance, the amount of research has not been extensive, and the use of this device is quite limited in very specialized applications. Traditionally, the equation of motion of an LSCs’ liner shares the same basis as conical shaped charges (CSCs) because they are under the same functional category and generally have similar geometric configuration. However, the nature of LSCs is not quite similar with that of CSCs due to multiple reasons, and they required a new set of equations to properly address their performance. In this paper, we reviewed different sets of approaches in describing the liner collapse behavior of LSCs mostly based on the author’s contributions.

Jan 1, 2014