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By Calvin Konya, Theodore R. Myers, Robert Lundquist

The design of a single, large mass blast using ring drilling may take two to three months. This time requirement inhibits the evaluation of multiple designs. It also reduces the flexibility to redesign a blast when a parameter affecting the blast changes. Manual preparation exposes the design of a ring blast to a greater probability of human error. The use of Computer Aided Design (CAD) can help to overcome the shortcomings of manual design preparation. High speed electronic calculation, as well as programming, allow for many designs to be considered before blasting. Parametric programming allows single or multiple parameter changes to be introduced into an existing design, such as changes in drilling equipment, variations in ore density or changes in explosive. Exposure to human error is reduced by programming that performs calculations and produces graphical displays for review by the designing engineer. The goal of achieving desirable fragmentation for the minimum cost, when using ring blasting, is obtainable using blasting design techniques and CAD. Multiple designs can quickly be generated and costed, producing cost curves that indicate an optimum design with respect to cost.

Jan 1, 1990

By B Mohanty, R Deshaies

Initiation of small diameter explosives by sympathetic shock pressure in water has been investigated under controlled laboratory conditions. Changes either in the geometry of the donor explosive or its point of initiation can alter the essential characteristics (amplitude and duration) of the resulting shock pressure pulse. The pressure signatures from both spherical and cylindrical explosives donors have been studied, in water as well as in various explosive matrices. This paper summarizes the investigations carried out with both 'primed' and 'non-primed' slurry and emulsion explosive matrices with various types of voids. These measurements serve the basis for predicting distances in water for sympathetic initiation for both spherical and linear charges. It is shown that the explosive-detonator system in combination has a far greater probability of initiation due to sympathetic shock pressure than either the explosive or the detonator alone. Various explosive matrices with air bubbles and glass microballoons have been examined and the differing sensitivities to shock pressure explained on the basis of these measurements. It is also concluded that explosives containing air bubbles instead of microballoons would be significantly more prone to sympathetic initiation.

Jan 1, 1992

By Quian Liu

Since the establishment of the CANMET Experimental Mine in Val d'Or, Quebec in 1991, research activities in rock fragmentation have been carried out not only in the underground laboratory but also in production mines in the north-west Quebec region. Among the instruments available for rock fragmentation, the Kodak EktaPro 1000 Motion Analyzer (also called the high speed video system) has been one of the most useful tools for monitoring blasts in both underground and open pit. This system is capable of recording events at rates from 50 to 12,000 frames per second (fps). The buffer memory has a capacity of storing 2050 images. To use this system in the underground, a steel box was made with a bullet-proof glass in the front to protect the camera. The processing and recording equipment are placed in an aluminum case which can be located about 30 m away from the camera via an extension cable. For each blast monitored, high frequency geophones and accelerometers were used to monitor ground vibrations and give a timing reference of the explosive detonations to correlate with the observation of the captured images.

Jan 1, 1994

By Paul Worsey, Attila Szucs, Mark F. C. Schmidt

The use of water stemming with small explosive charges has been successfully developed at the University of Missouri-Rolla. Further study has been started to explore additional applications and uses for water stemming. Work has been focused in the areas of rock excavation and perimeter blasting techniques. This ongoing work is being conducted internally as graduate and undergraduate level research. A paper describing the general technique for use with boulder fragmentation was published in last year’s proceedings. The excavation work took place in the form of both small bench and trench shots while pre-split and trim shots comprised the perimeter-blasting portion. The excavation work was located in both the Roubidoux sandstone formation and the Jefferson City dolomite formation. Hole diameters ranged in size from 1.5” to 3” diameter and powder factors ranged from l/l 0 to l/3 of the conventional charge weight. The water was used to both couple the explosive charge with the surrounding borehole, as well as stemming. No other stemming material or products were used. The method of using water stemming in perimeter blasting was found to work well. However, when used for excavation purposes, adequate rock movement was not obtained. The rock was often split, but not fragmented. The airblast was surprisingly low, but the ground vibrations were excessive. This is not the case with trim shots, and therefore this method appears ideal for splitting purposes, especially in areas where people do not like to stem the tops of the holes, and where airblast and vibrations are of concern. Water coupling dramatically increases splitting and fracturing. However, fragmentation is not only fracturing but also the movement and swelling of the material. As the charge weights are reduced with this method, sufficient gas volume is not created to cause this necessary movement and swell, which is critical in rock excavation. This explains why its successful application was limited to perimeter blasting applications.

