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By Stephen Chung

The quality of a blast design can be evaluated in many ways. It may involve fragmentation, muck profile, environmental effects in terms of vibration and the excavation of the blasted material. To assist and ensure an achievable cost effective design, numerical modeling techniques are often applied as part of the operating procedure. While excavation is one of the mining operations which has a direct influence on the bottom line cost of productivity, the characteristics of a pile of blasted material deserves a closer look in terms of diggability. This paper reviews the current diggability techniques available for application to the blasting operation. To help better understand the involvement in digging, this paper also introduces an evaluation approach based on a discrete element method. The model presented in this paper deals with many variables that are considered to directly affect digging. They are the density and cohesion of material, fragment shape and size distribution as well as the swell of a muck pile. To help visualize the analysis approach, sample runs and animations are given in the paper to show the setup of muck piles produced in bench blasting as well as in sub-level caving. The computed forces experienced by the bucket during each mucking cycle are also discussed.

Jan 1, 2008

By P. Ravanal, J. Blazquez, F. Ortega, P. Couceiro, J. Navarro

Massive blasting technique is an interesting alternative to optimize mining’s performance by enhancing digging rates and overall operation’s activities, especially when a reduced operational bench width is available. The exploitation of a huge bench through multiple blasts would mean a potential reduction in productivity and higher operational difficulties. In such hard circumstances, combined with complex geotechnical conditions, a full ground vibration analysis for near and far field vibrations are required in order to safely design and conduct the blast. In this paper, a comprehensive case study will be discussed to show how the application of massive blasting techniques was safely implemented in very complex geotechnical conditions. The proposed solution was based on performing a full ground vibration study to optimize blast design parameters, such as charging and timing, in order to fire the complete bench blast in a single shooting event, without compromising the slope stability. Thus, a massive blast with an approximate tonnage of 6.0Mt was successfully designed and blasted, attending all safety and stability criteria defined by the geotechnical and drilling and blasting departments of Minera Escondida.

Jan 1, 2024

By G G. Paine, C V. B Cunningham, G Harries

The companies of the ICI Explosives Group have successfully used a wide variety of internal computer codes including BOBCAT, KUZ-RAM, ICRAX, XPLODE, BLEND, 3CRACK, MICBLAST, DETON, etc. In recent years the extensive experiences across ICI have been combined into a single compatible model engineered to worldwide technical service and customer needs for the prediction and assessment of blast results.

Jan 1, 1987

By Robert Pumpelly

During my nearly 30 years with ATF, (Bureau of Alcohol, Tobacco, Firearms & Explosives), I conducted hundreds of inspections. In many cases hours of time were wasted because the licensee or permittee, who had basically done everything right, was not prepared for the audit. In these cases, required documents were scattered, personnel were unprepared and no plan was in place. This paper will provide some simple steps to avoid these embarrassing delays. A list of common violations is also provided.

Jan 1, 2010

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 Garfiansyah Rayes

In 2023, an Indonesian coal mine experienced significant contamination of an emulsion blend explosive by dynamic mud and water flow, triggered by flooding due to exceptionally high rainfall. This intrusion into explosive columns compromised the stability and efficiency of blasting operations, thereby impacting overall mining productivity. The extent and impact of these contaminants on the stability and performance of the emulsion blend explosive were rigorously analyzed through a robust assessment methodology that included comprehensive field measurements and controlled laboratory experiments designed to replicate the challenging site conditions. Utilizing a combination of theoretical calculations and Computational Fluid Dynamics (CFD) simulations, this study evaluates the kinetic interactions between dynamic mud flows and emulsion explosives within drill holes. The methodology integrates Torricelli’s theorem for velocity assessments and Darcy’s Law for understanding the penetration mechanics of mud into the emulsion blend. CFD simulations are further correlated with actual blast data to assess discrepancies between theoretical predictions and real-world outcomes. Results demonstrate a significant reduction in the velocity of detonation (VOD) of the explo-sives, traced directly to mud contamination levels, which align with the quantified penetration rates in the study. Practical measures for mitigating such contamination are proposed, including the reinforcement of water-ways, culverts, and bund walls at drilling locations based on validated simulation data. Additionally, rec-ommendations for operational adjustments during high rainfall events are discussed, aiming to enhance blasting safety and efficiency. The paper concludes by suggesting future research directions towards the development of more resilient emulsion formulations and enhanced predictive modeling techniques to better forecast the impacts of en-vironmental variables on explosive performance in mining operations

