Search Documents

By Wilfrid Comeau

Vibrograms, which last significantly longer than the actual blast (say 10 to 15 cycles or more), may be signalling an elastic response, which is not uniquely blast related. For example, geophones mounted on a part of a structure, which can elastically resonate at a frequency included in the seismogram, may not show the structure’s real reaction to the blast. This resonance usually amplifies the ground vibration. This contribution examines one particular case where blasting excited and amplified a resonant ground response, and the method used to significantly reduce or eliminate this undesirable condition.

Jan 1, 2007

By Tom Watts

The practice of pumping bulk blasting agents is regulated by many agencies around the world. The explosives manufacturers have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping of water based blasting agents. The challenge of a Bulk Trucks or Mobile Manufacturing Units (MMUs) manufacturer is to take the objectives of the regulatory agencies and the explosives manufacturers and responsibly design and build MMUs that are safe, compliant, and cost effective without compromising serviceability.

Jan 1, 2011

The following situation was submitted as an ethics case study for inclusion in the Journal. To the best of our knowledge, they are based on actual circumstances encountered in the field. Blowing the Whistle Protecting Confidentiality or Doing the Right Thing? This case centers around a construction job and involves a contractor, subcontractor/blaster, and a farmer/homeowner who lives near the job site. It is essentially a study of professional ethics versus morality, our professional code of conduct versus what is right or wrong.

Jan 1, 2007

By Brad Bockey

Whether you are a driver, blaster, or are in charge of filing, you must recognize the importance associated with DOT-required recordkeeping. As various agencies become intertwined with rules governing the explosives industry, the records we produce must be as accurate as possible. The time is right for reviewing your paperwork process from start to finish.

Jan 1, 2011

By Jane Wright, Brent Blanchard

Question: When it comes to demolition projects, what could be more demanding than asking a blaster to explosively demolish a stubby, heavily-reinforced concrete structure in the heart of a third-world country? Answer: Asking them to fell only half. Such was the charge recently put forth to Controlled Demolition Group (CDG), Yorkshire, UK when they were called to Casablanca, Morocco to provide a stunning demolition effect for the upcoming Universal Pictures film Spy Game, starring Robert Redford and Brad Pitt. Director Tony Scott (True Romance, Enemy of the State) contacted the renowned demolition firm after seeing their work on television and receiving recommendations from explosives manufacturers. The film’s producers then asked the CDG team if they could bring down half of an apartment block as part of a dramatic suicide bomber sequence.

Jan 1, 2002

By William Reisz

In our line of work,like many other professions, there may be times when circumstances or a series of events may arise, contributing toward unacceptable risk. When multiple parties are involved, there will almost inevitably be differences on how best to deal with these situations. Unless approached in an intelligent and these differences may often have the potential for costly and unexpected results.

Jan 1, 2014

By Steve Dillingham

A blast site incident has just occurred. Tensions are high, and, as the blaster, you’re in charge of the crisis at hand. Your mind is reeling, your thoughts frantic. The main areas of concern for you at the scene are to deal with immediate problems...aid the injured, take a head count, assess the damage, call emergency response, contact company headquarters, calm the neighbors, update your customer, and respond to the press on site. You feel as if all the bases have been covered...but, then again, have they? One of the biggest mistakes blasters and their companies can make is not including their Insurance carrier in the critical on-site accident procedures and emergency call list. Unfortunately, many companies believe that they are immune to the perils that can often, within a matter of minutes, create chaos that only happens to someone else.

Jan 1, 2002

By Robert Hopler

Torpedoing Wells. – On the completion of the drilling, or when the production is found to decrease, it is usual to “torpedo” the well to increase the flow. This process was patented in 1862 by Colonel Roberts, who believed, with many others, that the oil was contained in crevices in the rock, which might not have been tapped by the bore-hole. He therefore proposed the use of nitroglycerine, gunpowder, or other explosive, to break up the rock at the bottom of the well, so that these rich “pockets” might be brought into communication with the well.

Jan 1, 2007

By John Horgan, Ethan Marcoux

Explosives have been used to demolish many unsafe structures around the world. However, it is unlikely any demolition job has ever involved destroying buildings already buried 40 feet (12 meters) into the world’s largest ice sheet. That is what happened to the original research station at the geographic South Pole, built back in the 1950s, following a series of discrete explosions between 2011 and 2013.

Jan 1, 2015

By Ricardo Dr. Chavez, Mathieu Lachamp, Rob Dr. Farnfield

Pueblo Viejo is an open pit gold mine in the Dominican Republic which is always looking forward to implement the newest technology in the industry to improve all processes. Focusing on one of the pillars of the department and our company, digitalization, we’ve been looking for the technologies that allow us the automation of data generation, supervision and process innovation. That’s where a new Drill and Blast software takes place, helping to integrate the process from the beginning to end, right after the pattern is designed until it’s blasted, allowing us to track results like vibration, fragmentation, performance, cost and inventory of each blast in a single platform. The software helps engineers to generate back analysis by blast, bench, pit, month and many other ways, in a timely friendly manner. Therefore, we can catch business opportunities and improvement for the drilling and blasting process.