Jan 1, 2000

In the March/April 2006 issue of the Journal, we published an ethical dilemma called “Blowing the Whistle.” We received many interesting responses to the article as requested. Some of the responses are printed here. We’ve also included “Blowing the Whistle” again in this issue as a refresher on page 37. Dear Editor, It is in my own personal belief that it would be extremely important if I were the blaster to take the following steps. 1. Hold an immediate emergency meeting with the contractor to convince them to stop work at this point.2. This meeting would need to be held with all powers that be in this construction company. This helps eliminate the hearsay (excluding the farmer). 3. Explain the entire situation to the contractors as it has been presented to the blaster by the farmer. 4. Recommend calling in an engineering or geological firm with the expertise to investigate this matter immediately, and take all immediate action based on findings. 5. Follow up with farmer allow him to speak, (a.k.a. vent) and assure him proper steps are being taken to come to resolve this matter. 6. Be a good listener, and communicator with the farmer while investigation is being conducted. 7. Should the contractor not want, or take any of these recommendations, the blaster himself and his company should question even working for this company ever again. This in itself would not be the class of people we would want to be associated with EVER.

Jan 1, 2007

By Thierry Bernard

New technology to automatically design a blast based on autonomous drone. The process of flying a drone, calculating the 3D cloud of points, generating the critical face profiles and placing holes automatically according to burden specification becomes fully automatic. A nice time saving with more efficiency

Feb 1, 2020

By Dr. Anurag Agrawal, Steve Franklin, Clint Zimmerman, Elijah Williams

In a time when data has become a highly valued commodity within many mining and quarry operations, managing large amounts of current and historical information can be difficult. If not managed properly, trying to leverage the data to make informed operational decisions promotes another challenge. Geographic Information System (GIS) is an environment that uses computers and software to create, manage, analyze, and map all types of data. Currently, the mining industry is faced with a challenge to produce the demanded critical metals and minerals that drive our economies. GIS is leveraged in many large mining industries today to help drive decisions, save cost and plan for future operations. Specifically in the Drilling, Blasting and Quarrying industries, data is being captured at many different levels, whether it is a subsurface geological, blast performance, quarry surveys, loading and hauling, or crushing performance. Pen and paper logs and reports compiled lack the dimension that GIS can bring for extracting value from real-time or historical data. GIS connects data to maps, integrating location data with all types of descriptive information. Paired with Artificial Intelligence, additional analytical layers can be built on platforms to extract data and automate workflows. Having the ability to encompass several forms of collected data to drive operational decisions can bring huge savings to the bottom-line. This paper will dive into the areas where GIS data can drive value into operations by assisting in the management and analysis of the types of data being captured, specifically with Drill and Blast. Whether it is tracking haul road conditions, monitoring locations of equipment, environmental conditions, quantifying blast performance or developing a quarry plan based on geological models. GIS can collectively encompass all of this data to bring tremendous value to the operations, improving safety, efficiency and production.

Jan 21, 2025

By Ravi Sahu, Kris Jeremiah

This paper aims to study the benefits of using Post Processed Kinematics(PPK) surveying methodology combined with Drone photogrammetry to achieve highly precise positioning (X, Y, Z) of drill holes based on the drill pattern and to highlight innovative workflow of transmitting the drill plan to smart drills for accurate drilling.

Feb 1, 2020

By Michael David Wilkins, Paul N. Worsey

Little research has been published on stemming blast holes, particularly what happens during the process. Previous work has concentrated on the performance of the inert material to find the best way to seal the hole and retain the explosive energy, at the exclusion of determining what happens during the loading and stemming process.

Jan 1, 1998

By R D. Skaggs

A good blast is dependent on a well engineered design. However, a good design's performance depends on the control of the drilling and loading of the blast holes. The key stone to good blasting is the drilling of straight holes of the correct orientation in the required positions.

Jan 1, 1991

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 William D. Hissem

The purpose of this paper is to advise people about the methods, use, and possible applications of current "personal computer" hardware and software with regard to the economic cost analysis of percussion drilling equipment. The material content and orientation of this paper is toward those people who have just begun "PC" (personal computer) operations, and (or) those who are considering their use.

Jan 1, 1986

By Zhang Shixun, Wang Xuguang, Zhong Yinting

The Mongol-Russian Joint Mining and Processing Cu-Mo Corporation Erdenet signed a contract with BGRIMM for building a plant to produce 10,000 t/y multitype emulsion explosives by using BGRIMM emulsion explosives manufacturing technology. In order to ensure the realization this contract, we have done a series of studies on the design of technological process and the selection, layout of the production equipment, and made a success.

