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By Charles R. Welch, Charles E. Joachim

Underwater blasting causes not only ground shock but water-shock. Underwater shock attenuates less with range from the explosive source than ground shock and has the potential for killing fish or marine mammals or for damaging marine structures. The collapse and subsequent oscillation of the gas cavity surrounding the detonation can sometimes produce a greater impulse than the initial shock wave from the detonation. The airblast from underwater detonations can range from nuisance levels to damaging levels.

Jan 1, 1997

By Shannon Studden, Angela King, Allan Koski

Cliffs Natural Resources is an international mining and natural resources company with over 160 years of history. A member of the S&P 500 Index, the company is a major global iron ore producer and a significant producer of metallurgical coal. Throughout its history, employees have been the foundation of the company’s success, which has long embraced a focus on continuous business improvement.

Jan 1, 2014

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 G Alan Foster

Because of the marked human response to blast effects and inherent defects present in many modern structures the real possibility of being named as a defendant in a law suit faces most blasters. Until recently even frivolous law suits involved a great deal of expense since legal costs were inevitably incurred whilst waiting for your day in court, which typically occurred some 2-4 years after the alleged damage took place.

Jan 1, 1989

By R Keller, R Law

In the rush to beat the clock before the handover of Hong Kong back to China in June of 1997, an unprecedented amount of infrastructure work is being undertaken at a breakneck pace. In the middle of this construction explosion, on this island of barren granite , stands some of the most concerning and restrictive slope stability measures. So conservative, these measures impact blasting and vibration control to an extent unmatched anywhere in the world.

Jan 1, 1996

By Mark Odell, Bruce Northrup

In the hill country of Austin, Texas, Tom Kite has designed a golf course to be built in conjunction with a housing development entitled "Riverplace". The topography in this area is almost solid limestone, which made it necessary to use several types of surface blasting: Pre-splitting, ditch-line, sump shots, not to mention "fairway" cuts and even a sand trap or two.

Jan 1, 1985

By David A. Smith, B L. Jr Lindsey

Arkansas bauxite varies enormously in its consistency and composition which makes blasting a very difficult operation. Blasting rounds have to be designed based on each particular mine's ore characteristics. The variances are so great in some mines that blasting procedures have to be changed almost daily.

Jan 1, 1979

By James E. Jr Hargroves

With the ever-increasing population growth and modern trend to urban development, the expansion of utilities is a stable, mad or, and constant source of income for many. Blasting is a "necessary evil" to the utility contractor. It can make or break even the most solvent. Housing development expansion and higher treatment of effluents are causing utilities to appear in more congested areas. This paper discusses some of the aspects of utility blasting in the State of Virginia. Consideration is given to bid procedures, pre-blast surveys, record-keeping and practical application.

Jan 1, 1977

By Wang Xuguang Shen Yingfeng

Structure is the main aspect affecting the performance of emulsion explosive. Calculation of such structure parameters as osmosis pressure, interface area per unit volume etc. must be helpful to the understanding of the structure of emulsion explosive. This paper has solved the Laplace-Young Equation for simplified monodisperse emulsion system by Galerkin method, and gained the relationship between mean curvature, contact angle, volume fraction, fractional film area and interface area per unit volume. The paper also presents a new expression of osmosis pressure at non zero contact angle.

Jan 1, 1998

By George D. Raitt, Rudy Lyon

Until fairly recently, Down-The-Hole (DTH or DHD) hammer drilling was never really a factor in large scale open pit surface mining. It was a method confined to water well drillers, aggregate quarries and limestone mines where the hole size rarely exceeded 6-1/2" (165 mm). Also it was somewhat limited to the harder rock areas such as the North East and South East United States. The trend in the big mining pits for coal, copper, gold and iron, was for the big rotary drill rigs with lots of muscle in pulldown, bitload and rotary torque.

