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By Karl Kure, Anders M. Heltzen

Mixtures of prilled ANFO and 0,5 - 3 mm polystyrene balls are interesting substitutes to the tube charges or other types of reduced explosives or detonation fuses. Experiments have shown detonation ability even of a mixture of 95% bolt polystyrene balls and 5% ANFO. The gas and shock energy in the mixtures decrease proportional with the content of polystyrene. The detonation velocity shows higher values than expected for mixtures with more than 50% (vol.) ANFO.

Jan 1, 1980

By Lee W. Saperstien

Section 709 of Public Law 95-87, "Surface Mining Control and Reclamation Act of 1977," requests the National Academy of Sciences to determine if the standards of the act are applicable to minerals other than coal. The Academy has established the Committee on Surface Mining and Reclamation to respond to this charge. The committee is, itself, organized to be responsive to the varieties of minerals, environments, mining systems, and locations that are representative of U.S. mining systems. It is not the charge of the committee to write trial legislation, but to indicate whether or not technology, extant or proposed, is available to meet the standards of the law, and at what cost. It is within this set of conditions that the committee will examine blasting.

Jan 1, 1979

By Andreas Bienz

The safety of persons from accidental explosions and fires during manufacture, storage, transport etc. of explosives, pyrotechnics, propellants, firework and ammunition is most commonly assessed according to prescriptive rule-based approach: Safety is given when all requirements which are listed in numerous regulations and directives (such as e.g. safety distances, limited quantities, protective installations etc.) are complied with. Such a deterministic prescriptive rule-based approach is quite easy to apply but has got disadvantages, however: The actual state of safety in a specific case is not explicitly and quantitatively expressed, and it is not distinguished between the endangered individuals and the whole group. As a result, the effects of the safety measures cannot be measured. This is why uneconomical and in the worst case useless safety precautions cannot be avoided. In addition, waivers are difficult to negotiate, meaningful and sound arguments for pro and con being lacking.

Jan 1, 2007

By Thierry Bernard

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts

Feb 1, 2020

By D. Preece

The mining and oil industry employs techniques such as geologic mapping, core drilling and electromagnetic and potential field techniques to explore for new deposits. Since new discoveries of major near-surface ore bodies are becoming progressively rare and since traditional exploration methods are unable to resolve ore bodies deeper than about 500m, high-resolution seismic reflection techniques show great potential for exploration to much greater depths down to almost 3km.

Jan 1, 2011

By Murray B. Lytle

The Fording River Operations of Fording Coal Ltd. in southeastern British Columbia is producing 45 million long tons of clean metallurgical coal for shipment to the Japanese steel industry on a 15 year contract. The mine employs conventional truck/shovel operations as well as a walking dragline to mine coal in two mining areas. The coal is processed by conventional means to produce 3.0 million long tons per year of medium volatile coking coal.

Jan 1, 1978

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 E. McCullough, D. Preece, M. Ortel

The mining and oil industries employ techniques such as geologic mapping, core drilling and electromagnetic field techniques to explore for new deposits. New discoveries of major near-surface ore bodies are becoming progressively rare and traditional exploration methods are unable to resolve ore bodies deeper than about 500 m (1640.4 ft). Consequently high-resolution seismic reflection techniques show great potential for exploration to much greater depths down to almost 3 km (1.9 mi).

Jan 1, 2013

By Gary Cavanough

The spontaneous exothermic reaction of ammonium nitrate explosives with sulphide-containing rocks, commonly referred to as reactive ground, is a site-specific condition that can lead to spontaneous detonations. Mine sites typically carry out regular assessment of ground for reactivity. In Australia, reactive ground testing is conducted according to the Australasian Explosives Industry Safety Group (AEISG) Code of Practice. This paper presents a new method to assess reactive ground. The new method can be completed on the mine site or in the laboratory. The new method allows samples to be tested in hours not weeks, as required when using the method prescribed in the AEISG Code of Practice. The new method also provides an explanation of why ground is reactive or not reactive, Whereas the AEISG Code of Practice provides a reactive, not reactive or marginal results with no understanding of reason for these results. Case studies on the use of weathering agents, pH, sulphide content and carbonate content will be reported. These case studies identify instances where the testing as per the AEISG Code of Practice provides false positive and false negative results. A false positive result will require the use of inhibited products when they are not actually required which increases costs and reduces productivity due to the need to used multiple explosive products. A false negative result increases the risk of an unplanned initiation of a blast hole.

