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By Charles W. Trettel

Confined explosives upon detonation produce a chemical reaction generating expanding gases that result in fragmentation of matrix a chemical to mechanical transition. A 100% energy conversion during transition is difficult, if not impossible, to achieve. There are numerous variables that affect energy transition. Although fragmentation is the most often used criteria to determine shot efficiency, the escaping energy profile provides additional data as to the efficiency of a blast. Escaping energy can also have deleterious effects in the form of ground motion.

Jan 1, 1975

By Pierre-Louis Migairou

After a period of development and experimentation ranging over 20 years, electronic detonators have now come to maturity and are becoming the first choice in many diverse applications like tunnelling, civil works, demolition works, quarrying, large scale open pit mining and underground mining. This paper demonstrates the versatility of electronic initiation systems by detailing a number of case studies in several applications as different as their geographical locations, and gives specific reasons explaining the popularity of electronics in each case.

Jan 1, 2009

By Qingshou Chen, Gongbo Li, Hengqian Ran

A method for safe fracture of rock, concrete and other brittle solid material using dynamic water pressure by explosion is provided. The propagation of the pressure is studied with Allievi water hammer theory. Wave equation and velocity formulas of the pressure propagation are shown. The dynamic water pressure is tested in the lab. The propagation of the pressure is simulated by MMIC-2D. The results of fracturing rock in the lab and on a quarry are presented.

Jan 1, 2000

By Calvin J. Konya

The Woodville Lime and Chemical Company Limestone Quarry is located in Sandusky County, Ohio. Fifty years ago, when quarrying began, it was situated approximately two miles from the town of Woodville. Today new houses border the quarry property within 1,500 feet of one of the working faces. During the past two years, the operation has systematically changed the blasting program to achieve better fragmentation, lower costs, and to maintain good relations with the local property owners. This paper will discuss systematic changes made in the blasting program to increase productivity and reduce costs.

Jan 1, 1977

By D. K. Ingram, G. L. Mowrey, T. R. Rehak

This paper summarizes flyrock and blast area security fatalities from 1989 to 1999 and examines the causative factors. Coal and nonmetal mining used about 43 billion pounds of explosives and blasting agents between1989 to 1999. A majority of this consumption was used at surface mines. Accident data indicates that flyrock and lack of blast area security were the primary causes of blasting related injuries in surface mining. Fatal injuries due to lack of blast area security were attributed to: failure to clear blast area; failure to follow instructions; inadequate guarding; inadequate blasting shelter; and unsafe location.

Jan 1, 2002

By Terry Graf, Bill Thompson, John Guenther

SYNCRUDE CANADA LTD.. operates the largest synthetic crude oil production facility in the world. Over 60,000,000 Bank Cubic Metres of oil sand is mined each year from their open pit located in Fort McMurray, Alberta. Despite the extremely cold temperatures encountered during the winter months and the problems associated with frost buildup, SYNCRUDE has continued to operate on a 12 month per year basis. In 1989 SYNCRUDE mine management embarked on a comprehensive Frost Blasting program to improve mine production of their oil sand moving equipment. The following paper will discuss the development of their frost blasting program to its current status.

Jan 1, 1993

By Omer Yilmaz Erkoc, Gulsec Uyar Aldas

Blasting techniques, which have been used for a long time in Turkey, are powerful and economical tool in producing raw material in mining, quarrying, construction .etc. industries. The development of the society within the world has resulted in a substantial increase in the scale of such industrial projects. However, the expansion of such activity has been matched by an increased public awareness of environmental issues, particularly when it occurs in relatively close proximity to residential areas. One of the most troublesome issues facing the mining, quarrying and construction industries when carrying out their blasting activities is that of ground vibration. Because, blasting induced ground vibration can reach to very far distances from the source and has the potential for damage to concern to the inhabitants of property.

Jan 1, 2002

By Richard Scales, Giles Hellyer, Ian Travers, Dean French, Peter Bellairs

"The Mt Whaleback iron ore mine is located in the Hamersley Province situated about 1OOOkm to thenorth of Perth, the capital city of Western Australia. A small but significant portion of the waste in Mt Whaleback presents problems due to its ability to react with normal commercial bulk explosives resulting in premature detonations, two of which occurred at the mine in 1983 causing great consternation as well as disruption to the mining operation. The techniques and procedures developed to overcome this problem were based on the use of tough durable, acid and heat resistant liners to provide a physical barrier separating the explosive from the rock togetherwith the development of an accurate down the hole remote temperature logging technology. The liner technology was developed due to the inability to produce a reliable inhibited ANFO despite exhaustive mine based testwork."

