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By María Virginia Ramírez, Alejandro Alarcón, Alea Reyes

Reactive grounds (presence of FeS2, CuFeS2) can create hazards in a mine; misfires to premature deflagration or detonation of loaded blast holes. This occurs because some minerals can react to ANFObased explosives. Due to a high potential event that occurred in The Mine in 2013, The Mine and the Explosive Provider (“The Company”) are conducting a soil characterization of the areas containing reactive sulfides. This study was planned along with The Mine and it is being developed by a multidisciplinary team.

Jan 1, 2018

By Pierre DePasquale, Ricardo Chavez

Lowering of quarry energy consumption participates to answer both environmental and financial issues. The “EE-Quarry” European project, supported by the European Commission (EE stands for Energy Efficient), develops a new and highly effective modelling and monitoring Energy Management System technique to improve Energy Efficiency and move to a low CO2 emission rate in the nonmetallic mineral industry. Within this global quarry project, blast design, as the first link in the chain, has to be optimized in order to satisfy requirements of downstream operations. The authors have been developing and implementing an operational methodology using continuous field measurements and field adaptation methods for blast design. It drives the drilling and blasting work, aiming at a more energy efficient and environmentally friendly operation. Based upon actual local conditions (rock-mass assessment, face geometry, borehole deviations, etc.), blast patterns are optimized through a specific hole-by-hole blast design software. It provides a better and more consistent energy distribution, to achieve a better rock fragmentation, while avoiding explosive overconsumption. The software also calculates total energy inputs and the drilling and blasting contribution to Greenhouse Effect. Coupled with methodical fieldwork and variable density explosives, it has been leading to a real reduction in energy costs and greenhouse gas emissions. As the project is now reaching its final stage, demonstrations were conducted in various quarries around Europe. Several simulations were carried out and compared to the site data, in order to propose enhancements for the different phases (extraction, loading, hauling, crushing and transport) while bearing in mind the environmental impact of the quarry. This blasting methodology allows to assess the carbon footprint of drilling and blasting in conjunction with the downstream operations, thus to evaluate the global carbon footprint of quarrying. Copyright ©

Jan 1, 2015

By L. M. Lopez, J. A. Sanchidrian

This work investigates the performance of some of the measurement techniques used in vibrations from blasting monitoring. Two tri-axial geophones with cases of different size, shape and mass were tested in a shaker table. The geophone cases were mounted in three different ways on a granite slab fixed to the plate of the shaker: freely placed, sandbagged, and anchored. A known horizontal periodic motion of constant amplitude, and frequency from 16 to 200 Hz, was applied to the slab. Two amplitude levels of 5 and 20 mm/s (0.2 and 0.79 in/s) were applied when the sensors were sandbagged or anchored and only 5 mm/s when no holding force was applied. The transmissibility of vibrations from the rock to the longitudinal geophone as function of the frequency (i.e. ratio of response of the geophone to the slab motion) has been obtained for each measuring condition tested. The transmissibility is considered a composition of the transmissibility of the rock-to-sensor coupling and the transmissibility of the sensor’s mechanics and electronics. The transmissibility of the coupling is obtained normalizing the total transmissibility with the transmissibility of the seismographs, obtained by a suitable test to which a coupling transmissibility of 1 is assigned. Geophone-to-rock coupling is a resonant phenomenon that may alter the amplitude of the measured waveforms by a factor of 1.2 to less than 0.6. The most accurate and precise measurements are obtained with geophones anchored to rock. On the contrary, freely placed or sandbagged sensors are non-predictable planting conditions that lead to high amplification or damping in most of the frequency band analyzed. It is also shown that existing acceleration criteria to select coupling methods do not necessary lead to good quality (accurate and precise) vibration data.

Jan 1, 2014

By Frank Lucca

This study is based on a six month study performed for Lee County, Florida. The study was based on blasting for land development and how this type of blasting affects structures. The study is investigates peak particle velocities and the relationship to other environmental and manmade forces that affect structures. The study also explores the effect of geology on blast vibration. After completion in Lee County, the study was then continued in the quarry environment in Vermont and extremely tight blasting environment of New York City. Charge diameters were 127mm (5 inches) or less.

Jan 1, 2006

By Matthew Baumann, Bahram Sameti, Tafazoli Zeng Hairong, Edmond Chow

An automated, centralized, image-based rock fragmentation analysis system provides blast engineers with the benefit of minimizing tedious and mundane work, and allows them to focus on their expertise of blast optimization. In typical manually-operated image-based rock fragmentation analysis, much time is spent on collecting proper images, handling and transferring data, and processing for fragmentation.

