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By G Dean Barrett

Just one year ago at the 1986 Annual Meeting of the Society of Explosives Engineers, Dr. Calvin J. Konya presented a paper entitled "Presplitting Granite Using Pyrodex, A Propellant.'' Since that time more evidence has been developed to support the concept that "...gas energy can be the principal splitting force and that the stress wave or shock wave is not necessary to cause the presplitting action to occur." Work done in Vermont and Georgia is presented, and the ability to split granite without causing radial cracking of the bore holes is demonstrated.

Jan 1, 1987

The most common method for identifying the potential for blast damage is the peak particle velocity. But this can depend on many factors such as the type of blast, explosive, confinement, timing and the rock mass. The value must then be used to estimate damage. But the amount of damage will depend on the rock mass quality and the excavation size and shape. The amount of damage that can be accepted will depend on the purpose of the excavation. This paper presents a logical, but very approximate, procedure that the mining engineer can follow in order to assess the potential for damage in the control of that blasting.

Jan 1, 1987

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 Paul Worsey, Robert Sickler

Today, America's mining and construction industries are faced with operating under a condition of reduced profit margins. This makes the implementation of new technology far more sensitive to investment return than ever before. For this reason it is imperative that every effort be made to insure that new equipment and processes be designed to maximize their impact on improved quality, reduction in production cost and enhancement of safety. Using these principles as a foundation, a study was made to evaluate potential automation techniques for the blasting industry.

Jan 1, 1987

By Charles D. Sutton

Safety is an important part of the everyday activity for the explosives industry. The overall accident experience has not been adverse, however, many insurance companies have eliminated coverage for explosive related activities. The Nobel Insurance Group has responded to this insurance problem for our explosives customers. It is vital that safety efforts continue for all aspects of the business. The continuation of insurance policies for explosives, clearly depends on safety.

Jan 1, 1987

By Michael A. Peltier, Dennis V. D'Andreal, Larry R. Fletcher

Accident data obtained from the Mine Safety and Health Administration (MSHA) were analyzed by the Bureau of Mines to determine the most frequent causes of blasting accidents in U.S. mining and to examine trends in blasting accidents. This accident analysis is an update of a similar blasting accident study conducted by the Bureau and published in 1983. The analysis shows that there has been a recent reduction in mine blasting accidents: The annual average number of nonfatal injuries has decreased from 107 for 1978-81 to 46 for 1982-85. The annual average number of fatal injuries was reduced from 11.3 to 5.0 during that time.

Jan 1, 1987

By J P. Tidman, I J. Kirby, G H. Harries

The SABREX computer model is based on the fact that both shock waves and gas pressure are important in describing a blast. The treatment of explosive-rock interactions includes the influence of non-ideal detonation to make use of recent advances in that field. Details of the blast layout are defined from a comprehensive list of conditions the blaster can control (drill pattern, charging and hook-up). The program gives practical and graphic information about fragmentation, muckpile, damage and costs.

Jan 1, 1987

By G G. Paine, C V. B Cunningham, G Harries

The companies of the ICI Explosives Group have successfully used a wide variety of internal computer codes including BOBCAT, KUZ-RAM, ICRAX, XPLODE, BLEND, 3CRACK, MICBLAST, DETON, etc. In recent years the extensive experiences across ICI have been combined into a single compatible model engineered to worldwide technical service and customer needs for the prediction and assessment of blast results.

Jan 1, 1987

By P A. Lang

Canada is constructing an Underground Research Laboratory as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in stable rock formations. Careful blasting methods have been designed and quality control procedures have been used for the excavation of the access headings in the underground facilities. This paper describes the work done between 1984 December and 1986 December at the second level, 240 metres below surface.

Jan 1, 1987

By Roger L. Keller, John Dean Smith

The Amax Coal Company's Ayrshire Mine in Southern Indiana is faced with one of the toughest blasting applications concerning vibration in the nation. As a means of maintaining regulatory compliance the operation elected to exercise the option of frequency analysis. A site-specific computer processing program which suggests ideal delay interval ranges for the lowest vibration was utilized.