Jan 1, 1997

By Hans Florin

This paper describes the modification of a nonelectric detonator which is ignited by a signal tubing. The heart of the new detonator lies in a so-called ignition transmitting element. The construction of the transmitting element is such that the detonator remains closed even after the signal tube has functioned. Due to the sealing of the delay element, this nonelectric detonator achieves the same accurate delay timing as high tech delay electric detonators and will not fail due to a sudden pressure loss.

Jan 1, 1988

By Phil N. Bradbury

"During a routine belt tightening of all cost centers, the management at the Martin County Coal Surface Mines, located in Martin County Kentucky felt that a thorough investigation of the drilling and blasting program could possibly pinpoint areas where the cost could be cut without sacrificing production. Upon close inspection of the drill benches it was noted that the actual layout of burden,spacing and stemming varied a bit from the actual blast design that the management had outlined for the blasters. This paper will outline the method of reducing the drilling and blasting cost at the Martin County Coal Operation."

Jan 1, 1986

By Andrew Drake, Mark Burchard, Peter Bellairs

The Astec Bluerock Quarry is excavating an extremely difficult to blast rock type due to its highly variable jointing density that leads to excessive oversize. A drill and blast benchmarking exercise led to eight recommendations to minimise this problem. Quarry personnel instigated a continuous improvement blasting program, that has implemented six out of eight recommendations, resulting in a large reduction in the oversize and increased crusher throughputs for a marginal 7% increase in drill and blast costs. Unit costs have reduced by an estimated 10%.

Jan 1, 1998

By Agus Setiabudi

East Pit Wira II Project in South Kalimantan, Indonesia with a radius of <500 meters (1,640 ft) from residential has about 454,168 tonnes of coal reserves, with a total remaining reserves of 3,369,383 tonnes (topography per end of June 2011). Thus, reserves may be lost as much as 13.48%. Therefore, it is needed to determine safe blasting technique which meets the Indonesian National Standards (SNI) No. 7571:2012 of vibration threshold, the maximum vibration of 3 mm/s (0.118 in/s) and air blast of 120 dB.

Jan 1, 2014

By J J. Mullay, G W. Anderson, C J. McFinley, J F. VanNorman, C J. Kefer

Previous work has shown that testing of precompression effects conducted on a small scale under simulated field conditions in actual rock provides a reasonable model for the evaluation of explosives and initiators under the adverse conditions encountered in production blasting. Using this methodology can result in greater understanding of the phenomena as well as the ability to predict performance. This effort has been extended to evaluate various parameters not previously studied in a controlled fashion. The present paper describes the use of this technique to study the effects of delay timing on precompression effects. Intervals from 25 to 150 milliseconds are included in the study. Both VOD measurements and damage estimates are utilized in the evaluation. The results demonstrate that timing delay between holes is quite important in determining the overall effectiveness of a blasting program.

Jan 1, 1994

By P D. Kasbanis, Lyall Workman

The energy output of an explosive is typically calculated using an equation of state and computer applications. Results are reported as weight and bulk strength, either in absolute terms or relative to ANFO. The effect of the equation of state selected and the assumptions regarding the energy calculation are considered and interpreted for the purpose of blast design. It appears that variations in the heat of detonation which result from the selection of the equation of state and parameters associated with it are not sufficient to significantly affect blast patterns, explosive consumption and costs. However variations stemming from the use of "available energy" associated with a cut-off pressure are significant, suggesting in many cases large pattern expansions. The validity of the various approaches is discussed and blast design results based on the energy calculated by the different approaches are presented and evaluated.

Jan 1, 1996

By Steven V. Crum, Willard E. Pierce

Concern has been raised about the adequacy of current regulatory guidelines designed to protect homes from unwanted blast damage due to low frequency ground vibrations; in particular those with predominant frequencies below 6 Hz. This report summarizes and updates the preliminary results of a continuing Bureau of Mines investigation which will be completed later in 1995. Four structures at four different surface coal mines have been studied by examining their response to ground vibrations created from overburden blasting. House response to ground vibrations with dominant frequencies down to about 3 Hz were recorded. Many of the blasts produced ground vibrations with peak amplitudes above expected crack-producing thresholds. Response motions were compared to those predicted by theoretical single degree of-freedom response models.

Jan 1, 1995