Search Documents

By F M. Dantini, P Berry

An experimental investigation on the trend of cratering induced by explosives placed on rock masses was carried out. By using various types of explosives and rocks having different geomechanical parameters, it was possible to evaluate the influence of the explosive-rock coupling. Furthermore, the importance of the parameters defining the rock and the explosive for the absorption of energy induced in the rock mass, is pointed out.

Jan 1, 1981

By Lon Santis

In 1923, Ralph Assheton compiled a report for the Institute of Makers of Explosives (IME) on accidental explosions in manufacturing plants. The report chronicles the type and amount of explosive involved in the event and the effects and distances to nearby buildings and workers for over 100 events from 1880 to 1916. Apparently, this report was never published but served as the origin of the IME’s first intra-plant distance table published in Pamphlet No. 3 in 1926. The effort was a parallel effort to the IME’s development of the American Table of Distances. The intra-plant distance table has never been changed by the IME and follows the US Department of Defense (DoD) standard very closely. This paper freshly compiles the data from the 1923 report and analyzes it with modern methods not generally available in 1923. Interestingly, the analysis indicates that the original intra-plant distance tables were established primarily to protect workers from serious injury and that preventing propagation was a side benefit. The data shows that a strong relationship exists between the probability of injury and the traditional K-factor. The data indicate that people in the open are better protected than those inside structures and that barricades reduce risk close to an event. Individuals at the intra-plant distance had a 95 percent chance of receiving no worse than a minor injury. A comparison of the data to explosive event consequence models indicate the models are overly conservative in regards to risk inside inhabited building distances.

Jan 1, 2010

By Adrian J. Moore, Alan B. Richards

Responsible blasting requires that rock throw be controlled to ensure that no danger will result to people and property. This paper describes the development and testing of empirical field calibrated formulae that can be used to evaluate rock throw, provide an early warning of when reduced burden will endanger people and property, and prevent flyrock incidents. Inputs to the formulae are charge mass, burden or stemming height, and a site constant that lies within a general range that can be tightened by site calibration. The output is the distance that rock will be thrown, and this ‘design your own flyrock’ quantification can be used to establish both safe clearance distances, and the critical range of burdens and stemming heights where the situation changes rapidly from safe to hazardous. Examples are given of the use of the model to control flyrock in open-pit mining and quarry operations, in situations which are controlled by both burden and stemming height.

Jan 1, 2004

By Luis Huaroc, Augusto Sotomayor, Erick Rodriguez, Paulo Fernández, José Ricaldi, Luis Alejandro

The application of the Kuz-Ram model for the prediction of fragmentation is used worldwide, in Coimolache Mine it was used to determine blast domains and optimize the process by obtaining drilling patterns that meet a required X80 and reducing the uncertainty of drilling.

Feb 1, 2020

By María Rocha, Benjamín Cebrián, Roberto Laredo

"Ring blasting designs have to achieve different goals in order to become efficient whether is done in up hole or downhole fashion. Ore recovery/dilution control, fragmentation and drift integrity all have to be taken into account when selecting parameters such as burden, spacing, linear explosive density and stemming. Blast energy simulation allows identifying contours of rock breakage and fragmentation, thuschoosing a combination of spacing at the end of holes and appropriate burden. Also, simulations are keyto concentrate energy levels on the mid part of the ring while making sure there is not too high of energy concentration around the drift, which integrity is needed for a safe ore mucking."

Jan 1, 2017

By Hubert den Dikken

ache, especially when it comes to forwarding of small quantities. Air transport is limited to 1.4 explosives on cargo aircraft and 1.4S classified explosives on passenger aircraft, so most samples cannot be transported by air. Ocean transport is a possibility, but due to stowage and segregation regulations of the IMDG code, a very expensive one. Road transport is often the only solution, but high explosives require special trucks with licensed drivers. The solution to these logistic problems is solved by creating a 1.4S (Class C) classification for all high explosives, when packed in special containment vessels.

Jan 1, 1995

By Bill Romanchuk, Real Doucet

Suncor Inc. has been operating the first commercial tarsand open pit mine in the world since 1967. Drilling and blasting operations are required to facilitate overburden removal and tarsand mining by bucketwheel excavators.