Jan 21, 2025

By Italo Onederra, Gary Cavanough, Ewan Sellers

Reactivity of ammonium nitrate based explosives is associated with the presence of iron sulfides in the ground reacting with explosive products and in some instances causing spontaneous reactions which can lead to detonation. The stability of explosive products can also be linked to in-hole density, which influences detonation efficiency, breakage performance and the potential generation of Nitrogen Oxide (NOx) fumes. Reactive ground testing involves detecting a temperature rise of a mixture of a bulk explosive product sample, a ground rock sample and some specific chemical agents. This paper describes improvements in reactive ground testing involving the use of time lapse video analysis and detection of NOX gas emissions from the sample. Reactivity is stored and linked to a using cloud based software to map of the mine showing the exact location of the sample. The location marker can be selected to allow quick access to the sample test results and video. In addition to reactivity, the stability and detonation performance of bulk product can also be influenced by depth. In this paper, a system that simulates product at depth and measures density changes and monitors the structure of bulk samples is described. Results from an explosive product are analyzed and detonation performance is assessed by the measurement of velocity of detonation and detonation pressure.

Jan 1, 2018

By D P. Proudfoot, S G. Keith, D P. Onagi

A number of aspects of the Canadian concept for nuclear fuel waste disposal are being assessed by Atomic Energy of Canada Limited (AECL) in a series of experiments at its Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, Canada. One of the major objectives of the work being carried out at the URL is to develop and evaluate the methods and technology to ensure safe, permanent disposal of Canada's nuclear fuel waste.

Jan 1, 1996

By Javier Castaneda, Luis Zozaya, Noel Huarachi, María Rocha

The objective of the project was to implement and calibrate drill and blast models supported by Geotechnical and Geological models as well as the mine and operation characteristics. The models would then be migrated to HxGN Blast to ensure a productive process that is simplified, digitized and optimized.

Feb 1, 2020

By Jorge Alvarez

In a large-scale open-pit mining operation, continuous efforts are made to control damage to the slope walls. An essential tool in this effort is determining the PPVc (critical peak particle velocity) in areas of interest. By knowing this value and generating criteria, drilling and blasting designs can be established to reduce vibrations that affect wall construction. It is crucial to understand that the PPVc changes as different mining phases develop, especially due to exploitation on the benches, which leads to vertical inherited damage. Therefore, it is imperative to regularly update the PPVc based on field tests that provide accurate data. With this information, vibration damage criteria can be established, and drilling and blasting techniques can be designed to minimize the impact on the remaining rock mass. This document presents a methodology for generating scaled criteria that best represent the reality of the rock mass.

Jan 21, 2025

By Pavel A. Torres, Darwin Torres, Sandro Huaman

Given the limited efficiency of blast-induced ground vibrations prediction empirical models, due to the complex geological system from a Peruvian mine. An artificial neural network was built in order to get better results. More accurate and precise predictions allowed the generation of blasting domains for future designs and decision making.

