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By Gustavo Huerta Valer, Jorge Cárdenas Miranda, Johan Salas Flores

One of the challenges of mining is the optimization of the blasting process, which has an important impact downstream in the processing of crushed ore in the plant, that is why mining companies ensure the results of granulometry obtained from the blasting process through a joint work with companies specialized in the process of loading with explosives.

Feb 6, 2023

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 Daniel Scott

Mines have used explosives for economical fragmentation for many years. It can therefore be expected that the mining industry has thoroughly researched how to achieve the most efficient blast. However, there is still a large amount of iteration that must be undertaken before blasting at a mine site can be refined enough to allow for consecutively successful blast results. And then the geology changes. This paper will present an approach to blast design that considers production goals, geology, budget, and safety, and will contrast the proposed method with well established blasting theory.

Jan 1, 2012

By W B. Gregg

"A review, update, and expansion of Thiokol’s presentation at BAl’s Fiih High Tech Seminar titled ‘ADetonator - An Era of Precision in All-Electronic Detonators” is provided herein (and should be considered as a supplement to that publication). Thiokol is currently in the development and field evaluation phase of activities for our ACCUBLASTTM all-electronic detonator. The ACCUBLASTTM detonator uses a semiconductor bridge (an electronic match) in place of a conventional hot wire to initiate a safer, less sensitive material, titanium subhydride potassium perchlorate. The device is programmable to provide blast delays in one millisecond increments ranging from 1 to 500 milliseconds. The ACCUBLASTTM detonator combines an all-electronic programmable timer coupled with a semiconductor bridge to ensure detonation timing accuracy with +I00 microsecond precision. Initial development and field testing have been completed. These tests have verified ACCUBLASTTM detonators’ precision."

Jan 1, 1995

By Duan Baofu, Wang Xuguang, Song Jinquan

In this paper, the model of optimizing selection on preparation of Powdery Emulsion Explosives(PEE) is established by the Neural Net Theory(NNT). On the basis of some data in the study of PEE, the training, prediction and optimizing selection of the Neural Net (NN) model are finished by a compiling procedure. The results indicate that the model is helpful to the preparation of PEE and worthy to extend and apply broadly. KTYWORDS Neural Net Powdery Emulsion Explosives Preparation Optimizing Selection

Jan 1, 2003

By Perry Sisk

In order to protect nearby structures during a blasting project, a peak particle velocity limit is often stipulated by a government agency or the owner of a particular structure. At the start of a blasting project, a preliminary estimate for the minimum scaled distance is often determined using a vibration prediction equation before any site-specific data have been obtained. Reasonably conservative assumptions are typically made for the unknown input variables in the vibration prediction equation until site-specific blasting data have been obtained and evaluated. Although this approach is prudent, it provides no assurance that the peak particle velocity values generated during the initial phase of the project will be below the specified limit.

Jan 1, 2013

By Weiying Zeng, Shouwei Wang, Jinbei Zhong, Xiangdong Meng, Lingtian Meng

"Due to a drainage problem, the Lanzhou to Chongqing high-speed rail line had been out of service during the 2015 wet season, so a drainage tunnel is to be constructed for the line and required to be accomplished before the 2016 wet season. This drainage tunnel is only 5 meters below the line which is in service, therefore blasting vibration needs to be strictly controlled. This paper introduces all theapplied blasting methods, parameters and detonation throughout the entire project, finally bringing in the electronic detonator stagger phase technique and corresponding time difference for detonation."

Jan 1, 2017

By Ximing Yuan, Yongsheng Xu, Hongjie Li

A study of a static demolition agent that can be used underwater has been carried out. A new type of granulated static demolition agent with rapid reaction has been tested in several hundred experiments. It can be used conveniently and simply in the field. It demonstrates a fast reaction rate with high expansion pressures. The important characteristic of the new type of granulated static demolition agent is the ability to function underwater. It will destroy rock and the other brittle material without flyrock, vibration, shock wave, toxic gas or noise. The reaction rate can be controlled within 30-60 minutes. It is difficult to use these products when the reaction rate is less than 30 minutes and it is less efficient when the reaction rate is longer than 60 minutes. The reaction rate is slightly increased after the material is kept in storage for two years. A new type of the hydraulic device that is used to measure the expansion pressure of solid materials has been designed. The expansion pressure of the granulated static demolition agent has been tested with the device. It is shows that the expansion pressure of the granulated static demolition agent can get to 80~120MPa in 60 minutes. Also included is a discussion of the thermodynamics of the static demolition agent.

