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By Antonio S. Aldana Selders

With special designed explosive and a system to lower down a heavy load of Explosives through 8" pipe results are achieved, the stimulation of sulphur production takes place. Well # 18-1063 at 515 meters below ground is loaded with 802 units of explosives with total weight of 1820 kilos to fill up the column of 93 meters of limestone & sulphur strata.

Jan 1, 1995

By D D. Garg, D A. Wasson

Open pit blasting in India uses two types of explosives. First there are bulk explosives for wet and dry holes, and there are packaged explosives. The Indian open pit coal mining is projected to use 190 thousand metric tons of explosives in 1995. This volume is projected to grow for the next ten years, whereas the underground coal mining will hold fairly constant.

Jan 1, 1995

By Ulrich Leiste, David M. Fox

This paper presents the results from small scale testing aimed at measuring the loads on a rigid target due to the detonation of a buried mine. The aim of this research is to find how the impulse delivered to the target varies as the air filled void volume fraction within the soil changes.

Jan 1, 2013

By D Schneider, H Elliott

The advantages and disadvantages of using inclined boreholes in blasting has been under discussion for a long time. Some recognized disadvantages are that drilling costs, both operating and capital costs, are higher for inclined holes than for vertical ones, and that drilling accuracy is more difficult to maintain. People who have used angled holes in practice, on the other hand, have claimed that the quality of blast results was improved. In fact, their popularity has increased, especially in Australia.

Jan 1, 1988

By Ethan Steward, Kyle Perry

Blast resistant structural design continues to be a research area of major concern for governments around the world due to explosive threats from both state and non-state actors. Glass and aluminum curtain wall systems are commonly used to clad the exterior of government and commercial structures, allowing light into the building, regulating the interior environment, and providing an aesthetically pleasing exterior. These systems are likely to fail when exposed to sudden, high-pressure events such as the purposeful or accidental detonation of explosives. Engineers have designed blast resistant curtain walls and structural elements to reduce the likelihood and severity of failure, but the design tools and testing mechanisms commonly used in the process may not accurately model or simulate actual blast conditions at all ranges. In blast resistant structural design, the origin of a shock wave is typically assumed to be in the far-field, creating a wave that is nearly planar and parallel to at least one face of the target. Shock is applied evenly and immediately across the entire impacted surface. However, the source of real-life blasts is often very close to the target structure, and the assumption of far-field planar shock does not always apply. Mid-field blasts exhibit qualities different from those assumed about far-field shocks, specifically a hemispherical shock that produces different peak pressures, impulse curves, oblique reflections, and Mach stems across a target. This paper will examine mid-field shock effects from scaled distances of 2.5 to 4 13 (6.3 to 10.1 13) on a tall, scaled target by measuring reflected and incident pressure, impulse, and shock velocity across the target. Results will be compared to theoretical blast parameter equations and empirical data used by the industry. Possible effects of mid-field blasts on structures and further research ideas will be suggested.

Jan 21, 2025

By John M. Bolger, Keith E. McMaster

Excessive salt fines are undesirable in underground salt mining as they are considered a costly waste byproduct. This paper describes an extensive explosive application program conducted at The Canadian Salt Company Ltd, located in Pugwash, Nova Scotia, Canada. The prime objective of the program was to reduce the quantity of fines generated from this company’s underground production blasts. The program was known as the “The Fines Reduction Program”.

Jan 1, 1996

By Leslie Taylor, R. Reed Skagga, William Gault

The ultimate aim of our overall task, of which the effort described in this paper is a part, is to be able to model the impulsive output of buried charges and the response of targets of interest. It is not practical or cost-effective to determine the response of all targets of interest to buried charges of all sizes by testing them. In order to have confidence in our models, however, they must be validated by a modest number of tests. A critical element in modeling the response of a target is the ability to model the loading function. The load a buried charge applies to a target above it when the charge detonates can be characterized in terms of the vertical impulse. The vertical impulse is a function of the size of the charge, its depth of burial, and the properties of the soil in which it is buried. The primary objective of the effort described in this paper is to determine the load a known charge places on a non-responding target so the data can be used to validate our models.

