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By Paul Worsey, Gillian Worsey

The basic blasting class at Missouri S&T blast in the quarry at the experimental mine in preparation for the International Intercollegiate Mining (Mucking) Competition in April 2014.

Jan 1, 2015

By Y. Hirosaki, H. Hamashima, Y. Itoh Kato, S. Tanaka

The emulsion explosives show non- ideal detonation behavior, and its detonation velocity can be controled by selecting the size and adjusting the quantity of voids involved. To establish the technology to control the detonation characteristics of the emulsion explosives, some experiments have been carried out using resin balloons of five different sizes ranged from O.OSmm to 2.42mm in the average diameter. Detonation velocities of the emulsion explosives containing resin balloons of different size and quantity were determined for the charge diameter of 20-50mm. The detonation velocity at infinite charge diameter was compared with calculated ideal detonation velocity. The emulsion explosives containing large (0.5mm or larger) balloons showed big discrepancy between the measured and calculated detonation velocities, and the fraction of ammonium nitrate reacted in the reaction zone was estimated to be significantly low. It was shown that the reaction zone length was proportional to the size of voids involved. The critical charge diameter was determined for the emulsion explosives containing different resin balloons at the various explosive densities. It is large for the emulsion explosives containing large voids, and it was shown that the critical diameter is proportional to the distance between the void surfaces, not to the void spacing, the distance between the centers of the voids. The reaction rate of the bulk emulsion matrix seems to be the major factor that affects the critical diameter than the specific surface of voids. Good relationship between the critical diameter and the reaction zone length was observed.

Jan 1, 2000

By Jiang Han, J. F. Shao

Based on the rock blasting engineering, The Self-Organizing Map (SOM) network has been implemented for the concept and method of rock blastability classification. The Self-Organizing Map (SOM) is a neural network algorithm which is especially suitable for the analysis and visualization of high-dimensional data. It maps nonlinear statistical relationships between high-dimensional input data into simple geometric relationships, usually on a two-dimensional grid. The mapping roughly preserves the most important topological and metric relationships of the original data elements and, thus, inherently clusters the data. SOM allows easy data fusion enabling visualization and analysis of large databases of rock blasting engineering. As a case study, the classification technique based on SOM has been used to classify the rock mass blastability rank. It can be founded from this paper that the SOM networks can be developed well based on a comprehensive data set of rock blasting engineering.

Jan 1, 2002

By Robert A. Farnfield

This paper outlines the theory behind transfer functions and illustrates their application in the prediction of structural response to blast induced ground vibration. The ability to predict the response of a structure to a recorded ground vibration is desirable for a number of reasons.

Jan 1, 1994

By Claude Cunningham

Simple bulk energy rating of explosives obscures the realities of how these deliver their energy, and diverts attention from the key question of controlling blasting results. Explosive performance is directly related to the pressure pulse impacting on the blasthole wall. This is helpfully visualised by comparing the adiabatic expansion plots for explosives of interest on the right scales and axes. The simple comparison of a pure emulsion with pure ANFO illustrates the practical significance of the intrinsic behaviour of these opposed formulations, showing that the emulsion can be expected to work more by softening rock, while ANFO will tend more to crack it. The explanation for these differences lies in the high shock, low sustained pressure of the former relative to the latter. The technique is readily applied, if a good detonation code is available and able to swap data into a spreadsheet. Any differences between codes will emerge most strongly in comparing the gamma plots.

Jan 1, 2002

By Paul E. Thompson

Current magazine regulations are designed to avoid injury or property damage caused by accidental detonation as well as to store explosives securely. The primary emphasis appears to be the avoidance of unintended detonation or in the event such detonation occurs, the avoidance of damage to surrounding property. Adherence to these regulations largely serves the purpose intended but has caused difficulty in magazine sitting in built up areas. To the extent that magazine siting is too heavily restricted, other more significant dangers such as storage of explosives in more dangerous and less secure places may be encouraged. In summary, the regulations have served rural magazine locations well but may need further study for urban settings.

Jan 1, 1990

By P D. Katsabanis

Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction includes sympathetic detonation and desensitization of explosive charges as well as the modification of firing times of conventional pyrotechnic detonators.

Jan 1, 1995

By Jean A. McIntyre

The Office of Surface Mining (OSM) has twice proposed rules for a blaster training and certification program to implement Sections 515(b)(15)(D) and 719 of the Surface Mining Control and Reclamation Act of 1977.

Jan 1, 1980

By M Siefert, P Moser, T Oberndorfer

"The EC-project ""Blasting Control"" with partners from France, Austria, Italy and Greece dealt with the development of a diagnosis system, which enables blasting experts to investigate in detail on probable reasons of poor blasting results in underground drifting. The system incorporates monitoring of geometric, explosive, vibration and granulometry data. All data are compiled in a database and are provided for direct retrievement by demand of the experts in a graphical environment. This paper focuses on the advantages of such graphical system for both research tasks and applications in real testing situations. It describes the procedure of monitoring and presents a selection of graphical outputs generated during data processing immediately after blasting. Benefits of detailed monitoring in respect of detecting sources of errors are explicated by a actual example of a test series in a mine. The paper will conclude with an outlook onto the scientificresearch work which is planned to be based on the results of hitherto investigations."