Jan 1, 2003

By George W. MacDonald

ALFRED NOBEL was born at Stockholm on October 21st. 1833, and died on December 10th, 1896. Although Sobrero’s discovery of nitroglycerin dated back to 1847, this explosive was manufactured on a commercial scale for the first time in 1862, by Nobel at a factory which he erected at Heleneborg, near Stockholm. These works were entirely wrecked by an explosion in 1864. In 1865, he erected works, which are still in existence, at Winterviken, near Stockholm. In 1864 Nobel introduced modifications in the manufacture of nitroglycerin which were the subject of a patent (see footnote No. 1), and at the same time, claimed a process for the detonation of nitroglycerin. Nobel states that, up to that time, the method used for the manufacture of nitroglycerin consisted in pouring glycerin, drop by drop, into a mixture of sulphuric acid and nitric acid contained in a refrigerating mixture. In order that the nitroglycerin should not be decomposed, the temperature was not allowed to rise above 0° C.

Jan 1, 2012

By Kenneth Etschlager

The ISEE Blast Vibration and Seismograph Section provides a forum for the discussion of issues related to vibration and noise from mine, quarry and construction blasting. The section began as a Technical committee in 1995 to promote the accuracy of blasting seismographs. Currently five subcommittees exist within the section: Seismograph Standards; Seismograph Testing and Calibration; Vibration Limits, Technical; Vibration Regulations; and Program and Communications. Foremost, the Seismograph Standards section wrote the first two technical standards adopted by the ISEE. The historical accomplishments, current activities and objectives of the section are discussed.

Jan 1, 2003

By L. Wilson, M. Kotzel, T. Pienaar

An empirical equation is presented for the maximum airblast from unconfined charges. This has been tested at a number of sites and with charges ranging from 0.1kg to 311kg. The equation is developed to predict community response to potential explosive test range sites and the testing has added to our knowledge of the effectiveness of mitigating measures. The first site had 10m to 15m high walls that were intended to ameliorate the airblast. These walls functioned to a limited extent and reduced the airblast levels by 2dB to 5dB. The airblast was affected somewhat by topography. Noise levels at the nearest residences exceeded 130dB for charges larger than 1kg, whereas the vibration levels were very small. Formal complaints were received where the airblast level exceeded 128dB as per conventional expectations. Pedestrians and pets in the suburbs were startled by the blasts, emphasizing that the community response is much more sensitive to noise and airblast than vibration levels. The maximum airblast levels were too high for this site to be used on a regular basis. At another site, the airblast levels were significantly increased downwind by up to 10dB due to a moderate wind. A third site, at a quarry, produced unconfined airblast levels beneath the derived limits, but are much higher than the normal quarry blasting. By involving community forums there were no complaints, possibly due to desensitization by the normal blasting activities. The study has highlighted new areas for research in understanding the effect of noise, air blast and vibration on the low cost and informal housing typical in South Africa

Jan 1, 2011

By Chris Vagasky

On July 10, 1926, lightning struck at Picatinny Arsenal, New Jersey, and caused the explosion of at least 600,000 pounds (272,000 kilograms) of ammunition, resulting in more than $600 million (2015 dollars) in damage, the destruction of 200 buildings, and 22 deaths. Fortunately, there has not been a major incident involving lightning and explosives in the US in some time, though lightning has destroyed fuel storage tanks in recent years, including in North Dakota, Texas, and Ohio. Lightning poses a significant hazard to the explosives industry. Carrying high currents and temperature, lightning can cause explosives to detonate, start fires near storage facilities, and injure or kill operators.