Jan 1, 2005

By Edward Jr Walter

This paper discusses the problems that arise in the process of developing adequate explosives noise legislation. Case histories are used to illustrate how and where these problems arise and the course of action followed in overcoming them. It is imperative that those concerned keep informed as to possible legislation and be prepared to present solid facts that will insure fair and reasonable controls.

Jan 1, 1975

By Mark S. Stagg, Stephen A. Rholl

As part of its research program to evaluate efficient design criteria for improved blast fragmentation, the Bureau of Mines has developed two computer programs to facilitate data analysis. Results of these two programs are used to better understand the fundamental parameters of blasting for surface mine rock fragmentation.

Jan 1, 1990

By O Omidi

Selection of delay times to optimize fragmentation has been a controversial topic among researchers and blasting practitioners. This paper reviews previous experimental information and presents the results of new tests conducted in small blocks constructed using a commercial grout. The effect of the delay on the average fragment size, coarse fragmentation and uniformity of fragmentation is discussed. Fragmentation was coarser at extremely short or extremely long delays, while a fairly constant average size was obtained at a variety of intermediate delays. Uniformity, defined as the slope of the fragmentation distribution through the average fragment size, was poor at short and very long delays and relatively constant at the intermediate delays. Some tests attempted to minimize the effect of gas penetration by lining the boreholes with copper tubes. When this was the case average fragmentation changed marginally, while uniformity was significantly affected by delay and was typically smaller than in the unlined tests.

Jan 1, 2014

By Mark S. Stagg, Stephen A. Rholl

The Bureau of Mines is studying blast delay timing influences on rock fragmentation in a series of tests that started in 3-ft concrete blocks, progressed to 45in-bench reduced-scale tests in massive dolomite, and has now included 22-ft-bench full-scale tests in a thin-to-thick horizontally bedded dolomite. This paper discusses the full-scale test results and how they compared to the concrete block and reduced-scale studies.

Jan 1, 1988

By Bill Rose, Alan Foster

This paper will outline blasting as undertaken at the Flour Mill project in the Georgetown area of Washington, D.C. It will discuss the vibration and blasting problems found in blasting in high risk and highly populated areas, and the day to day methods used to minimize damage potential and still maintain adequate fragmentation.

Jan 1, 1979

By Winston Wilches B., Scott Scovira

This paper discusses recent changes to the emulsion blend blasting agent used at the Drummond Pribbenow Mine in Colombia, one of the world’s largest open pit coal mines, and the resulting improvements in rock breakage and excavator productivity. Based on field evaluations, the use of High Density Ammonium Nitrate (HDAN) can be effectively implemented in an emulsion blend blasting agent, yielding excellent results in terms of energy release, shelf life and velocity of detonation (VOD). Field evaluations showed that formulations using HDAN exceed the performance of the actual 50%/50% emulsion/ANFO blend using Porous Prill Ammonium Nitrate (PPAN). PPAN is conventionally used for emulsion blend manufacturing, with physical characteristics to facilitate sensitivity during the detonation process.

Jan 1, 2014

By Shazad Hosein, Rob Farnfield, Bill Birch, Liam Bermingham

The propagation of a shock wave through air as a result of quarry blasting consists only of one type of wave, the compression wave. This is in marked contrast to seismic waves where a number of different types of wave are generated by the one blasting event. Even so the interaction of the burn time of a single hole and the resulting air overpressure is still too complicated to be able to be accurately modelled from first principles. It is considered that the best way forward is to monitor an individual single hole to obtain a signature wave form that has resulted from this complex interaction. Once this wave form is known, the variation in geometry of a mutli-hole blast and the timings of the successive detonations can be modelled to give a sufficient degree of accuracy to recreate the likely magnitude, duration and wave form of a multi-hole quarry type blast. This can then be directly compared with actual air overpressure wave forms from quarry blast to verify the model.