Jan 1, 1985

By Michelle Crull, Susan Hamilton

Explosives safety requirements in the United States began in 1909 when the American Railroad Institute questioned explosives manufacturers regarding distances necessary to protect employees and property. In response to this inquiry, a group of explosives manufacturers collaborated to study over 200 explosive accidents. This study resulted in the 1914 American Table of Distance (ATD) published by the Institute of Makers of Explosives (IME). The 1914 ATD provided suggested separations between explosives and inhabited buildings, public highways, and public railways.

Jan 1, 2010

By Roger Lucas, Dale Nies

The McLaughlin Mine is an open-pit disseminated gold mining operation. Homestake Mining Company's approach to solving some of the blasting problems inherent to this type of deposit provide an interesting case history. Geology, although unique and site specific, is overall similar to other mines within the Western United States over-thrust belt and demonstrates an excellent example of the blasting conditions and requirements common to most of these operations.

Jan 1, 1990

By Alejandro Ferrada Vergara, María Jesús Barros Godoy

The need for a basic method for selecting explosives based on rock mass or intact rock properties for mining and construction arises from the limited consideration given to these factors when choosing among products and also an implicit overestimation of the explosive power to fragment the rock. This study highlights the importance of evaluating different properties such as rock strength, deformation, fracturing, detonation velocity and energy release when selecting explosives. The concept of characteristic impedance, which considers rock strength against shock waves generated by explosive detonation, is introduced. Understanding this concept is crucial for assessing explosive behavior according to various rock types. The study concludes with a practical guide table that categorizes rock properties and provides recommendations for selecting explosives based on rock mass and rock properties. However, it is important to consider other relevant factors, such as the presence of water or nearby instabilities, which can influence the final choice of explosives.

Jan 21, 2025

An explosive's velocity of detonation (VOD), can be used to indicate a number of important characteristics regarding the product's performance under specific field and test conditions. A number of new characteristic and transient VOD curves have been identified in the field, which can be used to evaluate explosive performance, control ground vibration amplitudes and frequencies, select the correct amount and type of stemming for use at the collar and in stem decks, eliminate explosive desensitization, evaluate primer performance, design air deck based blasts, evaluate contaminated explosives and to overcome post blast noxious fumes.

Jan 1, 1994

By Enrique Munaretti, Vitor Rosenhaim, Jair Carlos Koppe, Joao Francisco Feijo

The B3 mine is a multiple coal seam strip mining in operation in Rio Grande do Sul, the southernmost state in Brazil. A traditional truck & excavator operation is used to remove the overburden and selectively mine coal seams, ranging in thickness from 30 cm (1 ft) to 2.5 m (8.2 ft). Blasting is required in order to excavate part of the sedimentary rock overburden where the rock is too hard for mechanical excavation, and to mine the coal seams, selectively.

Jan 1, 2012

By L D. Santis, L Wardrip

This paper begins with a summary of the development of the sheathed explosive charge from it's conception by the Bureau of Mines in 1981 through the evaluation of its safety, culminating in revisions to the Code of Federal Regulations (CFR), Title 30, Parts 15 and 75 which provide for its approval as a permissible explosive and safe use in underground coal mines. In 1989, Austin Powder Company decided to market a sheathed charge and proceeded to develop a commercial version which they call the Rock*Buster. The Rock*Buster was tested by the Bureau of Mines and subsequently approved as a permissible sheathed explosive unit by the Mine Safety and Health Administration (MSHA). Marketing of the Rock*Buster began in the Spring of 1990. In May 1990, the Rock*Buster was first used in an underground coal mine, Jim Walter Resources' (JWR) No. 4 Mine in Brookwood, AL. Trials with Austin's units were impressive. Representatives from MSHA, the State of Alabama, JWR, the United Mine Workers, and other local mining companies observed the charge break large boulders on the surface. Later, the charges were used underground to break large rocks from a roof fall that were obstructing ventilation. During its first week on the job, the Rock*Buster reduced the downtime experienced on JWR's longwall sections by quickly taking care of problem roof falls which halt operations.