Jan 1, 2017

By Jorge Cárdenas, Alejandro Luna

In mining simulation for fragmentation results prediction is of utmost importance to study feasibility, ensure safety, and estimate the correct use of resources in drilling an explosive to meet requirements and avoid excessive usage. One critical case is fragmentation prediction, developed through models. Developing a fragmentation model in a mining unit aims to control blasting results to align theoretical and real data and improve correlation. Therefore, it is essential to collect post-blast fragmentation data, organize it, and systematically process it to develop a suitable model that meets variable requirements. Using a robust system of equations, this model should generate the required results with minimal variability between simulation and actual results. Additionally, this model must be adaptive to reduce this variability. Studying the most known and used models in mining resulted in our work correlating Cunningham 2006, Swebrec, and CZM models. Thus, the Simfrag model was created, presenting a robust foundation and combining the most notable advantages of the aforementioned models.

Jan 21, 2025

By Benoît Pinier, Jason Furtney, Gustavo Sampaio Lopes, Jorge Valencia, Johan Hawinkel

This paper describes a numerical modeling study on the effect of airdecking on vibrations, fragmentation, and movement in mining-related rock blasting. Practice has shown that air gaps reduce blast vibrations and damage while maintaining the required fragmentation and movement, yielding similar blast outcomes with less explosive mass per hole. Given that the premise of “replacing explosives with air” for better blast results is counterintuitive, this paper aims to shed light on the physical mechanisms and processes occurring in a blast with airdecks. It is hypothesized that airdecks are effective and beneficial because they load the rock at pressures lower than what is required to crush the rock. In the airdeck, the explosive gasses directly fracture rock and avoid energy loss due to crushing. In essence, the airgap allows similar outcomes in fragmentation and throw with less total explosive product, as the lower pressure gasses in the airdeck are still effective at breaking and moving the rock. This is distinct from only having less explosive and more stemming, as the stemming reduces the pressure more than an airdeck at the same position. This study uses the blastFoam software (for modeling of single and multiphase flows) to accurately calculate the pressure history throughout a blasthole and air gap. The pressure and gas loading are coupled to numerical models of vibration, fragmentation, and blast movement. Using this modeling technique, a suite of blast scenarios for typical configurations in a range of commodities is assessed with and without airdecks. Rock blasting practitioners have a responsibility to protect communities, infrastructure, and heritage — demystifying airdecks through a better understanding of the physics provides another tool in the blasting engineering toolkit to serve this goal.

Jan 21, 2025

By G. Geremia, M. I. Serrano, L. Costa, Strohaecker

The advances in electronics and the development of more efficient algorithms, allow for the designing of more complex and sophisticated automated systems. The new devices include lighter, faster, reliable, and stronger robot manipulators. One available technology, with relatively low cost, is a simple robot manipulator controlled by remote control. The device has been designed to be used in both mining and law enforcement, where it can be useful for inspection, rescue, gas analysis, and even to manipulate dangerous objects, such as explosives. The applications may even include the rescue of trapped miners in risky environments. The major advantage is the fact that the robot can be controlled with a remote and monitored through a video camera, minimizing human exposure to hazardous areas, where robots can perform tasks in an aggressive atmosphere and confined spaces. This article presents a mining robot manipulator controlled by remote control, using video cameras for positioning and sensors for movements, which are located on the operator's arm. With this system, it is possible to create a sensation of virtual reality, allowing easy operation for anyone trained in dealing with explosives, rescues, or other dangerous tasks. Blasting and mining are becoming perfect applications for robots, and its use should increase very soon. The results are discussed and presented for the brand new Xiru 01 robot manipulator.

Jan 1, 2010

By Francisco Sena Leite, Raquel Sobral, Vinicius Gouveia de Miranda, Céu Jesus

"The urgent need for improvements in the control and mitigation of environmental and social conditions associated with the extraction and processing of raw materials is increasingly a demand imposed by legal entities and institutions. Therefore, this present article proposes an improvement of the estimation in the magnitude of the vibrations resulting from rock blasting methodologies in the surrounding areas,incorporating the heterogeneity caused by uncontrollable parameters, such as geological andgeotechnical characteristics. This methodology combines the use of empirical vibration attenuation lawscommonly known and with terrain discretization techniques using Voronoi’s decomposition. For thevalidation assessment of this methodology, the data set collected and compiled is composed by 87 vibration measures collected in 16 sample points in one area of study of which 2/3 of the samples were used to create the model and 1/3 for the validation. Using normality tests for statistical residue analysis,it is possible to infer that this present model has null residual mean, as well as a smaller sum of residualerrors. Comparing the methodology present in this paper with the procedures executed nowadays, areduction of the errors associated with the estimation is obvious, highlighting a better characterization of the behavior of the vibrations associated with rock blasting."