Jan 1, 1998

By John Watson

Overview: Intro and Product Use Trends ?? Packaged Explosives ?? Bulk Explosives ?? Initiation Systems – Conventional Initiation Systems – Electronic Detonators ??Q&A

Jan 1, 2006

By John A. Franklin, Norbert B. Maerz, D Linn Coursen

Accurate measurement of blast fragmentation is important in mining and quarrying operations, to monitor blasting and optimize blast design. A new digital photoanalytical method to measure the block size is presented here. Photographs of the broken rock are digitized, apparent size distributions measured, and corrections made for overlapping blocks, by means of an empirically derived correction function. The method was tested during recent full-scale blasting tests in Virginia, USA. It shows great potential as a practical aid to predicting, monitoring, and controlling the quality of the fragmented rock.

Jan 1, 1987

By R C. Berglund

Since the Republic Mine began production in the mid 1950's, drilling and blasting practices have continually changed. In recent years, progress has been achieved through the development of more precise blast engineering methods, in greatly increasing the use of non-water resistant ammonium nitrate explosives, and in changing to a non-electric in-hole delay initiation system. Also, recent experience indicates that ammonium nitrate fueled with nitropropane and methanol is a viable substitute for aluminized AN-FO.

Jan 1, 1980

By J Edmund Hay, T S. Bajpayee

The Bureau of Mines is developing a test to determine the initiating strength of commercial detonators. Various tests of "detonator strength" are in use, but many of them do not correlate well with each other, and so far, there is little evidence that any of them correlates well with the ability of detonators to initiate detonation in an explosive. Therefore, the Bureau decided to attempt a measurement of the ability of detonators to initiate detonation. To this end, an explosive mixture of adjustable sensitivity was developed. This mixture was nitromethane sensitized with ethylene diamine, the sensitivity being "fine-tuned" by the addition of nitropropane.

Jan 1, 1992

By R Fox, R Watt

On behalf of ICI's group of explosives companies around the world, a research programme is being undertaken to develop a new electrical shotfiring system which will have markedly improved safety features and operational advantages over existing initiating systems. The paper describes the development of the 'Magnadet' Electric Detonator and 'Magna' Primer and the field experience to date. It also indicates those areas where further work is being carried out on modification of the basic designs to meet specific application requirements.

Jan 1, 1981

By William R. Adamson, Carlos R. Scherpenisse

The successful development of surface mining operations depends, amongst other factors, on the successful creation of final pit walls which offer long term structural stability. The achievement of such walls will be much more feasible if the mechanisms of rock mass deterioration in the mine are well understood, permitting the control and reduction of this deterioration (or damage). The role of drilling and blasting in causing damage is widely accepted but rarely fully quantified. It is also true that the dependence of rock mass damage on vibration levels is only incompletely understood and little accurate field measurement is routinely conducted in the mining industry.

Jan 1, 1998

By Robert Hopler

Accidents associated with the storage of explosives prompted regulating the locations of such storage at least as early as 1719, when an act was passed in Great Britain. During the following years various refinements to the regulations were made, but a major explosion in 1864 in which there was destruction and loss of life as far away as 10 miles, led to the landmark Explosives Act of 1875. This act certainly had influence on regulators in the United States: when Massachusetts established an explosives distance/weight table in 1904 they referred to the prior British work. Later, Colonel Dunn of The American Railway Association convened a conference of explosives manufacturers to discuss safe storage. From this conference the American Table of Distances was established in December, 1910.

Jan 1, 2007

By G Alan Foster

Many complaints generated from blasting operations result from the marked human response to ground transmitted vibrations and air blast effects and so many authorities have considered the regulation of blasting in terms of human response rather than, as previously, in terms of preventing damage to structures.

Jan 1, 1981

By Mauro F. Dobran

The use of Slot Raises has been common for many years. The following presentation will compare various methods of developing these Slot Raises and introduce two new ones.

Jan 1, 1996

By Clarence Zink

The need for continual process improvement and innovation to reduce operating costs in the mining industry extends to the first significant encounter all production miners have with the rock: drilling blastholes. Material and design advances alone have greatly increased the productivity of today's tricone blasthole bit over bits used just a few years ago. Significant additional operating savings are being realized by utilizing improved air practices on blasthole drills, and by selecting drilling equipment designed to provide optimum air volume and pressure at the blasthole bit.

Jan 1, 1997