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By Mark S. Stagg, Norman S. Smith, Rolfe E. Otterness, Stephen Rholl

Blast design parameters were studied in an attempt to quantify their relationship to rock fragmentation. The Bureau of Mines conducted a series of 29 reduced-scale shots at the University of Missouri-Rolla's experimental mine with bench size from 40 to 80 inches. Design parameters varied were burden, spacing, explosive diameter and stemming-explosive length. The shots had 3 or 4 blastholes fired at delays of 1-4 ms per foot of burden, based on previous tests that showed hole interaction could improve fragmentation by 12 to 20 percent over single-hole shots or simultaneous firing. All rock, 2000 to 23,000 pounds per shot, was screened and weighed to determine the fragmentation size-weight distribution.

Jan 1, 1991

By W C. Burkle

A rather common observation over the last several decades at least has been that rock or ore properties influence blasting results more than does the explosive type that has been used in the blast. It we accept that premise than it is held here that the material to be blasted should receive even closer attention as to its properties. Several years ago, Dr. Richard Ash published papers that pointed out the rock properties that mostly influence blasting. These principles are given attention in this paper. We have gone somewhat further - or lets say expanded this subject in regard to the role of rock structure in open pit blasting. Though open pit work is given some prominence, we believe that much can be observed and applied to underground mining.

Jan 1, 1979

By Claude Cunningham

AEL’s Electronic Delay Detonators are in routine use and growing in both volume and breadth of application in Africa. This trend will continue and grow internationally owing to increasing pressure on rockbreaking operations to conform to sustainable development principles. A fundamental breakthrough has been achieved, bringing production blasting into line with technologies, which leverage performance through tight monitoring and control. When moving from pyrotechnic systems, benefits are normally realized without having to adopt different timing patterns, but significant additional benefits are realisable by using the flexibility and precision of the electronic units to enter windows of timing previously closed. The higher price and increased care needed are a worthwhile investment, enabling operations to cross the chasm to stronger revenues, but the system must be robust and suited to the application and personnel. Economic models are vital for keeping track of the potential and achieved benefits of these systems. Some resistance can be expected from those who stand to lose income as a result of the improved efficiencies.

Jan 1, 2004

By Thomas L. Linton

The results of an extensive literature review and field experiments regarding the effects detonation of high energy explosive have upon various aquatic organisms are reported. These results were used to modify regulatory permitting criteria in Texas. Three separate field experiments were conducted. In the first study, surface placed charges were used in a marine habitat. In the other two, the charges were placed in drilled holes. In one, which was in a freshwater environment, the drilled holes were filled with drilling mud after placement of the charges. In the second, which was in an estuarine environment the holes were allowed to sit for thirty days prior to detonation to permit natural back-filling to occur by water transported sediments. A variety of aquatic organisms held in wire cages were exposed to detonations. Immediate and long-term effects of the exposure were determined based on external and internal visual observations. Damage to aquatic organisms was found to be reduced by placing the explosives in drilled holes and back-filling the holes prior to detonation of the explosives.

Jan 1, 1997

By Mark William Withey

Blasting safety in surface mining is a necessary industrial goal. Proper techniques and disciplines exercised during the blasting process enhance the probability of achieving that goal.

Jan 1, 1995

By Alan R. Gadberry

Good mine planning is critical to the success of a safe, cost effective mine. Many factors contribute to the overall success of an open pit mining operation: proper pit location and development, good drilling and blasting practice, and well conceived short range and long range mining plans.

Jan 1, 1981

By Stuart Pether, Cedric Goode

The Mt Morgans Minesite is located 800km North East of Perth, the Capital City of Western Australia. The surrounding region has been a significant producer of gold since the turn of the century. The mine was previously host to a township of approx 40 - 50,000 people.

Jan 1, 1996

By Joe Dannenberg

A word of preface: The material contained in this talk is not completely original. Many thoughts and actual words come from a fine little book called "1,000 Years of Explosives" by William S. Dutton. The book is now out of print, but if there is enough interest shown by this Society, perhaps we can have it reprinted.