Feb 6, 2023

By Dr. Anurag Agrawal, Fathur Rozaq, Nella Lubis, Relinda Sanistya, Herry Saputra, Rudolf Sitorus

In mining operations, basic drone applications such as pre- and post-blast photo comparisons, blast video recordings, and sample-based fragmentation analysis are often used to assess blast performance. However, these methods lack the depth needed for comprehensive evaluations, leading to suboptimal results. This study explores the innovative integration of drone mapping technology with artificial intelligence (AI) at the Martabe Gold Mine in North Sumatra Province, Indonesia, to address these limitations. High-resolution drones and ground control points (GCPs) are utilized to create detailed orthomosaic maps, and advanced AI algorithms are applied to enhance the accuracy of blast performance insights. Field experiments reveal substantial improvements in comprehensive blast performance evaluations through this integrated approach. Enhancements include improved pre- and post-blast evaluations, AI collar detection, fragmentation size measurements, heave muckpile profiles, cast material measurements, floor prediction models, and muck pile topography volume, which is vital for ore tonnage predictions. Notably, this method achieves an average volume accuracy of 1% compared to light detection and ranging (LiDAR) technology. While LiDAR is known for its precision, the drone-based method offers a highly accurate, cost-effective, and user-friendly alternative suitable for mining applications. Despite LiDAR's superior precision, our approach provides a practical solution due to its accessibility and ease of implementation. In conclusion, the integration of advanced drone mapping and AI technologies has the potential to revolutionize blasting operations. By addressing the limitations of previous methods, this approach meets the evolving needs of the mining industry and sets new standards for accuracy and effectiveness in blast performance assessment. The combination of high-spectral drone images and AI-based software analysis demonstrated nearly 99% accuracy in ore tonnage prediction models compared to LiDAR, showcasing its promising capabilities.

Jan 21, 2025

By Wang Zhong Qian, Liu Hui

The paper proposed a fractal and damage model for rock-breaking by blasting, which assumed that the process of rock-breaking results from intrincent fractal development and the accumulation of damage. Remarkably, the process is of fracture character. Based on the model, a computer program is compiled to calculate the 3-dimension damage distribution in blasting crater. Trial results agree well with the predicted results, showing the model set up in the paper is sound.

Jan 1, 1997

By Thomas P. Mahoney

Phelps Dodge Corporation's Tyrone Mine is a large open pit copper operation located in the southwestern corner of New Mexico. The Tyrone concentrator processes approximately 50,000 tons per day of copper ore. The waste ratio for this operation is 3:1; e.g., for every one ton of ore mined, three tons of waste material are also removed. This results in a mining rate of about 200,000 tons per day.

Jan 1, 1986

By R L. Mayville

The author explains why the strategic location and important limestone reserves at Chattanooga Quarry led to a decision to extend operating life by continued benching down to lower levels. He discusses the steps taken to accomplish this objective. These include relocation of the primary crusher from the second level to the fourth level, pre-testing of explosives designs and powder factors, control of a substantial water problem, and computer monitoring of stone production costs.

Jan 1, 1984

By Thomas E. Ricketts

Occidental Oil Shale Inc. has spent the last eight years at its Logan Wash. mine near DeBeque, Colorado, developing its modified in-situ oil shale process for obtaining oil from oil shale. Modified in-situ technology involves large underground chambers, or retorts, which are formed by mining out a minimal volume of rock to allow explosive expansion of the surrounding rock into tile mined void volumes. The resulting rubblized retort volume must contain a fairly uniform particle size distribution and void distribution to permit maximum oil recovery during subsequent in-situ processing operations. The more uniform the rubblized volume of particles, the more oil recovery obtained during processing. The processing involves first igniting the top of the retort and then. injecting air into the top of the retort to drive the combustion front downward through the entire rubblized volume. The oil is continuously collected at the bottom of the retort during the processing.