Jan 1, 1987

By Raymond H. Green, Mitchell W. Green

The authors examined the application of precise millisecond delay electric blasting at a well-known Vermont quarry. The paper explains how the use of a new high-accuracy electric delay detonator has improved fragmentation, raised productivity 10%, simplified blast design, and increased the ability to predict results from blasting.

Jan 1, 1986

By William D. Hissem

The purpose of this paper is to advise people about the methods, use, and possible applications of current "personal computer" hardware and software with regard to the economic cost analysis of percussion drilling equipment. The material content and orientation of this paper is toward those people who have just begun "PC" (personal computer) operations, and (or) those who are considering their use.

Jan 1, 1986

By A B. Jr Nunn, W C. Gould

Good community relations is a major concern at this central Virginia aggregate quarry. In this paper, the authors describe the use of a new electric millisecond delay initiation system that has reduced the average level of vibration by 27% since its use began in late 1984.

Jan 1, 1986

By S Lukovic, Vishwa Bhushan, Calvin J. Konya

Effect of each of these variables has been well characterized for ANFO. This paper presents results of underwater energy measurements for one watergel and one emulsion type of slurry explosive which were initiated by 3 types of initiators (one electric and two cords of different strength) in 2 and 3 inch diameter steel pipes. Results of this 2 x 3 x 2 factorial experiment show the effects of detonating cord on energy released by the watergel and the emulsion explosive. Effect of diameter and its interaction with cord strength have also been characterized for the two explosives.

Jan 1, 1986

By Eduardo Gonzalez Fernandez, Jaime Rios Vazquez

This report substantiates the connection that always exists between explosives and vibrations and draws attention to low frequency vibrations, which are the moat dangerous for the structures affected.

Jan 1, 1986

By Rahim G. Haghighi, Calvin J. Konya

Fragmentation is the fundamental concern of rock blasting and it measures the effectiveness of blasting. Fragmentation is sensitive to not only the interrelationship among the design variables, but also is sensitive to local geology. Local geologic conditions have a significant impact on the success of a blasting operation.

Jan 1, 1986

By Ed Jr Smith, Calvin J. Konya

The purpose of this paper is to describe the case history of a blasting project conducted jointly by Precision Blasting Services and Cherokee Explosives. It is the intent of the authors to show how blasting could be done in controlled fashion near very expensive computer controlled machinery. The job was done in minimal time with no complaints or allegations of damage in spite of the fact that blasting was conducted within five feet of the equipment and with the 32 acre plant fully operational, with machine operators working within 10 feet of the blasting site.

Jan 1, 1986

By Phil N. Bradbury

"During a routine belt tightening of all cost centers, the management at the Martin County Coal Surface Mines, located in Martin County Kentucky felt that a thorough investigation of the drilling and blasting program could possibly pinpoint areas where the cost could be cut without sacrificing production. Upon close inspection of the drill benches it was noted that the actual layout of burden,spacing and stemming varied a bit from the actual blast design that the management had outlined for the blasters. This paper will outline the method of reducing the drilling and blasting cost at the Martin County Coal Operation."

Jan 1, 1986

By Paul D. Dupree

This paper discusses the drilling and blasting techniques used in blast casting at a large western coal stripping operation.

Jan 1, 1986

By Tom Short, Paul Kunze

In this paper, the authors describe major changes in drilling and blasting methods instituted at the Zortman And Landusky Mining Company Properties to maintain the viability of these north central Montana surface mines in the present period of depressed precious metal prices. The authors explain how improved drilling procedures minimized problems due to uneven benches and floors. They also describe changes in explosives loading and delay blasting techniques which improved fragmentation, thus increasing metal recovery from heap leaching. Quantities were increased substantially and a new bulk explosives loading system was placed in service with a special down-the-hole bulk loading truck and storage facilities for bulk ANFO and bulk emulsion. At the same time, drill patterns were expanded by nearly 40%. The authors also describe a new technique of using explosives to selectively cast waste and ore in different directions so as to reduce the cost of separating the ore.

Jan 1, 1986