Jan 1, 1999

By G. R. Adhikari

A major part of mineral production comes from surface mining and there has been a rapid growth in this sector with the deployment of high capacity equipment. The importance of blast design combining appropriately both theoretical methods and practical approach has been well recognized in the field of surface mining. It is known that blast design has a direct consequence on productivity, safety and economic viability of these mines. Blasting is the most common method of breaking rocks in mining, but it has to be cost-effective. In coal production, for instance, drilling and blasting account for 25 percent of the total procution cost. In hard rock mining, the cost of drilling and blasting is about 40 percent. Due to ever increasing concern for cost-effectiveness together with environmental consciousness, designing blasts for each application has now become a stringent requirement and indeed a challenging task as well.

Jan 1, 2002

By Tassilo Baur

Explosives are used in the entertainment industry in a wide variety of applications. Live performances such as automobile races, air shows and the like have incorporated the use of explosives into their programs. Even art work has been created employing explosive materials and techniques. The primary entertainment use of explosives, however, remains in motion pictures, television, theater and related fields where it comes under the auspices of special effects. Much of it falls roughly into the category of demolition, though the object being demolished may range from a cigarette in a person's mouth or clothing worn by actors to large objects such as automobiles, aircraft, or boats. This paper will attempt to provide an overview of the materials and methods by which these special effects are created as well as highlight the unique problems encountered in this field and their often equally unique solutions.

Jan 1, 1992

By James Ludwiczak

This paper consists of the conduct of a forensic criminal investigation of the components, construction, use, and functioning of two suicide bombs. As the title states, the task was to form professional opinions as to whether the bombs would work, would cause property damage, and would injure or kill. The bombs were created and installed by a defendant in a Federal death penalty case where the defendant’s daughter was killed in a shootout with the West Virginia State Police. The two black powder bombs were placed under the front seats of the defendant’s automobile and were designed to function by the use of a toggle switch connected to the automobile’s cigarette lighter. The forensic work first consisted of an inspection of the remains of the wiring system and bombs at the Bureau of Alcohol, Tobacco, and Firearms Laboratory, in Ammendale, MD. This was necessary to determine and detail the wire diameter and lengths, the lengths and size of the wire used, the type of toggle switch used, the type of containers, the type of rocket motors used to initiate the black powder, the manufacturer and amount of black powder used in each bomb, and the type, wraps, and amount of duct tape used for the construction of each bomb. Using this data, tests were conducted by duplicating the wiring system and the two bombs to insure that the system functioned properly. Each bomb was duplicated and initiated to observe the violence produced when initiated in the open air. Duplicate bombs were placed under the seats of a similar type of automobile and initiated. The purposes of the tests were to duplicate the bombs, to observe the violence of the initiation, and to observe the damages to the automobile produced by the initiation.

Jan 1, 2007

By Fumihiko Sumiya, Yukio Kato, Yoshikazu Hirosaki

Secluential blasting is one of the most popular methods in blasting. tiowever, it is well known that an emulsion explosive can be dead-pressed by dynamic pressure generated by the previous detonation. It is difficult to gain the expected blasting performance due to tb.e malfunction of explosive caused by deadpressing and shock desensitization. Such malfunction of an explosive is undesirable for safety blasting operation. Voids in the emulsion explosives will considerably affect the performance of explosives such as sensitivity, detonation velocity (DV), pressure-resistance and so on. To clarify the detonability and the performance of precompressed emulsion explosives, the DV was measured. Three types of microballoon or micro bubble ; two types of glass microballoon(GMB), resin microballoon@MB) and chemical gas bubble ; were used as sensitizers for the sample emulsion expiosives. The underwater explosion test was carried out to load dynamic pressure into the sample explosives. The dynamic pressure was generated by the detonation of a donor explosive, and the DV of the sample explosives as acceptor was measured by ionized gap terminals. The dynamic pressure level and initiation interval for the donor and the acceptor were chosen as experimental factors. The detonability was carefully investigated at short initiation intervals taking into consideration the interaction between same delays caused by the deviation of the ignition time of the electric detonators. From these experiments, the following results were obtained ; A) The DV of precompressed emulsion explosives was low compared with that of uncompressed emulsion explosives in all pressure conditions. B) The decrease of DV in the sample explosives sensitized by GMB s was larger than that of DV in the sample explosives sensitized by RMBs or chemical gas bubbles. C) The recovery of the detonability occurred rapidly in the sample explosives sensitized by RMBs and chemical gas bubbles. However, a long period was needed for the recovery of detonability in the sample explosives sensitized by GME! s. It was concluded that the type of microballoon and micro bubble significantly influenced the detonability of precompressed emulsion explosives.