Jan 1, 2019

By Edward P. O'Hern

The importance of the so-called explosives and the increasing extent of their use are evident from the fact that the production in the United States for the year 1910, as shown by the United States Census reports, amounted to the enormous total of approximately 480,000,000 pounds, this being more than double the production of 1905 and more than three and one-half times that of 1900

Jan 1, 2015

By James Stuart

A man died when the primed charge he was holding against his chest exploded. He was doing legitimate explosive work, and he was following all the safety procedures he had been taught. He and his colleagues had done this, thousands of times previously, with no ill effects.

Jan 1, 2007

By Ashley Haslett

A European Directive on Identification & Traceability of explosives came into effect on the 4th of April 2008. This directive is intended to establish a harmonised system for the unique identification and traceability of all packaged explosives, detonators, reels of detonating cord and primers used in civil applications across the European Union. The directive must be adopted into the national legislation of each European Union member state by the 5th of April 2009 with compliance achieved throughout Europe by the 5th of April 2012. The requirements of the Directive apply to all explosives manufactured, used and imported into the European Union from 5th April 2012.

Jan 1, 2010

By Tristan Worsey, Jhon Silva

The paper discusses a limestone quarry case study that looks at change in fragmentation due to using different charge sequences when using the regular rhythmic timing method.

Feb 1, 2020

By August Ferraz Ribeiro, Guilherme Dias Mendona, Paula Henrique Lisboa, José Silvio Corsini

Correct slope adhesion is related to the conformity of the slope’s real geometry to slope planning. It is very important in mining because slope design has economic and safety implications. Slope design conditions can interfere with mining waste and ore proportion. Without a correct wall, the development of the mine can be hindered, which can reduce the amount of ore available. Furthermore, correct slope design reduces the possibility of melting and allows traffic with equipment and people in the mine. However, defining the wall is a more complex work as the characteristics of the rock require the use of blasting techniques. Therefore, Enaex Mining Technical Solutions (EMTS), in partnership with the engineering team at the Chapada Mine, at Lundin Mining, has developed this study in order to increase slope adhesion. The basis of this study is a near-field vibration test, which enables the creation of vibration attenuation law, and a seed wave damage model has allowed the characterization of the rock present at the Chapada Mine. Then, we could compare the model result to the real slope adhesion achieved with the buffer technique used in the mine. Therefore, it was possible to relate the real result to the model result.

Feb 6, 2023

By G. Cavanough, A. Torrance

Emulsions have been developed for over forty years to become the most common water-resistant explosives used in the mining industry. An emulsion is a common commodity, with many examples in our day to day lives of one immiscible liquid dispersed in another. They have varying degrees of stability from a few seconds to years. What makes their application in explosives unique is twofold. They contain a high concentration of salts in the dispersed phase and also have a far larger volume of dispersed phase than continuous phase. The continuous phase contains at least 75% by weight of an oxidizer such as ammonium nitrate dissolved in water. The crystallization point of these solutions is often >60oC which means that the formation of the emulsion has to occur at an elevated temperature. Once the emulsion is cooled, its structure helps to prevent the formation of crystals in an otherwise unstable system. At room temperature there is a considerable potential for the small oxidizer droplets to crystallize which is countered by the strength of the oil layer and also the size of the emulsion droplet. If the emulsion droplet is too large then crystals can form which may lead to rapid deterioration of the emulsion and overall crystallization, accompanied by a temperature rise as the heat of crystallization is released from the emulsion. The size of the emulsion droplet is critical in preventing crystal growth and subsequent droplet coalescence and emulsion break down. One method of examining emulsions and understanding their structure is to use optical microscopy to measure droplet size and also emulsion deterioration from shearing, temperature cycling and when contaminants are introduced, such as detergents, different oil types, coating agents and dust particles. This paper reports on advanced techniques to quickly assess emulsion quality and stability

Jan 1, 2024

By Harry Thompson

In using explosives to blast stumps from the ground in order to prepare it for farming, it is comparatively easy to place the charge under a stump having a semitaproot or a lateral system of rooting by boring or digging a hole in the earth to a point under the center of resistance and deep enough to give the desired effect.1

Jan 1, 2015

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 Joseph Hoang, Nick Reed, Scott Wishart, Michael Lovitt

Marvel Loch Underground forms part of St Barbara Limited’s Southern Cross Operations which is located 360km (224 miles) east of Perth. Southern Cross Operations produces approximately 120,000 ounces of gold each year. Mining occurs in over 8 lodes using a variety of stoping methods including Uphole Benching, Long Hole Open Stoping, and Core and Shell.

Jan 1, 2012

By Tom Paynter

In an underground mining environment, the primary method of firing a blast is using a combination of an electric detonator and a detonating cord to initiate the Nonelectric detonators. This method has been in use since the 1970’s. A firing line is used which can be subjected to damage and the need for constant testing and maintenance.

Jan 1, 2017