Jan 1, 2013

By Benjamín Cebrián, David Flores, María Rocha Gil

This document shows the evolution of drilling and blast digitization process, savings and trends in a mine, using new technologies that creates business opportunities and general improvement of D&B process.

Feb 1, 2020

By Benjamin Cebrián, María Gil, David Flores

In many occasions during the Mining operation life, blasting engineers find different and controversial results of fragmentation, dilution or wall control for the same geotechnical domain and blast design (pattern and explosive charge). Most of the times, the difference between same blast designs is not measured, not controlled. Once a blast designed is defined, the most important part of the process after that is the implementation of every step of the blast on site. Almost nobody is measuring it, controlling it, but just controlling implementation is possible to relate blast design with results in a consistent way, to optimize the full process of D&B. Controlling implementation not only per event but also to check and change trends and decision-making is paramount for optimization and saving millions of extra costs every year. The lack of resources and the hardness to manage all the info created every day in a blast make this process very tough and difficult to maintain in long term. The use of new technologies on site and software that allows a best, more consistent and continuous control of blast implementation have been proved to be the key for optimizations and cost saving. This document shows the evolution of drilling and blast digitization process, savings and trends in a mine, using new technologies that creates business opportunities and general improvement of D&B process.

By Michael Wieland

Sharp transient stress waves generated during the delay blasting of underground coal can damage unfired borehole charges remaining in the delay pattern. These tremendous stress pulses in coal bear a strong resemblance to underwater shock waves, despite differences in rise times, damping rates, and scaling relations. "Shock wave" terminology is adopted to distinguish the sharp transient waveforms propagating through the coal from the gas-driven stresses that rift the coal. Reported waveform characteristics of shock waves through underground coal were utilized to design a simulator test for rating the impact resistance of cap-sensitive explosives. Theoretical minimum borehole separations were determined for each cap-sensitive explosive from the requirement that worst-case waves hitting an unfired charge would not exceed its impact resistance rating. Rugged explosives have higher impact resistance and will function properly at smaller borehole separations. Additional work is required to verify the findings from the simulator technique and modeling relations reported here.

Jan 1, 1990

By A. K. Sirveiya

A major concern with blasting at surface mines is generation of ground vibration, air blast, flyrock, dust & fume and their impact on nearby structures and environment. A study was conducted at a coal mine in India which produces 10 million tonne of coal and 27 million cubic meter of overburden per annum. Draglines and shovels with dumpers carry out the removal of overburden. Detonation of 100 tonnes of explosives in a blasting round is a common practice of the mine. These large sized blasts often led to complaints from the nearby inhabitants regarding ground vibrations and their affects on their houses.

Jan 1, 2005

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 Zoltan Susanszky

The total available energy in an explosive charge is seldom fully utilized in industrial operations. For this reason more explosive is normally used to perform a job than we would calculate. In an explosive detonation some energy is generated as waste energy which can not be efficiently used. This results in added expense and possible environmental damage. This waste energy can create problems in metal forming with explosives and during commercial underwater blasting operations.

Jan 1, 1976

By Dadan Munawar, Benny Gunawan

Blasting at Sebesi in Central Tutupan Pit area in South Kalimantan, Indonesia is planned to be using emulsion, where used oil makes up 50% of the total emulsion fuel. The significant amount of used oil from various mining operation units had been of deep concern since it might be reused to implement environmental programs by substituting 50% of fuel with used oil in emulsion, thus decreasing fuel consumption and increasing efficiency by reducing fuel cost. Used oil must pass laboratory test to meet the Indonesian National Standards (SNI) No. 7642:2010 of used oil specification. Other considerations include the location which is adjacent to the mine office facilities with a radius of <1,750 meters (5,741 feet). Thus, appropriate methods must be performed to meet the SNI No. 7571:2010 of vibration threshold in order to implement safe blasting technique and prevent potential damage.

Jan 1, 2015

This paper describes the circuit simulations based on SPICE of the SDI Electronic Detonator System at the system level. SDI is launching the Electronic Detonator System with a robust serial protocol exhibiting great ease in field usability and deployment. Programmable delay time with increment of 1 ms up to 10s is possible. Bus length of up to 2 km containing 1600 detonators can be utilized. This system was analyzed using SPICE simulations and an Excel-based firing model spreadsheet. The effects of wire diameter, resistivity, detonator leakage characteristics, blasting array topology (lumped, linearly distributed or branched) were simulated using the firing model. Such spreadsheet is instrumental in determining the blasting topology of any given detonator number and bus wire diameter or resistivity. Initial simulation results were interactively coupled back into making the serial protocol more robust during typical mining conditions.