Jan 1, 1980

By Donald J. Westmaas, Fred C. Drury

The Great Lakes Region, in the states of Illinois, Indiana, Michigan and Ohio, uses approximately 14% of the explosives annually consumed in the United States. While materials being blasted differ widely over this geographical area, a basis of comparing practices is proposed and evaluated.

Jan 1, 1979

By John R. Jr Tripi, Paul N. Worsey

Split round blasting is commonly practiced in underground uranium mining in the Big Indian ore belt located in Southeast Utah. The technique is used to prevent ore dilution by separately blasting the ore from the face.

Jan 1, 1985

By Antonio S. Aldana Selders

With special designed explosive and a system to lower down a heavy load of Explosives through 8" pipe results are achieved, the stimulation of sulphur production takes place. Well # 18-1063 at 515 meters below ground is loaded with 802 units of explosives with total weight of 1820 kilos to fill up the column of 93 meters of limestone & sulphur strata.

Jan 1, 1995

By R R. Vendebeek

The continuing evolution of explosives has most recently introduced emulsion explosives and heavy ANFO's to the market place. An explosives engineer has a multiplicity of explosives to choose from: dynamites, slurries, water gels, emulsions, ANFO's, and mixtures of some of these products.

Jan 1, 1987

By Jon Andrews

Purpose: To show how in managing risk in avalanche control blasting has changed throughout the years, and try to define the term “Acceptable Risk”. History: The history and the way we manage risk in avalanche control blasting to the avalanche control crews and public has change over the years dramatically. From the mid 1800s to about 1920 was the Risk vs. Rewards era, the Industrial Revolution. Now it is a Risk vs. Liability, the age of Liability.

Jan 1, 2009

By Yves Lizotte, Malcom Scoble, Pierre Michaud

The concept of optimum fragmentation in surface mining operations, i.e. the degree of fragmentation to which corresponds the lowest overall associated costs of drilling, blasting, loading, haulage and crushing, was developed more than thirty years ago. Recent field investigations using novel technologies, which have been completed by ICI Explosives Canada and by others, indicate that this ultimate goal of optimum fragmentation is closer to becoming reality.

Jan 1, 1997

By Norman S. Smith, Troy D. Harris, Richard L. Ash

In open-cut bench blasting drilling boreholes below grade level is normally considered essential to insure toes do not remain. The extra drilling and use of explosive below floor level are not only expensive but on occasion cause serious problems including severe floor damage and excessive ground vibrations. It has been reported that under certain circumstances explosive in the subdrilling has been successfully substituted by broken rock with its associated benefits.

Jan 1, 1978

By Edward Jr Walter

This paper discusses the problems that arise in the process of developing adequate explosives noise legislation. Case histories are used to illustrate how and where these problems arise and the course of action followed in overcoming them. It is imperative that those concerned keep informed as to possible legislation and be prepared to present solid facts that will insure fair and reasonable controls.

Jan 1, 1975

By T N. Hagan

Where explosion energy moves rock from the in-situ to its desired location without considerable assistance from digging and/or hauling equipment, good fragmentation is of minor importance. Maximum displacement must remain uppermost in the mind of the blast design engineer.

Jan 1, 1979

By John F. Vynne

This paper will discuss the application of available monitoring technology on blasthole drills with the goal being to reduce costs and increase productivity. Case studies from the monitoring of blasthole drills in North American open pit mines will be used to illustrate the ability to meet these objectives.

Jan 1, 1997

By D T. Froedge, Michael J. Nutting

A system consisting of an unlimited number of biaxial geophones that measure peak particle velocity and frequency has been developed and utilized at surface mines, quarries and construction sites. An ability to accurately measure ground vibrations completely surrounding a blast and to construct a vibration topograph has facilitated the study of blast design parameters and geologic factors on the resulting generation and propagation of the vibrations.

Jan 1, 1990

By Calvin J. Konya

When blasts are designed, we normally assume the best case situation. We assume that all burdens and spacings will be properly drilled, holes will be properly loaded, initiators will fire at the nominal time and the explosives will release their full energy. This type of precision can be obtained at a machine shop where precision equipment is available to do machining, however, in the field, no matter how well a blast is designed on paper, it most likely will not be done in the exact manner in the field.

Jan 1, 1990