Feb 1, 2020

By Tie-jun Tao, Ming-sheng Zhao, En-an Chi

"Karst landform is a special kind of geomorphic unit which is often accompanied by a large number of geological defects: caves. In blasting engineering, if there are karst caves around the blast-holes, it may result in higher boulder yield and the generation of flying rocks due to the change of burden which is very hazardous for the safety of surroundings. The models of rocks with karst caves from blasting holewere built by the software of ANSYS/LS-DYNA. The results of computation simulation show that thecave can increase more free surface for blasting and leads to a broken zone around itself. Thus rockmass around the cave will fly toward inside and it will result in undesirable result of whole rock mass to be blasted. In addition, the models of rocks with karst caves in different shapes were simulated and thecomputation results show that the caves in round shape have higher load resistance capability than that the caves in rectangle shape. All the simulation results can offer effective guidance for blasting design. The models of rocks with karst caves were built in different distances and shapes from blasting hole by the software of ANSYS/LS-DYNA. The effect of different karst caves on blasting stress and blastingresult were studied."

Jan 1, 2017

By Lauren Shields

This paper discusses the application of current fragmentation models for underground blasting, establishes a conceptual fragmentation model for underground operations, and discusses the applicability of the mine-to-mill approach for underground blasting. Additionally, this paper also discusses selected case studies where the mine-to-mill approach is applied to underground mining operations.

Feb 1, 2020

By Roger L. Keller, John Dean Smith

The Amax Coal Company's Ayrshire Mine in Southern Indiana is faced with one of the toughest blasting applications concerning vibration in the nation. As a means of maintaining regulatory compliance the operation elected to exercise the option of frequency analysis. A site-specific computer processing program which suggests ideal delay interval ranges for the lowest vibration was utilized.

Jan 1, 1987

By Maria Sullivan

There have been many papers and articles presented over the last 60 years questioning the relevance of the 8-millisecond blasting delay window as an ‘Industry rule of thumb’. The concept of using delays between blast holes to minimise vibration is well understood and agreed upon. The means for evaluating what that minimum delay interval needs to be, for a particular site given their ground conditions, design parameters and blasting techniques, is much less established. Some sites haven’t even recognised their required minimum delay value may not be 8-milliseconds!

Feb 6, 2023

By Markus Pötsch, Andreas Gaich

Optimization of surface blasting based on 3D models from drone imagery and a closed loop that starts with an automatic analysis of the geometry and the geological conditions and ends with an objective assessment of the blast result.

Feb 1, 2020

Investigating blast vibrations typically utilises scaling and attenuation models for prediction of vibration amplitude over a range of charge weights and distances. A number of generalised relationships have been established from many years of far-field data analysis, where small changes in charge weight and ray-path distance are less critical. Under far-field conditions, small variations in local geology or geometry do not significantly affect the vibration scaling behaviour over an expected range of data. In the near to intermediate-field (less than 5 times the explosive charge length), small variations in wavepath and rock mass conditions between a blast and a monitoring point can greatly affect the outcome of vibration modelling. This case is especially true for underground blasting in sublevel open stoping, where the paths of blast-induced vibrations regularly encounter voids and preconditioned ground.

Jan 1, 2010

By Tom Watts

This paper will focus on the design, manufacture and use of pump safety systems on MMUs (Mobile Manufacturing Units – Bulk Trucks) with progressive cavity pumps. The practice of pumping bulk blasting agents is highly regulated and the explosives manufactures have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping.

Jan 1, 2009

By Ruilin Yan, Kameron Ray

This paper reports a simple approach to model the waveform change due to travel distances based on the field measurement. A linear interpolation is used to estimate the waveform at a distance from two vibration waveforms recorded at two different distances. The resulted waveforms are compared with actual recorded waveforms at the point in both time and frequency domains. It shows that the proposed method to estimate the waveform change yield reliable results. The advantages of the proposed method are that it does not require assumptions that a transfer function does and that it is based on purely the measured waveforms that are encoded with in-situ rock properties. The method could be more reliable for far field seismic waveforms and could be an approximation for near field waveform estimation.

Jan 1, 2014

By Bonifacio Digay

Stawell Gold Mines (SGM) is an underground mining operation located in Victoria, Australia.The mining method employed is long hole retreat stoping, utilising up and downholes and artificial concrete pillars. Stawell is currently mining the Golden Gift and Magdala orebodies.

Jan 1, 2012