Jan 1, 1991

By C A. "Hawk" Hanger

"The paper that will be presented is an in-depth study of sequential blasting using standardnon-electric shock tube down hole timing along with surface M.S. connector timing.Included also will be a discussion on the advantages in fragmentation, digability, oredilution' and ground vibration versus the common practice of row by row blasting. Alongwith the written presentation, several visual illustrations will be included. The visuals willrefine the actual direction and predicted movement of the shot involved."

Jan 1, 1993

By Paul Worsey, Matthew K. Coy

New blasting mat designs are currently tested in the field on actual blasting jobs and only undergo qualitative rather than quantitative assessment. The majority of matted blasting occurs in trenching in which the blast designs and field conditions vary considerably. In order to assess a new blasting mat material and design, a new standard test was devised.

Jan 1, 2015

By Curtis G. Kremer, Jeffrey L. Brummert

Blue Circle Cement's Ravena, New York quarry mines approximately 6.7 million tons of limestone per year. Blasting occurs approximately twice a week on three separate benches. Shots average 60,000 tons but can range up to 140,000 tons. Ongoing scrutiny of the drilling and blasting program allows for maximum blast efficiency which results in lower overall mining and crushing costs. Close cooperation between management and explosives supplier assures Blue Circle Cement's objective, "To develop, implement, and continuously improve a measurable drilling and blasting system that will optimize the total mining and crushing costs while ensuring compliance to safety and maintaining or reducing the environmental impacts of blasting".

Jan 1, 1994

By Yeon-Ho Jin, Eui-Haeng Heo, Yun-Seok Park, Sung-Oong Choi, Hyung-Dong Min, Min-Su Jeong, Seung-Joong Lee

As rock fragmentation in bench blasting can affect the following process such as loading, hauling and crushing, its good control is essential for assessment of blasting efficiency and production cost.

Jan 1, 2015

By Robert Slivinski, Kyle Hobbs, Michael Stern, John Willox, Brad Jewson

Prairie Mines & Royalty Ltd. produces over 12 million tonnes annually of thermal coal for TransAlta’s Sundance and Keephills power stations from the Highvale Mine. This opencast mine is next to a lake and is surrounded by cottages and farms, which means that blast vibrations and air overpressure have to be kept to a minimum.

Jan 1, 2008

By Keith L. Bockelman

The Colowyo mine is a unique surface coal mining operation because it is a multiple seam pit. Using a combination of a shovel-truck and dragline operation, Colowyo mines 8 seams of coal to a depth of 400 ft. Over the past 3 years a number of operational changes have occurred, one of which is the implementation of blast casting. Through this implementation Colowyo has been able to eliminate over one million cubic yards a year, which would have had to be removed by the shovel-truck operation. This has also brought about a significant decrease in the stripping cost per ton within the dragline operation.

Jan 1, 1985

By Shadrack Nuamah, Erik Westman, Bright Afum, Jesse Addy

Rock fragmentation is the most critical aspect of hard rock production blasting due to its significant impact on drilling and blasting costs and the economics of subsequent loading, hauling, and crushing operations. This study analyzes current cost trends in the drill and blast operations of an anonymous open pit gold mine and proposes cost-effective drill and blast geometric parameters. The investigation focused on one operational pit with provided design parameters for two shots, shot 1 and shot 2. Existing blast parameters and two additional proposed sets of geometric parameters were evaluated using the Kuz-Ram and Chung and Katsabanis fragmentation models to estimate mean fragment sizes. The results indicated that the proposed blast parameters produced estimated mean fragment sizes within the mine’s desired range (not exceeding 45 cm). Additionally, the explosive energy was utilized efficiently per in-situ material blasted. The proposed parameters increased the estimated total volume of in-situ material fragmented by approximately 14% for both Shot 1 and Shot 2 compared to the current parameters. Furthermore, adopting the proposed blast parameters could lead to significant cost savings. The evaluated total drill and blast cost savings were approximately 11% for Shot 1 and 12% for Shot 2. These savings stem from the increased efficiency and effectiveness of the blast operations, highlighting the potential for substantial economic benefits. This study demonstrates that optimizing blast geometric parameters will allow open-pit mines to achieve desired fragmentation, utilize explosive energy more effectively, and realize considerable cost savings in drill and blast operations.

Jan 21, 2025