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By Jeff Wachendorf

As the title implies, this paper details the start of a cast blasting and the design flexibility required to satisfy different parameters encountered on a large coal mine employing cast blasting as the program has grown and evolved around the town of Colstrip, Montana. As strip ratios have increased, the need to adapt and find solutions to provide coal at a reasonable cost to the mine mouth power plants has risen. Colstrip, Montana has a long history of coal mining which dates back to the early 1920s when Foley Brothers began supplying coal strictly for powering locomotive engines.

Jan 1, 2015

By Dale S. Preece

A Discrete element computer program named DMC (Distinct Motion Code) has been developed for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements which are represented as circles in 2-D. DMC calculations have been compared with measurements on bench blasts in the field with relatively good comparison. Structural geology and joint sets have a significant impact on any blast and DMC has not, until now, included these effects. This paper discusses a recently added DMC capability for treating joints and bedding planes in bench blast simulations.

Jan 1, 1995

By Thomas A. Simpson, Yung-Kwaun Jow, Dennis L. Gamble

Construction of the $200 million Riverchase Galleria Mall in Hoover, Alabama was started in early 1984. The construction area consists of about 70 acres. The extensive building complex requires heavy concrete foundations which have to be poured during the early stages of construction and on a nearly daily situation so that contractual agreements can be met on a timely basis.

Jan 1, 1985

By Hu Wenjun

This paper changes the section of copper of copper to aluminum adapter bar into aluminum plate covered one face or double face with copper coat, and changes the conductor material of knife switch, fuse box, plug and socket into steel plate covered one face or double face with copper plate, and manufactures the composite (two layers or three layers) metal plates by means of explosion welding with the plates installed horizontally. Introduced in this paper are the blasting designing technique, manufacturing process and the electrical performances of the explosion bonded products. Besides, this paper presents the designing and manufacturing technique of cumulative charges and their time detonating units for cutting off the retired nuclear submarine pipes. Experiments on cutting off the stainless steel pipes by cumulative flow and on the time detonation are made. Keywords: explosive welding, electric, explosion bonded products, retired nuclear installation; pipe; blasting cutting; cumulative charge; time detonation

Jan 1, 2000

By James Stuart

Explosive components are common in electric power distribution systems. Basically, we use explosives either to open or to close a circuit very quickly, in order to avoid electrical catastrophe. We use explosives in these important applications, because explosive materials are compact, inexpensive, long-lived, powerful, and can be triggered instantly. A lead-alloy fuse will melt when excessive electric current passes through it. A small fuse of this type melts quickly. However, a lead-alloy fuse for high current levels must be larger, and takes longer to melt. Thus, at high current levels, a lead-alloy fuse offers inadequate protection, because electrical catastrophe might happen, before the fuse melts. We need faster-acting, explosive components.

Jan 1, 2009

By Joseph L. Uraco, Harry C. Verakis

The use of explosives in underground coal mines presents a potential risk for serious injuries and death to miners. Widespread disasters have occurred from the explosion of methane and/or coal dust initiated by blasting with explosives. Many of these disasters took place in the early 1900's when the use of black powder for blasting was prevalent. Historically, the investigations in the U.S.A. to develop and test safer explosives for blasting coal began in 1908 when a testing station was established in Pittsburgh, Pennsylvania. Since that time, great strides have been taken in the development of safer explosives. The use of safer explosives has significantly reduced blasting accidents in coal mines. Enactment of legislation, such as the Federal Coal Mine Health and Safety Act of 1969 and enforcement of regulations has also improved blasting safety. More recently, MSHA began a major revision of its regulations for blasting in coal mines. In 1988, MSHA published final rules for the approval and use of permissible explosives in coal mines. The approval requirements for explosives address testing and evaluation. The requirements include tests for sheathed explosives which represent a new technology. The use regulations provide increased safety protection for miners by including standards to address identified hazards. Major aspects of these standards, such as qualifications for blasters, multiple-shot blasting and the use of sheathed explosives are discussed.

Jan 1, 1992

By P. Katsabanis

Researchers in the field of blasting have been trying to develop ways of predicting fragmentation in the last few decades. The Kuznetsov equation estimates the average fragment size, XJ~, based on explosive energy and powder factors. Cunningham calculates the uniformity of a fragment size distribution using drilling accuracy, blast geometry and a rock factor A associated with a “blastability index”, which can be estimated from the jointing, density and hardness of the blasted rock mass. Knowing the mean size and the uniformity index, a Rosin-Rammler distribution equation can then be derived for calculating the fragment size distribution in a blasted muckpile. Analysis of existing data has revealed serious discrepancies between actual and calculated uniformity indices. The current integrated approach combines the Kuznetsov or similar equation and a comminution concept like the Bond Index equation to enable the estimation of both the 50% and SOoh passing sizes (X& and X& ). By substituting these two passing sizes into the Rosin-Rammler equation, the characteristic size (Xc ) and the uniformity index (n) can be obtained to allow the calculation of various fragment sizes in a given blast. The effectiveness of this new fragmentation prediction approach has been tested using sieved data from small-scale bench blasts, available in the literature. This paper will cover all tested results and a discussion on the discrepancy between measurement and prediction due to possible energy loss during blasting.

