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By Peter Bellairs

It is generally expected that drilling and blasting be a routine part of a mining process where the blastholes are drilled, left for a period of time and then primed, loaded with explosive, stemmed and then detonated via an appropriate surface initiation system. The occurrence of a premature detonation(s) therefore results in a great deal of consternation and disruption to the mining operation.

Jan 1, 1997

By James R. Kennedy

The recent drop in world gold prices is driving many northern Nevada underground gold mines to look for new ways to improve and enhance current mining operations. Continuous improvement programs at these mines are finding the means to increase mine productivity while reducing total production cost. This paper looks at developments in the drill and blast program at Independence Mining Company’s Murray mine.

Jan 1, 1999

By Sheila Luchansky, F M. Babcock, Daniel M. Sanders

A cooperative effort between a blasting vibration consultant, a blasting contractor, and personnel from the City of Las Vegas has dramatically reduced complaints from residential areas near developmental blasting projects. The principal methods used involved the preparation of an informative video recording which presents various aspects of the blasting operations, the design of a distinctive flyer which is attached to residential doors, and pre-blast meetings for information dissemination.

Jan 1, 1993

By Calvin J. Konya

Precision Blasting has designed easy to use, yet, highly powerful databases for storage and retrieval of blasting data. Three different Databases are available for blasting data management. The Vibration Data Management is a complete vibration record keeping system. The Blasting Data Management will record the information from the blasting report as well as the vibration data. The Explosives Inventory Control makes the control of explosives and initiators quick and easy.

Jan 1, 1991

By J P. Tidman

The problem of blasting fragmentation has received a good deal of attention in recent years. Progress by the scientific method requires a good set of experimental data as a benchmark to test models. Recent models have become so complex that it is not possible to use the results of field data because the complete set of parameters needed to describe the rock and/or explosive are not available.

Jan 1, 1991

By Sung Su, Jui-Lin Chang

A new technique of dimensional stones blasting for achieving directional rock cutting by conical shaped charges is proposed in this study. This technique has many advantages like precisely controlling numbers and propagation directions of cracks under blasting, having a complete rock excavation face, and maintaining surrounding rock and slope’s stability. So it can be applied to quarrying, underground excavation, tunneling, rock slope blasting, bench blasting and dimensional stone blasting.

Jan 1, 2006

By Robert G. Lundquist

This paper is a brief summary of work done on mining applications of high energy projectiles. Full scale field testing already completed has used cannons to drive a tunnel, drill large diameter holes, do secondary breakage in an open pit mine, and scale loose rock from inaccessible pit walls. Other applications are suggested in driving development openings, particularly raises. The method will be economically feasible only if cheap liquid propellants are developed.

Jan 1, 1977

By Willard Pierce

Very few people will consciously decide to do an unsafe act. With that said, how many of us unconsciously put ourselves in harms way, sometimes even on a daily basis? Complacency on the job may have very little to do with not caring or a poor attitude. It may be just as simple as failing to continue to recognize the hazards surrounding us throughout the day. At the very worst, it is both.

Jan 1, 2006

By Shulin Nie

The dead-pressing phenomenon in emulsion explosives is wellknown. Research work on this subject has been carried out at the Swedish Detonic Research Foundation for the last few years. Several experiments with emulsion explosives under dynamic pressure condition have been carried out both in iron pipes and in blast holes in rock. The main object was to study the critical amplitude and duration of the pressure causing the explosive to be dead-pressed.

Jan 1, 1993

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 Todd B. Harrington, Dennis M. Lydon, Walter B. Sudweeks

Heavy ANFO products made by mixing ANFO (or AN prills) with a relatively small amount of emulsion (typically 15-30 percent) have become very popular in recent years. They are less expensive than straight, sensitized emulsion and maintain the good shooting characteristics of ANFO but have higher bulk strengths. Their use, however, is generally limited to larger diameter, dry boreholes. Smaller diameter, wet-hole quarries have not been able to widely utilize this low cost bulk product.

Jan 1, 1989

By J Paul Tidman, Stephen H. Chung

One of the requirements in open pit gold mines is to minimise the mixing of ore and waste. Dilution can be reduced by choke blasting and control of the initiating sequencing. The authors have used the DMC computer model (developed at SANDIA) to examine the effects of timing and charge distribution on ore dilution. The model has been calibrated by measurements of vertical uplift derived from high speed videos made at the Dome Super Pit in Timmins.

