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By Joseph S. Malesky

The discovery and development of explosives mark one of the most important findings in the history of civilization. Without explosives our vast economic enterprise concerning the mining of coal, copper, iron, aluminum, and various other ores could not function. Explosives are used in all kinds of construction works, in the razing of old buildings, blasting of trenches, driving of tunnels, and in many other instances common to our everyday life. For these reasons explosives are rightfully referred to as the forerunner of progress. An explosive may be defined as a substance (usually a mixture) that, when flame or shock is applied, yields readily to rapid combustion or oxidation, accompanied by the formation of such relatively large quantities of gases as to produce much violence and pressure which, in turn, react against their surroundings and cause what is termed an explosion. By their very nature the action of explosives is destructive and disruptive of adjacent materials. Decomposition of explosives can occur through deflagration, which is rapid burning or combustion, as in the case of black powder, or through detonation, which is an almost instantaneous disruption, as in the case of dynamites and blasting agents. HISTORY OF BLASTING WITH EXPLOSIVES At one time workmen obtained stone blocks for building by grooving the rock with crude picks, driving wooden wedges into niches in the rock, and pouring water on the wedges; the swelling of the wood forced out the blocks. As late as the 17th century, fires were placed against the face of rock to crack it, and water was sometimes dashed on the heated rock to shatter it by sudden cooling. The progress of our country is synonymous with advancement of the improved manufacture and extended use of explosives. Coal had been

Jan 1, 1981

By Joseph S. Malesky

The discovery and development of explosives mark one of the most important findings in the history of civilization. Without explosives our vast economic enterprise concerning the mining of coal, copper, iron, aluminum, and various other ores could not function. Explosives are used in all kinds of construction works, in the razing of old buildings, blasting of trenches, driving of tunnels, and in many other instances common to our everyday life. For these reasons explosives are rightfully referred to as the forerunner of progress. An explosive may be defined as a substance (usually a mixture) that, when flame or shock is applied, yields readily to rapid combustion or oxidation, accompanied by the formation of such relatively large quantities of gases as to produce much violence and pressure which, in turn, react against their surroundings and cause what is termed an explosion. By their very nature the action of explosives is destructive and disruptive of adjacent materials. Decomposition of explosives can occur through deflagration, which is rapid burning or combustion, as in the case of black powder, or through detonation, which is an almost instantaneous disruption, as in the case of dynamites and blasting agents.

Jan 1, 1981

By Joseph S. Malesky

The discovery and development of explosives mark one of the most important findings in the history of civilization. Without explosives our vast economic enterprise concerning the mining of coal, copper, iron, aluminum, and various other ores could not function. Explosives are used in all kinds of construction works, in the razing of old buildings, blasting of trenches, driving of tunnels, and in many other instances common to our everyday life. For these reasons explosives are rightfully referred to as the forerunner of progress. An explosive may be defined as a substance (usually a mixture) that, when flame or shock is applied, yields readily to rapid combustion or oxidation, accompanied by the formation of such relatively large quantities of gases as to produce much violence and pressure which, in turn, react against their surroundings and cause what is termed an explosion. By their very nature the action of explosives is destructive and disruptive of adjacent materials. Decomposition of explosives can occur through deflagration, which is rapid burning or combustion, as in the case of black powder, or through detonation, which is an almost instantaneous disruption, as in the case of dynamites and blasting agents. HISTORY OF BLASTING WITH EXPLOSIVES At one time workmen obtained stone blocks for building by grooving the rock with crude picks, driving wooden wedges into niches in the rock, and pouring water on the wedges; the swelling of the wood forced out the blocks. As late as the 17th century, fires were placed against the face of rock to crack it, and water was sometimes dashed on the heated rock to shatter it by sudden cooling. The progress of our country is synonymous with advancement of the improved manufacture and extended use of explosives. Coal had been

Jan 1, 1981

A BLAST can be "full of sound and fury," signifying nothing but a poorly confined charge, or it can be a muffled, well controlled explosion which moves the rock efficiently and places it in the desired location with the least amount of fuss and bother. Why one method will do the job and another proves to be almost useless is shown by the machine-gun camera studies of quarry blasting made by the Atlas Powder Co. staff. The sequence, or machine-gun, camera is the latest scientific device for the study of cause and effect factors in blasting. Movie cameras, previously used, although of some use, were limited because slow shutter speeds and small negatives failed to give clear, sharp prints. During World War II, the AAF developed the sequence camera, which figuratively stops the blast at regular intervals, making study and evaluation feasible. The camera is simple and inexpensive and offers material for accurate examination of blasting techniques. The machine-gun camera takes three 5x5 in. exposures per sec at a 1/450 sec shutter speed, four times faster than a movie camera. Negatives are 30 times larger than those of movie cameras, giving large, sharp prints. The rock movement is frozen on the picture as the sequence of the blast takes place. Pictures on this page show the advantage of individual machine gun photographs. But the sequences made possible by this camera give graphic, dramatic and conclusive support to recently developed detonation theories.