Jan 1, 1996

By Wiliam Reisz

As we approach the peak season for thunderstorm activity it’s important to keep in mind that lightning still poses a serious threat to drilling and blasting operations. Lightning remains the number one cause of accidental detonation of explosives.

Jan 1, 2008

By N K. Jain, Rajesh Jain

This article has been written indicating the present trend in Blasting all over the World, so as to help in planning production and development of Industrial Explosives for the development of industries in all the countries in general

Jan 1, 1992

By Dale S. Preece, Stephen H. Chung

"A discrete element computer program named DMC_BLAST (Distinct Motion Code) has been underdevelopment since 1987 for modeling rock blasting (Preece & Taylor, 1989). This program employsexplicit time integration and uses spherical or cylindrical elements that are represented as circles in two dimensions (2-D). DMC_BLAST calculations compare favorably with data from actual bench blasts (Preece et al, 1993b)."

Jan 1, 1999

By Brad Johnson

Homestake Mining Corporations' open cut operation at Lead SD. experienced a highwall failure in October of 1993. The failure released a 75' section of rock wall at the 5280' level. It came to rest on the 5200' safety bench. Since work was in progress below the failure, this rock had to be removed for safety.

Jan 1, 1995

By Jay P. Tobin

This paper will address the legal standards applicable to construction blasting lawsuits and offer best practices suggestions for pre-blast inspections, documenting the construction blasting work, recordkeeping, and effectively participating and partnering in the defense of a construction blasting lawsuit.

Jan 1, 2015

By William C. Lane

The Pacific Northwest has an abundance of seamy, coarse granite and basalt rock. It is used primarily for road construction. Small quarries are opened nearest the road work to cut the cost of hauling. The crushers are portable. Small diameter holes 2 1/2" to 3 1/2" are placed close together to insure proper fragmentation. It is not unusual to load and shoot 100 to 700 holes 40' deep.

Jan 1, 1986

By D. Bartley, R. McClure, W. Reisz

Ever since the 8ms criterion was developed in the early 60’s there has been an ongoing debate among many blasters as to its actual value in controlling ground vibration. The perpetuation of the myth surrounding the 8ms window can be partly attributed to its simplicity and convenience as a means for regulatory compliance. Unfortunately, the mindset that many blasters have adopted has hindered the development and use of more effective techniques and in many cases can actually be counter productive to vibration control.

Jan 1, 2006

By Michael S. Wieland

The stress waves generated during delay blasting in underground or surface mines not only fracture the surrounding coal, rock, or other strata, but also impact delayed charges remaining in neighboring boreholes. This crossing wave interaction is a ubiquitous fundamental damage mechanism, ultimately responsible for numerous occurrences of misfires and flyrock. The hazards and waste from wave-induced malfunctions are Just the recognized tip of the iceberg. Undetected marginal performance of damaged delay detonators and desensitized charges poses a tremendous unresolved problem, resulting in the reduction of mining profits and the certain retention of unwanted risks.

Jan 1, 1988

By TA Louw, Dr CM Lownds

In an era where profits are constantly being eroded, mines are looking towards technology developments to assist them in solving mining problems and reducing mining costs. An emerging technology that could assist mines in becoming more cost effective is electronic detonators. Electronic detonators have been under development for several years. Over the past three years, the spotlight has fallen on commercial use of electronic detonators and the extent to which the promise of precise and programmable timing can assist mines with their environmental and productivity problems. This paper uses case studies to demonstrate both surface and underground applications where electronic detonators and blasting systems were used to solve typical mining problems such as vibration and fragmentation. Safety aspects such as hanging wall conditions and high wall stability also benefited from the use of electronic detonators. The paper also demonstrates how the use of accurate electronic detonators and blasting systems has resulted in improved/more even fragmentation with further downstream efficiencies. These efficiencies may include increased cast percentages, reduced oversized rocks, quicker cleaning times and increased production rates.

Jan 1, 2004

By Ryan Redyke, Jared Redyke

The demolition of an old power plant boiler house in Parsons, Kansas calls for the use of some linear shaped charges. The steel is thick and the structure is heavy but gravity can be a blaster’s best friend. This entry did not win in a very competitive category. We thought it was worthy of coverage in the Journal of Explosives Engineering.

Jan 1, 2015

By Michael S. Wieland, Thomas C. Ruhe

Delay blasting in underground coal results in shock waves traveling through the coal that can damage delay charges remaining in the blast pattern. Undetonated explosives which are dynamically desensitized or react sympathetically from shock wave impact ruin blast results. Such malfunctions, sometimes manifest as misfires, more frequently are covert weak detonations, and result in poor coal breakage and fumes with above normal toxicity. To reduce these mining hazards and resolve charge performance problems, the Bureau of Mines has developed and tested forty prototype rugged explosives in the laboratory. Rugged explosives work properly under difficult circumstances because they not only retain their shock initiation sensitivity but also are resistant to shock damage. This research investigation resulted in one candidate emulsion explosive, formulation #37, which passed all the permissibility tests required by MSHA approval regulations. However, approval was not granted because it reached shelf-life (would not shoot properly) seven months into testing. For research purposes, the remaining tests were conducted with a second batch of formulation #37. This paper discusses the prototype rugged explosive composition and permissibility test results. Where possible, for reference purposes, comparisons are made to a commercial product that has been approved. Further research work is required to overcome the noted deficiency of short shelf-life.

Jan 1, 1992