Jan 1, 1997

Drilling through unconsolidated material I need to drill blastholes through a mix of consolidated and unconsolidated material. This material is hung up in an underground ore pass. The total length of the holes would be approximately 200 feet. We have attempted to drill through the material with conventional ITH drilling, but were unsuccessful. Does anyone have a suggestion? I am more than willing to bring in a contractor to do the job, if they have solid experience with this type of problem.

Jan 1, 2011

By Jerome S. Brower

Quadrex-L is a two component liquid explosive which was developed by J. S. Brower & Associates, Inc. to facilitate handling and shipping, and use in unique applications, while emphasizing safety. It may be advantageously used for all explosive applications. Quadrex-L can be introduced into a preinstalled container configuration and may be easily drained or flushed from these containers when necessary to do so. This characteristic can be effectively utilized to reduce the hazard period during assembly or disassembly operations.

Jan 1, 1975

By Charles Joyce, William C. Burkle, Dan Murphy

Rare indeed has a major cross country natural gas pipeline met and surmounted such obstacles as the Iroquois Gas Transmission Line from Canada to Long Island, New York. Of the 370 miles long length a fair estimate has been that 1/3 or 122 miles were across rock country. Spread One, Four and Five were particularly difficult. If is estimated that over 75% of the required blasting was on those three spreads. The term "spread" goes back to the old term of describing a ranch.

Jan 1, 1992

By James Keenan

Mesabi Range blasting has evolved in over a century of mining. The obstacles including: hard and heavily jointed rock, bitter winters and frequent wet holes; combine to create a unique challenge for blasters. This paper documents current pattern designs, powder selection and loading practices for these seven mines that consumes as much as 130 million lbs of explosives each year. Blasting is characterized by wide burdens and spacings, large diameter holes (up to 16-inch) and bulk loading of augered and pumped emulsion/prill products.

Jan 1, 1996

By David Flores, Benjamin Cebrian

This paper describes extensive engineering approaches to achieve both dilution control while not hurting fragmentation in the very hard, massive ore sections of a mine case study. Ore Tracker microchips are used to correlate performance of these designs at the SAG mill (bottleneck of this specific operation). Another gold mine uses the same technology to detect when and where operational dilution is happening. The system tells where flagging of the different ore bodies has been followed in order to detect which operators pass the excavation limits beyond ore control flagging.

Feb 1, 2020

By Michael Weaver, Dale L. Ramsey

The Pinkerton Tunnel open cut project is part of the National Gateway Clearance Initiative improvement project to achieve a minimum of 21 feet of vertical clearance along CSX Transportation rail corridor so that double-stacked intermodal railcars can be transported between mid-Atlantic states and their ports to midwest markets in the U.S. This project involved drilling and blasting of 1.2 million bank cubic yards of rock over a 14 month period while maintaining rail traffic of two passenger and 38 freight trains daily. See story and photos, page 6.

Jan 1, 2015

By Mark S. Stagg, Stephen A. Rholl

The U.S. Bureau of Mines has developed computer software which uses fast Fourier transform (FFT) techniques to evaluate blasting data. The software is useful because it allows blasters to evaluate 1) the frequency content of ground vibration time history data; 2) the effects of initiator scatter on the frequency spectra of ground vibrations; and 3) the fragmentation distribution of rock muckpiles from photographs. A one-dimensional version of the software was used in the first two cases. Monte Carlo techniques were used to simulate the scatter of initiators.

Jan 1, 1995

By Dale Preece, Stephen Chung, Richard Jensen

DMCBLAST_3D is a three-dimensional extension of the proven two-dimensional rock blast modeling code, DMCBLAST. DMCBLAST has been under development since 1987 and has successfully predicted the physics, mechanisms and results of a number of different types of rock blasting including, coal mine bench blasting, mineral mine choke blasting and underground stope blasting. Substantial effort has gone into the qualification and verification of DMCBLAST by comparing computer code predictions with real blasts in the field. Comparison with field data has also provided significant guidance to the development of the code.

Jan 1, 2001