Jan 1, 1952

By Ron Glowe

This paper shows the potential of a new computer model, using the Glowe-Tech (GT) Tonnage Analyzer program to compare drilling and blasting results. This model uses the crushers and conveyors as measuring tools in aggregate quarries in the USA and Canada. All data is collected using commercially available kilowatt transducers and an analog input/output automation module. There are two areas of measurement used to compare results. The first area is the tonnage moved by key conveyors to show the split in products produced and the actual rate of production. If belt scale readings are not available then the Glowe-Tech Tonnage Analyzer can be used to convert kilowatts from the conveyor motor to tonnage. The second is the tons of rock crushed per kilowatt hour of energy consumption by the primary and secondary (optional) crushers. This modeling process works best if blasts are mucked and crushed in sequence. There are many other variables such as crusher types, crusher settings, screen sizing and actual geology in the pit that can influence the results, however if variables can be standardized then definite trends can be seen when comparing drilling and blasting results

Jan 1, 2005

By Hyde L. J

Blasting is one of the available technologies to be employed in underground excavation systems. In many instances it can be the only technology which is suitable. The recent moves towards more mechanised working systems is resulting in a reduced awareness of new blasting practices and technologies on the part of many excavation engineers. Recent developments in blasting systems can be utilised to significantly improve operating efficiency, reduce total cycle times, better comply with regional environmental constraints and reduce the total cost of underground excavation. Blasting is and will remain, a very adaptable and exciting alternative which is far from boring.

Jan 1, 1987

By Ronald D. Hill, Elmore C. Grim

The goal of blasting is to get maximum fragmentation of the consolidated material in the overburden with optimum drilling and blasting cost. The amount of fragmentation required is determined by the stripping unit to be used In overburden removal. Many coal seams must also be broken by blasting; this is conducted before coal removal. There are environmental factors as well as due regard for public safety, health, and welfare that must be considered in choosing the blasting plan. The blasting plan should be made during preplanning and is based on data from the overburden cores. Analysis of the data will help In determining the kind of drilling equipment and bit types that will be needed for overburden preparation.

Jan 1, 1974

By Thierry Bernard, Guy Gagnon

Blasting at very close proximity to urban areas is typically a situation where both local communities and mining stakeholders get nervous. The context becomes logically even more tensed when the blasting operations have to be performed above an old underground mine. When mitigating subsidence risks requires firing the largest possible shots, the nuisance control (flyrock, vibration, and noise) required by local and national regulations, contrarily urge for being more conservative.

Jan 1, 2014

By Thierry Bernard, Philippe Dozohne

May 13th, in the back country of Nice @arice) collapsed a complete piece of mountain, cutting the RN 2085 and destroying a part of Valabfre’s viaduct. The fist inspections of the site showed that materials had broken loose from surrounding cliffs, The geologists discovered that a block of several thousands of m3 remained suspended in cliff and that it presented a risk raised of gliding. Decision to destroy it by blasting in one blast was there taken by the French department’s council of the Maritime Alps. A race against the clock engaged. Indeed, the RN on 2085 is the main axis connecting the village of Saint Etienne de Tinee and the resort station of ISOLA in the centre of Nice

Jan 1, 2001

By Tianrui Xu, Chaohong Liu, Bangqing Ding

The authors were responsible for a series of large scale multiple chamber charge blasts conducted in the granite mountain area for making construction space on the southeast sea coast in China during 1993-1996. This paper describes the blast design and damage control of one mountain blast 320m in length and 280m in width in the vicinity of two wharfs and a dam. In order to obtain better rock fragmentation and muckpile, the explosive charge should be well-distributed in the mountain. The charge pattern, therefore, was designed with mainly 5 rows of tunnel charge in regular terrain in combination with a chamber charge in irregular topography area and the maximum burden was limited to be less than 38m. In order to protect the dam and wharfs the firing sequence was carefully arranged in 29 intervals and the distance between different charges of the same delay to the dam or wharf was taken into account as an additional delay interval based on the difference of p-wave propagating times. The maximum charge fired in an interval was also limited to less than 34t explosives through dividing the larger charge by a stemming deck.