Jan 1, 2001

By Stephen John Brace

Increasingly, electronic blast initiation systems are being made available to the mining and construction community, both in South Africa and internationally. Indeed, in some parts of the world, perhaps half a dozen electronic products are being used, with a choice also of shock tube, electric and fuse and igniter cord systems. As these developments have taken place, improvements have been made in safety, reliability and accuracy, so much so that high performances in all these areas are now expected. However, disadvantages often seen by customers, other than : higher price, are decreased user-friendliness and loss of flexibility.

Jan 1, 1998

By Robert Hopler

RBH Note: At the time of this price list the handwriting was already on the wall regarding the ultimate breakup of the company under the Sherman Anti-Trust Act. The brand names Atlas and Hercules, noted on page 3 of this pricelist, would become the names of the new companies created from du Pont.

Jan 1, 2012

By Alan R. Cameron, William Forsyth, Tom H. Kleinel

Because good and bad blasting must be defined in terms of overall mining costs, blast optimization requires combined blasting and costing models. Furthermore, the models must be both accurate and comprehensive. A combined fragmentation and preliminary costing model was developed to investigate alternative blasting strategies.

Jan 1, 1995

By Jin Jingzhi, Wang Xuguang, Guan Li, Li Jianjin

Emulsion explosives are gaining a wider and wider commercial market and are displacing other composite slurry technologies. However, the grease-like state and essential thermodynamic instability of emulsion explosives cause inconvenience in production, transportation, storage and use and lead to gradual changes in performance. Emulsion powder explosives are designed to avoid these disadvantages. The formulation, process and properties of emulsion powder explosives made through a spin flash technology are described in this paper.

Jan 1, 1997

By Lewis L. Oriard

Both theory and experience tell us that spatially distributed energy sources generate a more complex family of seismic waves than do point sources. The resulting effects in the near field (for close-in blasting) are significantly different than those from point sources although, at great distances from the source, the seismic waves take on many of the characteristics of point sources and can often be treated as such.

Jan 1, 1992

By John J. Barnes

The advent of more powerful explosives, increased bench heights, and larger diameter blastholes has necessitated the use of presplitting techniques in sub-bituminous coal mines. The combination of these factors has increased the energy concentration during blasting, producing severe overbreak problems in the final pit walls. Presplitting with large diameter blastholes has proven to be the most viable method of reducing back break in sub-bituminous coal mines.

Jan 1, 1988

By Kai Nielsen

A model has been developed for sensitivity analysis of open pit bench blasting. The model simulates the cost effectiveness of various blasting designs in relation to the equipment used for drilling, loading, hauling and primary crushing. The simulations will give an indication of the optimum powder factor giving the lowest over-all costs for drilling, blasting, handling and crushing.

Jan 1, 1985

By Winfried Rosenstock

Following successful trials at Chuquicamata / Chile from February to May 2000 and from February 2001 onwards at Burton Coal Mine, RAG International/Thiess Pty Ltd., Queensland / Australia a significant advancement in blasting technology was achieved using electronic detonators. The mine now uses electronic intiation for the majority of overburden blasting.

Jan 1, 2002

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 Walt Meglasson

"Developing technologies in demolition equipment and processes have produced a newsophistication within the demolition industry. Yet, with increasing frequency, owners,architects, engineers, and contractors reject out of hand one of the safest and most effectivetools in the demolition industry today, specifically the use of explosives and blastingtechniques in man_made structure removal. The use of explosives in any application mustbe considered as a tool, no more or less dangerous than any other type of tool, when usedproperly. Accordingly, importance must be attached to recognizing the skill, integrity, andcare of those who use it. Massive amounts of information and help are available to assistthe rock blaster, ranging from the practical to the highly theoretical, but very littleinformation exists to guide anyone considering unleashing the power of explosives instructural demolition blasting. The planning and work required to execute such projects iscomplex, and the recognition of the different applications explosives can be applied to isthe first step."

Jan 1, 1993

By Gregg R. Gitschlag

There are more than 4,000 oil and gas structures present in the U. S. Gulf of Mexico. Approximately 100 structure removals occur each year and 66% of these are removed with explosives. From 1993-1995 an intensive study was conducted on the fish kill resulting from the explosive removal of 6 platforms off the Louisiana coast in water depths from 14-28 m (45-92 ft). After explosives were detonated, all floating fish and a sample of the dead fish which sank to the sea floor were collected.

Jan 1, 1997

By Heins Walter Wild

Detailed investigations on various configuration kinds of cut with respect to drilling-technological and blasting-technological properties as well as with respect to cost effectiveness have been carried out in Germany.

Jan 1, 1995

By Robert Hopler

In part four, the instrumentation used to detect the vibrations from the 1876 Hell Gate (East River, New York) reef-clearing blast was discussed. The apparatus consisted of cups of mercury and microscopes or other magnifying instruments to detect ripples or waves on the surface of the liquid metal.

Jan 1, 2007