Jan 1, 2006

By Ronald Joseph

Windows-based automated blast loading systems have long being conceptualised and never really taken off in the surface mining sector. However, with the introduction a windows-based automated blast loading and reporting system onto the Mobile Manufacturing Units (MMU’s) at Debswana Diamond Company operations in Botswana in August 2004, a project to automate blast loading (charging) and reporting ensued. This work was pioneered over three phases at Debswana’s Jwaneng Diamond Mine by African Explosives (Botswana) (Pty) Limited as part of the African Explosives Limited’s (AEL) integrated-mining (i-mining) concept. The first phase of the project involved the blast reporting system, at which time an average amount of explosives were loaded into all blastholes and all blast loading information was saved to a Microsoft Access 2000 database on the MMU computer. The second phase of the project, which ran until the end of the second quarter of 2008, involved manual blast plan loading and reporting system using flash disks, and the third phase which was installed and commissioned in the third quarter of 2008 and is currently operational at Debswana’s Jwaneng Mine, involves the automated blast loading and reporting system via Wireless Local Area Network (WLAN). This system is now routinely used to achieve operational and mining efficiency goals at the mine with respect to blasthole charging and blasting, and this paper briefly summarizes the status of this project at Jwaneng Diamond Mine where this technology is currently being monitored and also illustrates the positive mining impact that this innovation brings to the mining operation, both from an economic and efficiency perspective.

Jan 1, 2009

By Lon Santis

This paper describes several applications of quantitative risk assessment in the management of commercial explosives operations. The Institute of Makers of Explosives’ (IME) quantitative risk assessment software modeling program IMESAFR was used for this analysis. Modeled activities include the unloading of a ship at port, locating a safe haven, and dealing with encroachment on a manufacturing facility. The layout of actual explosives sites were used for the analysis. The risk of fatality is analyzed and shown it can be used to make informed operational decisions for each activity. A study of the risks to individuals from activities involving commercial explosives compared to individual risks from other daily activities or exposures is also presented.

Jan 1, 2008

By P A. Gibson, J R. Brinkmann

The South African gold mining industry fires approximately 800 000 sloping blastholes daily. A programme aimed at characterizing the stope blasting process is underway in order to identify areas for improvement and to provide blasting related information for the design of mechanized sloping systems.

Jan 1, 1985

By Chuck Kliche, Bill Clements

This project involved the removal of the top of an old water supply reservoir tank for the City of Lead, SD by explosives. The general contract called for the removal of the concrete top without damaging the sides or floor of the reservoir. The option of a rock hammer was eliminated, due to the possibility of an unpredictable collapse damaging the sides or floor of the reservoir. Different blasting options were discussed between the primary contractor and the blasting contractor, along with the pros and cons of each. The primary contractor settled on the option of drilling the structure for blasting versus using shaped charges

Jan 1, 2007

By Jim Petrunyak, Conny Postpack

The authors describe in this paper a systematic approach toward reducing coal production costs up to 35% through the use of explosives energy for overburden removal. In this system, explosives are employed to blast as much as 65% of the overburden instantly from highwall to spoil pile, with only the lesser portion requiring removal by dragline, shovel, or loader.

Jan 1, 1983

By Shawn Kirkpatrick, Yang Ruilin, Tamara Whitaker

In order to manage blast vibration in soft ground containing large diameter holes and large charge weights, a number of issues must be considered. This paper describes techniques to control and reduce near-field blast vibrations absorbed by highwalls in soft ground. Sympathetic detonations need to be controlled. Sympathetic detonations can cause excessive vibration due to an unknown number of charge weights firing out of sequence. The excessive vibration can cause damage to the ground. Sympathetic detonations can be controlled through proper design of blast patterns and, in some cases, through the use of specialized electronic detonators.

Jan 1, 2009

By Charles Zdazinsky

Back-break induced from blasting is a concern in open pit metal mining because it compromises the conditions of the pit’s final walls. Final walls that have excessive blast induced damage commonly require extra attention and can often lead to increased cycle times. Most importantly however, the safety conditions of a back-broken region can be significantly compromised and it must be addressed to prevent injury and/or damage to equipment. This occasionally results in the necessity to alter mine plans to prevent an incident from occurring in a back-broken region which can be costly to the mine.

Jan 1, 2014