Jan 1, 1998

A case history is presented where a variance was permitted by the court to change a 500 foot limit to 250 feet for blasting overburden at a surface coal mine in the proximity of a historic structure.

Jan 1, 1991

The Elgas Underground Storage Facility at Port Botany, Sydney, is the first purpose-built cavern of its kind in Australia and allows large capacity, safe and environmentally benign storage of Liquefied Petroleum Gas (LPG). The facility provides Elgas with the flexibility to source product at competitive prices and will ensure long-term security of supply. Construction has provided Orica Australia, formerly ICI Explosives, with a unique opportunity to provide a bulk explosive delivery system specifically designed to meet the exacting demands of the site (see Figure 1) and of the project.

Jan 1, 1999

By Jennifer Williams, Donald J. Berger

Originally built between 1913 and 1916, the Ashton Dam & Hydroelectric Facility has experienced various seepage and piping incidents since completion. Ashton Dam is located within 15 miles (24 km) of the historical Teton Dam failure site and about 2.3 miles (3.7 km) west of Ashton, Idaho. Numerous repairs conducted over the years ranged from filling sinkholes on the crest of the dam to placement of rockfill on the upstream slope to improve seismic stability. In addition, the existing low level outlet works was grouted full and abandoned in 1991 due to significant vibrations induced on the dam during its operation.

Jan 1, 2014

By Dieter Froelich, Giles Turcotte

In the near future, Bong Mining Company (BMC) will start mining a new deposit known as Zaweah II which is a narrow iron orebody requiring multiple row blasts with the bench floor as a free face. This called for the development of a new blasting technique. The article delineates the problem and its restrictions related to blasting. It also describes the approach which was taken for developing this new blasting technique which is essentially an application of the cratering theory with near spherical charges. Basic crater tests were conducted using various combinations of hole sizes, explosive strengths and delay patterns. From the results obtained, several alternatives were considered for production blasts and the most promising ones were evaluated.

Jan 1, 1980

By Paul Worsey, Dave McCool, Ryan Freeman, Chris Wolters, Rick Hines, John Bowles

Carroll Cave, located in Camden County, in south central Missouri, is one of the most significant caves in Missouri with over 12 miles of mapped passages and over 100 known but unmapped side passages. In the early 1990’s there was a breakdown of the originally excellent landowner/caver relations as the ownership of the only known entrance moved to a new generation and grottos squabbled for control. Subsequently the current owner of the natural cave entrance refused to grant anyone permission to enter.

Jan 1, 2003

By Gregg A. Scott, Gordon F. Revey

"The Folsom Dam is a 340-foot-high concrete gravity dam with embankment wing dams located on the American River about 20 miles northeast of Sacramento, California. Folsom Dam is operated andmaintained by the U. S. Bureau of Reclamation (Reclamation). As part of the Central Valley Project,Folsom Dam is a multipurpose facility providing water supply storage, flood control, power generation, and recreational opportunities."

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 G. T. Austin

Every year the United States consumes millions of dollars worth of abrasive materials as blasting media. Entrained in either a gas or liquid stream or propelled by paddles or wheels, they are directed onto the surface of another material to modify that surface. The modifications to impacted surfaces include cleaning, cutting, deburring, etching, finishing, and peening. Blasting media can be either organic or mineral abrasive materials. Information and data presented are for only a portion of the mineral abrasives, they are; fused aluminum oxide, coal slag, copper slag, garnet, metallic shot and grit, nickel slag, olivine, silica sand, silicon carbide, and staurolite.

Jan 1, 1994

By Martin Reed, John Wright

Blasters with the United States Antarctic Program (USAP) have developed techniques for opening access holes in floating sea-ice where the use of conventional drilling equipment is impractical. The blasting techniques have proven successful in sea-ice ranging from 8 to 15 feet thick. Previous published work has treated in detail blasting holes in floating ice from 2 to 6 feet thick.

Jan 1, 2001

By John W. Kopp, David E. Siskind

Over 4 billion pounds of commercial explosives are used by the U.S. mining industry every year with an excellent and improving safety record. However, accidents involving explosives are seldom minor. They produce a disproportionate amount of fatalities compared to other mining activities, as reflected in the relatively high severity rates. The U.S. Bureau of Mines (USBM) has been analyzing blasting accident data obtained from the Mine Safety and Health Administration (MSHA) to determine the most frequent causes of mine blasting accidents, examining trends in these accidents, and identifying areas of needed research. This paper is an update of three previous blasting accident studies conducted on 4-year intervals by the USBM and published in 1983, 1987, and 1991, and is based on a total of 869 blasting accidents.

Jan 1, 1995