Jan 1, 2002

By Rhys Baker, Tim O’Brien, Joshua M. Hoffman

This paper discusses this division of power as it relates to the explosives industry. Each branch is responsive to the public and the processes through which each promulgates regulation and legislation require public input in different forms.

Feb 1, 2020

Hello, everyone. Way back in 1965, Devine and others at the US Bureau of Mines showed that a presplit fracture plane did not affect vibration levels transmitted across the plane (RI 6695).

Jan 1, 2010

By Joshua Hoffman, Catherine Johnson, Braden Lusk

The practice of dual initiation using precise timing from electronic detonators in boreholes is thought to be beneficial for increasing fragmentation at a desired location in the rock strata. This increased capacity for fragmentation is understood to be a product of both the collision of detonation waves in the explosive column and an increased energy liberation rate, each resulting from dual initiation. In addition, the collision of shock waves from two adjacent blast holes is suggested to improve fragmentation at the location the two shock waves meet, which can be controlled with precise timing. This paper presents the results from scaled laboratory experiments where converging detonation waves and shock waves were studied.

Jan 1, 2014

By Stephen Chung, John Carpenter, Scott Gosch, James Breedlove

While controlling fly rock and ground vibration in quarrying in the neighborhood of a residential area, producing good fragmentation and keeping different grades of material separated in a muckpile are important in maintaining the productivity of quality aggregates. This paper describes a single row production blast for the study of fragmentation and displacement in the grade control carried out at a quarry of Barrett Paving Materials Inc. in Sylvania, Ohio. Digital video imaging was used to monitor the blast-induced motion of the bench face as input to the DMC_Blast (Distinct Motion Code), for the analysis of the formation of the muckpile. The actual digitized blast video and the DMC_Blast simulation are compared. The displacement and mixing of all the inter-bedded limestone layers are made visible in the simulated cross-section of the muckpile. The apparent fragmentation analysed with PowerSieve is also discussed.

Jan 1, 2001

By Kai Nielsen

Drilling and blasting design results in a fragmentation that will have an important economic influence on all subsequent operations such as loading, transport secondary blasting and primary crushing.

Jan 1, 1987

By Richard N. Snyder

In this system for connecting blasting caps to the initiation source, the need for a redundant design structure provides more reliable method of explosive initiation. This is accomplished by using a complete system starting at the blasting control, through the initiation line structure through the initiation line and connecting blocks to the blasting cap. The connecting structure between the initiation device and the blasting caps may be connecting blocks or other means.

Jan 1, 1995

By Roger L. Keller

This paper examines the aspects of differing types of blasting cuts in underground headings with consideration to the reduction of number of holes and costs. At least one comparison study is related where costs per advance meter were significantly improved. The technical aspect of the paper covers a study of the effects of various blasthole delay intervals on resulting crater volume, ground vibration, and fragmentation for six hole V-cuts.

Jan 1, 1989

By Trevor Garbutt, Peter Bellairs, Jason Sander, Glenn Shaw

The Yarrie Iron Ore mine is located in the Pilbara region of Western Australia some 200km eastsoutheast of Port Hedland, the closest large regional centre. The mine is owned by BHPIO who has contracted a large Australian mining contractor Roche Bros to be responsible for the total mining, crushing and trainloading functions. This paper describes a drill and blast optimisation program, resulting from the introduction of a new emulsion matrix called Titan@ Red used to manufacture both HANFO and pumped emulsion ANFO blends.

Jan 1, 1999