Jan 1, 2017

By Sandy Tavelli, Thomas L. Barkley

This discussion will present a case study in developing solutions to a metropolitan quarry’s public relations, legal, environmental, and productivity problems. It details an extensive and detailed project to address the blasting practice in a medium sized quarry that is surrounded by residential and industrial zones. The principle work was done over a four-month duration during the normal production season. It included detailed drilling and blasting audits for baseline information. In addition, geologic characterization, seismic modeling, correction of deviations from best practices, and implementation and monitoring of precise electronic timing to provide dramatic solutions for the quarry. The quarry is in the near suburbs of a large metropolitan city. It is framed on two sides by residential municipalities and on two sides by industrial zones. At the start of the project, the quarry was in court as a result of the lawsuit by one of the neighboring towns that was suing to close the quarry. The lawsuit had progressed to the advanced stage where in the Judge had appointed an arbitrator to make the decision of continued operation. This arbitrator was to observe our progress and recommend to the Judge the disposition of the case.

Jan 1, 2004

By Tom Snyder, John Brulia

"The U. S. commercial explosives industry annually transports thousands of tons of hazardous materials (HM) in the form of explosives, oxidizers, and combustible liquids by highway in truck-tractor/trailer combinations and straight trucks, including pickups. Managing risk during transportation is every commercial explosives industry motor carrier’s number one job."

Jan 1, 2014

By Angelina Anani, Seffit Aderuyi, Sylvester Avane, Joseph Wilson-Sey, Amatus Niminye

The Edikan mine in Ayamfuri, Ghana, faces economic challenges and community resistance due to its proximity to residential areas, particularly concerning blasting operations. Controlled blasting trials using air deck applications were conducted to address community concerns by minimizing environmental impacts and explosive costs. This method involves utilizing an air gap within blast holes to prolong the action of shock waves on the rock mass, enhancing crack formation and reducing rock movement. The trial project at the Edikan open pit gold mine aimed to evaluate the effectiveness of air deck blasting in reducing ground vibrations and overpressures, and to assess its impact on blast performance and economics in the prevailing geological conditions of meta-sediment and hard granite rocks. Results indicated lower Peak Particle Velocity (PPV) and Peak Sound Pressure Levels (PSPL) values in the air-decked blasts. Additionally, more uniform rock fragmentation and enhanced blast economics were achieved. Explosive costs were reduced by 20–24%, saving $0.97 to $2.24 per hole depending on the rock type. Overall blasting costs per volume decreased to $0.54 in granite and $0.48 in meta-sediment compared to conventional methods.

Jan 21, 2025

By Luiz Felipe Mendonça de Amorim, Adimir Fernando Rezende, Gustavo Sampaio Lopes, Claudio Cesar Gajardo Arraño, Eltton de Sousa Veras, Manuel Villalobos Calderon

Many technical challenges were encountered while conducting near-field construction blasting between the critical intersection of Interstate 10 and multiple active railroad tracks in El Paso, Texas, for the Loop 375 Border West Expressway Project. Blasting was utilized for the removal of an andesite bedrock ridge in preparation for the construction of a new elevated super structure to be suspended over the existing railroad tracks. There was concern that the excessive vibrations and/or permanent rock deformation produced from the blasting within near proximity (20 feet, or 6.09 meters) of the railroad tracks would induce excessive stress and foul the tracks by shifting the alignment. This could result in a major loss of scheduling control between the two major railroad companies that operate in this area. There was also concern that the blasting may cause rock fragments to land on and interfere with critical interstate transportation. Blasts

Jan 1, 2019