Jan 1, 2012

By Rowland Jones

This type of quarrying is very much different from that of established quarries in developed countries, demanding somewhat unorthodox techniques to produce the variety of materials required. The demands on the resourcefulness of-the quarrymaster can be very testing, and produces quite a different breed of individual than what is normally met in managerial status in quarries of developed nations.

Jan 1, 1977

By K. Ram Chandar, Vedala Rama Sastry

Fragmentation and muck pile profile together play an important role in optimizing the excavation costs for given geo-mining conditions. Initiation system is one of the vital parameters influencing the fragmentation and muck pile throw (profile). An attempt is made through this paper to study the characteristics of muck pile produced in addition to fragmentation. Two new parameters namely “throwburden ratio” and “muck pile ratio” are proposed for assessing fragmentation and movement of material. Field investigations were carried out in a limestone mine in southern India with shock tube and detonating cord initiation, using four initiation patterns, keeping other parameters like burden, spacing,delay timing etc. same.

Jan 1, 2008

By Daniel Castelo, Ben Potter

This paper will discuss the most efficient and effective way to use shape charges when considering standoff distances and the amount of an explosive to be used. For each shape charge test that was performed, a one inch diameter copper liner of 90o was used. Different standoffs for each shape charge were tested to see which one would penetrate the deepest into rolled homogenous armor steel (RHC 44). It was determined that a standoff of three cone diameters provides the deepest penetration. In addition to testing for optimal standoff distances, the effects of overfilling as well as under filling a shape charge with explosive was tested against a shape charge with the bare minimum amount of explosive for correct detonation. These “fill” tests were all performed at a standoff of three cone diameters. Overfilling has little to no effect towards penetrating deeper into a target while under filling a shape charge has an effect of shorter penetration. C-4 explosive was the main explosive for all shape charges.

Jan 1, 2011

By Manuel Calderón

Chile is responsible for 30% of the global copper production; the world ́s largest. However, significant challenges are faced in this industry; declining grades (1.13% in 2002 to 0.61% in 2015), high cost of energy, scarcity of water, and environmental concerns. Mining trends suggest the future of the industry will be focused in the underground space, specifically due to the depletion of economically viable surface mineral deposits. For example, the largest block cave mineat Codelco ́s Chuquicamata mine is expected to reduce energy costs by 50% and dust emissions by 97%compared to the open cut mine. To access these underground deposits, critical infrastructure is required; horizontal tunnel developments, extraction levels, vertical raises, and ore passes with the on-time delivery of the highest quality outcomes being a requisite for successful project delivery (Lift 1 of 3 at Chuquicamata Underground has over 1000drawbells).One aspect that makes this scenario even more challenging for deeper underground operations is the increased risk profile (people, equipment, and geotechnical) that forms part of the general environment. Furthermore geotechnical risks should be considered and they include rock burst and windblast. The safe interaction with this environment must be sustainable throughout the full life of the project. This paper presents the Enaex group approach to addressing the blasting challenges and outlines the solutions created. Aspects such as rock mass damage occurrence as a function of blast vibration frequency content has been studied, as well as the development of blasting methodologies for guaranteeing the full 100% extraction of all infrastructure blasts, including the all-important draw bell volumes. The development of such infrastructure volumes in one single event using electronic detonators and the associated achievement of ambitious productivity goals, are described as a critical part of the successful construction of one of the most ambitious UG projects currently present on the world.

By Mark Bosse

This is a paper demonstrating the use of a fixed wire and trolley system to deliver 2 or 5 lb cast primers (with 2 meter cap/fuse assemblies) deep into avalanche terrain. This avalanche terrain is mitigated using explosives prior to being opened to guests.

Feb 1, 2020

By J P. Tidman, I J. Kirby, G H. Harries

The SABREX computer model is based on the fact that both shock waves and gas pressure are important in describing a blast. The treatment of explosive-rock interactions includes the influence of non-ideal detonation to make use of recent advances in that field. Details of the blast layout are defined from a comprehensive list of conditions the blaster can control (drill pattern, charging and hook-up). The program gives practical and graphic information about fragmentation, muckpile, damage and costs.

Jan 1, 1987