Jan 1, 1981

By G. Walsh, M. T. Wild

In this paper the performance effects of linear shaped charges will be discussed. Different sized charges were tested and reviewed based on their performance used with a typical detonation method vs. detonation with a line wave generator. The goal of the project was to determine if the linear shaped charge had better performance with an ideally linear wave moving through it, verses a swept wave that is currently used. A line wave generator is a flexible sheet explosive formed into a triangular shape with holes placed in strategic places to cause a detonation wave to become linear across the width of the triangle. A standard linear shape charge with a detonator in the side of the charge was be detonated against a witness plate to get a standard depth of penetration. A second standard linear shape charge with a detonator connected to the top of a line wave generator, the line wave generator placed on top of the linear shape charge, was be detonated against a witness plate to get a comparison depth of penetration. All charges had a standoff 1.5 times the width of the cavity, allowing the data to be compared to the control charge. Computer modeling was intended to be used to predict the results from testing these designs in the field. The actual results were compared among themselves.

Jan 1, 2011

Dear All, I am looking for information about vibrations and effects on fish in pools. A tunnel blast is planned to be carried out as close as 300 meters to a freshwater fish growing plant. What is the vibration criteria for fishes in pools? Your comments will be highly appreciated.

Jan 1, 2012

By Raphael Trousselle, William Reisz

The blasting industry is now well into its second decade of commercial use of electronic detonators. As an increasing number of blasters are introduced to the technology, the benefits are becoming more widely monitored and accepted in many surface blasting operations. However, their use in underground applications is not yet as widely established. This is primarily due to the distinct cost dynamics and processes associated with underground lasting.

Jan 1, 2012

By Robert Hopler

INTRODUCTION NOT so very many years ago the farm was about the last place where one would expect to find up-to-date mechanical appliances. Steam, explosives, electricity—the factors which have made the world in general, and America in particular, what it is today— were indispensable for the railroad and the steamboat, the factory and the mine, but the farmer’s work was generally run on a comparatively small scale, and was mostly done by the muscles of men or draft animals. Today, however, the farmer as well as the manufacturer, the contractor and the miner, fully appreciate the value of labor-saving devices. Every up-to date farm, large or small, has modem machinery that tends to reduce the cost of production or to improve farm products.

Jan 1, 2011

By Robert Hopler

In part one we discussed a Chinese seismoscope allegedly invented and used in the year 136 (or 132, depending on the source). Interestingly, historical references to the measurement of earth movements then seem to be nonexistent until up into the 1700’s. There could be two explanations for this hiatus: first, that there were no earthquakes in the world for 1600 years, or, second, the “Dark Ages” really did exist, where intellectual inquiry and all sorts of learning came to a halt. Of course there were earthquakes, so the explanation for the lack of a record of invention is the reality of the Dark Ages. explained is the fact that the Dark Ages ended in about A.D. 1000, but that is beyond the scope of this story.

Jan 1, 2006

By John T. Aler

The U.S. Bureau of Mines has been studying the problem of why explosives detonate weakly or misfire during blasting in underground coal mines. Cross-borehole shock wave interaction has been identified as a predominant mechanism causing explosives to function improperly (1)(Underline numbers in parenthesis refer to items in the list of references at the end of this report.). Cross-borehole shock wave interaction can be simulated in a laboratory setting, making possible the replication of tests in sufficient numbers to understand and quantify some of its effects on permissible explosives (2). The work presented here investigates the capacity of explosives to partially recover from the desensitizing influence of the shock wave. The recovery trend of different explosives can indicate optimum blasting patterns useful for minimizing borehole charge malfunctions.

Jan 1, 1991